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Report S OFFICE COPY STORMWATER MANAGEMENT REPORT S1T'2ol g - oco 27 Jacksons Store No. 530 RECEIVED11290 S.W. Bull Mountain Road eC1 22 2018 Portland, OR 97224 CITY 01- 116AR BUILDING DIVISION Property Owner: PacWest Energy, LLC dba Jacksons Food Stores, Inc. 3450 East Commercial Court Meridian, ID 83642 Engineer of Record: Chris Jensen, PE Barghausen Consulting Engineers, Inc. 18215 - 72nd Avenue South Kent, WA 98032 (425) 251-6222 cjensen@barghausen.com a October 1 , 2018 Our Job No. 17858 wr web mid O 18215 72ND AVENUE SOUTH KENT,WA 98032 (425)251-6222 (425)251-8782 FAX 8.}iit. BRANCH OFFICES• TUMWATER,WA OR♦ LONG BEACH,CA♦ ROSEVILLE,CA♦ SAN DIEGO,CA o www.barghausen.com a <��CN alYg DESIGNERS CERTIFICATION AND STATEMENT I hereby certify that this Stormwater Management Report for Jacksons Store No. 530 has been prepared by me or under my supervision and meets minimum standards of the City of Tigard and normal standards of engineering practice. I hereby acknowledge and agree that the jurisdiction does not and will not assume liability for the sufficiency, suitability,or performance of drainage facilities designed by me. rr tWi tia I I 1 17858.007.docx TABLE OF CONTENTS 1.0 PROJECT OVERVIEW AND DESCRIPTION 2.0 METHODOLOGY 3.0 ANALYSIS 4.0 ENGINEERING CONCLUSIONS 5.0 STORMWATER FACILITY DETAILS AND EXHIBITS 6.0 FINAL OPERATIONS AND MAINTENANCE (O&M) MANUAL AND O&M FORM 7.0 ADDITIONAL FORMS 8.0 ASSOCIATED REPORTS SUBMITTED EXHIBITS EXHIBIT A Vicinity Map EXHIBIT B Assessor's Map EXHIBIT C FEMA Map EXHIBIT D Soils Map EXHIBIT E Existing Conditions Map EXHIBIT F Post-Developed Basin Area Map EXHIBIT G Stormwater Basin Calculations EXHIBIT H Operations and Maintenance (O&M) Manual and O&M Form EXHIBIT I Geotechnical Report prepared by Hart-Crowser, dated September 12, 2017 I I 1.0 PROJECT OVERVIEW AND DESCRIPTION Size and Location of Project Site The project site is located at 11290 SW Bull Mountain Road in the City of Tigard, Oregon. The generally triangular parcel is 0.94 acres in size. Please refer to Exhibit A-E for the existing information. Type of Development/Proposed Improvements The proposed project includes the relocation and expansion of a convenience store and reconstruction of a fuel canopy. A trash enclosure and recycling enclosure is proposed for the site. Proposed on the west portion of the convenience store is a plaza area with trellis. Other site improvements include installation of stormwater facilities, installation of landscape, and street frontage improvements along SW Bull Mountain Road. Topography The site is generally elevated at approximately 308 feet above mean sea level with an existing surface that is generally level with slopes ranging from 1-7%. The surface is largely covered with concrete and asphalt pavements, with south portion of the site slope from north to south and the north portion sloping south to north. Soils The existing near surface soils on site consist of Cascade silt loam sloped at 3 to 7 percent. Cascade silt loam poorly drains with a hydraulic conductivity ranging from 0.06 to 0.2 inches per hour. The groundwater is mapped approximately 120 feet below ground surface in the site vicinity. Hydrology The project is located in the Tualatin Watershed.The 712 square mile basin provides storage for and releases water to Clean Water Services and a number of tributaries. The project site is within the limits of Clean Water Services jurisdiction. The area of the site is located in a minimal flood hazard zone (Zone X), per FEMA standards. Vegetation &Habitat The proposed project has minimal vegetation with a few existing maple trees to remain on site. Water Quality Sensitive Areas The proposed project does not have any know wetlands on-site. Property Zoning The project site is zoned General Commercial (GC), per the Zoning and Comprehensive Plan of Tigard City. This zone permits the operations of gasoline stations and is designed to accommodate establishments with a citywide trade area. Access The proposed project includes the relocation of a 40 foot driveway along Bull Mountain Road, and a 40 foot driveway adjacent to the property along the west side of the site. Concrete sidewalks are to be constructed along the north and southeast property lines. A bike lane along Bull Mountain Road is proposed for the site. 16 parking stalls, including 1 ADA compliant parking stall and bike racks are included in the proposal, alongside pedestrian and ADA compliant accessible pathways. 1 17858.007.docx Utility Availability and Conflicts In-service sanitary and stormwater systems exist along SW Bull Mountain Road and Pacific Highway. Existing telecommunications junction box and utility pole are located on the north property line and east property line, respectively. The location of the telecommunications service must be verified by the contractor for possible conflicts with existing utilities.The relocation of a water hydrant is proposed to connect to an existing water service line along the north property line. Site Analysis Permits Required Permits required for this project include a Public Facility Improvement Permit, ODOT Permit, 1200- CN General Permit, Building Permit, National Pollutant Discharge Elimination System (NPDES) Erosion Control Permit, Tree Permit. Existing vs. Post-Construction Conditions The existing site contains a convenience store and fueling dispensers with canopy. Please see the Existing Conditions Map located in Exhibit E for details of existing site conditions. Post-Construction includes the relocation of the convenience store and fueling dispensers with canopy and repaving the majority of the site. The perimeter of the site will be landscaped and a stormwater flow-through planter is proposed on the north corner of the site, bounded by SW Bull Mountain Road and Pacific Highway. Please see the Post-Developed Basin Map in Exhibit F. SI 2 17858.007.docx 2.0 METHODOLOGY Drainage at the Existing Site From review of the existing site survey, existing site drainage is routed north to SW Bull Mountain Road via a 12-inch public storm drain. There are nine (9)on-site catch basins that capture the flow from the site and route it to SW Bull Mountain Road where it enters existing City storm infrastructure and continues north. There are no anticipated impacts on existing drainage from the site development, as the proposed redevelopment will maintain existing drainage patters and reduce the flow rate by reduction in impervious area on the site and treating stormwater prior to discharge to existing City storm infrastructure. Infiltration Testing Results A Geotech Report prepared by Hart-Crowser dated September 12, 2017 (included in exhibit I) shows the results of infiltration tests. The infiltration test in the vicinity of the proposed stormwater planter yielded an infiltration rate of zero inches per hour. The Geotech has determined and recommended against the use of stormwater infiltration. Description of Proposed Stormwater Management Techniques The proposed project includes the redevelopment of more than 1,000 square-feet of impervious surface and as such Per Section 4.05.1 of the Design and Construction Standards of Clean Water Services, requires a permanent water quality approach. Based on the type of soils underlying the site and the infiltration testing completed by the geotechnical engineer, infiltration is not feasible for this site. Detaining and treating the stormwater will be accomplished through flow-through planter. As part of the project, there are also off-site improvement that require stormwater measures.An off-site curbside flow-through planter has been sized for the approximate area of the off-site impervious area that will be mitigated. The flow— through planter will be designed to remove 65 percent of the total phosphorus from the impervious surface area runoff as stated in Section 4.05.3.a of the Design and Construction Standards of Clean Water Services. The project proposes a reduction in impervious are from the existing developed condition and such reducing the off-site flow to the City infrastructure. • 3 17858.007.docx 401 3.0 ANALYSIS Design Assumptions The project proposes a reduction in impervious are from the existing developed condition and such reducing the off-site flow to the City infrastructure. Calculations have also been provided comparing the 25-year storm event for the existing condition and developed condition. The result of the comparing the existing condition and developed condition represents a reduction in flow from the site and detention is not required for the project since there is a reduction in impervious surface and off-site flow. The redeveloped site proposes to detain and treat stormwater runoff using the flow-through planter to achieve the water quality requirements. The on-site flow-through planter was designed to fit the site specific to meet the site development. Based on the impervious are the flow-planter was sized with 6% surface area for impervious area draining to it. The flow-through plater is designed with a under drain on overflow that is routed to the City storm system after the water has been treated. The off-site curb side flow-through planter was designed to treat an equivalent impervious are of the new impervious are that is being constructed as part of the off-site work. The curb side plant was sized with 6% surface area of the impervious area draining to it. Approved Stormwater Sizing Calculator Narrative Form and Printouts This project utilized the HydroCAD to compare the 25-year storm of 3.90in (per CWS detail 1280) for the existing site condition and the developed condition. The sizing for the flow-through planters are also proved using the standard form from the CWS LIDA handbook. Please see the documents in Exhibit G for the stormwater calculations. 4 17858.007.docx 4.0 ENGINEERING CONCLUSIONS It is believed that this facilities meets both the pollution reduction requirements and flow control requirements of the City of Tigard Stormwater Standards. The bottom of the basin will be over- excavated and backfilled with washed rock and a growing medium for pollution reduction for additional storage in the storm events. Exhibit G includes the post-developed hydrographs for the 25-year storm, and the post-developed hydrograph for the 25-year storm. Also included is the sizing worksheets for both flow-through planters. 5 17858.007.docx 5.0 STORMWATER FACILITY DETAILS I EXHIBITS The following exhibits are provided herein: EXHIBIT E Existing Conditions Map EXHIBIT F Post-Developed Basin Area Map EXHIBIT G Stormwater Calculations 6 17858.007.docx 6.0 FINAL OPERATIONS AND MAINTENANCE (O&M) PLAN AND O&M FORM The final Operations and Maintenance (O&M) Plan and O&M form are attached as Exhibit H. I 7 17858.007.docx 7.0 ADDITIONAL FORMS There are no additional forms to include. The project does not request any Special Circumstances. it 8 17858.007.docx 8.0 ASSOCIATED REPORTS SUBMITTED The following associated report is provided herein: EXHIBIT I Geotechnical Report prepared by Hart-Crowser, dated September 12, 2017 9 17858.007.docx Exhibit A Vicinity Map -49.1 SiN{PARKwSTw ._ - k.. Li -Ieucow a OJ,I ' i SWQ1.1r ,t`C'pFEK.,vr fist SW E£I a m. P ., 1rd d _,.. ,. .'' . . SW E AARDF ST SW U GAARDE-ST , ... ,- . SW MCDON. 4 1 5W MCFA . -- 1 ,-, ',+WtLccli SITE �s, SW INEZ `,I Lu ks i ? _ W ASPE5 w ,., t. i • Y Q,s 4 ,y 1i` <-a~ _. ,,z,:,..:'' Sl r tC�tB 1 f 1 t 5i' , ;,. err t! � 5 d . 4 „ � 5 'tJ+ WE "� , lC�n+�CFty 4 ' ,y ` ( *Atri nerfaeld .-Syy 5�9 , _G+�f#Ca‘urSe r Iid �. .,:, ,. oif I I rsa ,. 99 "= ~t1. .-7,,. - .:-SW:DURHAMLRD , y F rv� » rya» ti d 11 W 3 - if �.; REFERENCE: Rand McNally(2018) Scale For: Job Number Horizontal: N.T.S. Vertical: N/A Jacksons Store No. 530 17858 • ' A VS, 18215 72ND AVENUE SOUTH Tigard, Oregon er 't P vtA KENT, WA 98032 ID ' Z (425)251-6222 Title: (425)251-8782. VICINITY MAP �( � U1 0' CIVIL ENGINEERING,LAND PLANNING, Cr.ikc ENGts1' SURVEYING,ENVIRONMENTAL SERVICES DATE: 09/13/18 P.117000s1178581exhibitlgraphics117858 vmap.cdr II I Exhibit B Assessor Map J. 4n,r Onnn . 14 .45AC 51, tag co i 01,1111111111‘.. , L75 00 • • 155 08 1 20 00 t 4' 305 07 8 /36 00 252104.8 2s.„0,8 5 • 4743 40 00 2500 S 1 1 g 1:: :‘. 10 ; ?-,91 AC - UJ i- V. 70 AC .0 6 SW4 1-00W 306250 Z ' . , 306 00 , ,..• _°_ • .7,3,9 la'f,ti4494-255555A'5550/55453A2,/H2/3H-5-.1WA5,3HH.e,. ' 2C44,--- Er. 9' U N09-4i.00E i > til _ __ 305 10 NM 43 30E .1.41.99 22 CV 241)0 ....f 1 31 2500 ,.1 < 8 1700 C5 2.71 AC a- C6 CHRIST THE KINN LUTHERAN CHURCH .. 50 93 So. 9.. .. ,: 4.'s.,/ SW LAUREL GLEN Cl) T— '''''' tY/ , Tr• ‘4..? '.4,- 52 07 4' / . 1 800 :.= (i) 404 (<„ 1900 1 g 4, ,•44" 86 A56A3 ......„,.- /. / / 4f. -, 2 ge f, 14--— . /,00 '' 8 s.‘06 - -14111‘1 20.0 / ... 0 *' 3 c, 7367 . m__ .--- % % ,,./ . , 60 90 ------- / , ---- - BULt76. ' ,., 251 3'' 4? 4, g ,,„ 1., / 7, ,_, ---- 4,9, iCS 25.772) rdo.. r , ", / , i3Es 53 1 101 *%,,, / ,,, Z.‘:.:1 ‘ /+4'. / %4s / 4/' 1 .94 AC ' •18Q0 1 300 '4 t• / ,4- 7' „ti,t''' TRACI•E' Z,"4 2 ' SITE / / .41'. , ,f. I: Iwo. ... / / ,.. ,:- , . 4, , 13693 - SO AC .3 / 4 ,•- . • ,.. / / , * , / S -.., / , (CS 26 / .412, 4''Li' 2 / / 41., VAs? / , 44 87 '174' / / / 64"- 1200 / 0 , /' 414,10 5 03AC /' <(' / $$ .., , , 1/4.) / / , 4 T /' . 23 um 74 /t 4 , , / / / „ , 1 - ei) ,/ / ,/ ,„. 4' / / J,_ ,/ 4 / i 4,„ q 7 / / 4, ' 1 ,p. / •. 6 ,/ 7 52 • 1.7 39 Or 04) , REFERENCE: Washington County Department of Assessments(Sept. 2017) Scale. For: Job Number Horizontal: N.T.S. Vertical: N/A Jacksons Store No. 530 17858 c,t4A(/ 18215 72ND AVENUE SOUTH Tigard, Oregon 48- .tk ir 2dhill4, , v" KENT,WA 98032 , EtIii.: „Lik_Z (425)251-6222 Title: (425)251-8782 ASSESSOR MAP S • "011 ' CIVIL ENGINEERING,LAND PLANNING, G Et4o117*-6 SURVEYING,ENVIRONMENTAL SERVICES DATE:09/13/18 P\17000s1178581exhibitlgraphics117858 amap.cdr efiin Exhibit C FEMA Map obi MI mit tam '111 !;,d , . i 1 / I \ ( ----'‘N<.-----N --\. — SITE V NOTE: MAP AREA SHOWN ON/THIS PANEL IS LOCATED — WITHIN TOWNSHIP 1 SOUTH,/RANGE 1 WEST AND TOWNSHIP 2 SOUTH, RANGE 1 WEST. ------) 10 7 I , _ GTON COUNTY -- 7 :ORPORATED AREAS 410238 J LEGEND / OTHER AREAS ZONE X Areas determined to be outside the 0.2% / annual chance floodplain. REFERENCE: Federal Emergency Management Agency(Portion of Map 41067C0541E, Nov. 2016) Scale For: Job Number Horizontal. N.T.S. Vertical N/A Jacksons Store No. 530 17858 C,HA 18215 72ND AVENUE SOUTH Tigard, Oregon 4 'hp, ,S' KENT,WA 98032 CI)A&: z (425)251-6222 Title: (425)251-8782 FEMA MAP �- ,?"' CIVIL ENGINEERING,LAND PLANNING. `r'4'G ENGIHEP SURVEYING,ENVIRONMENTAL SERVICES DATE:09/13/18 P:117000s1178581exhibitlgraphics117858 fema cdr o co 2 x O W U) `.. j r 01 1161 ~. ' 44 . 4 . / ' 1 , But Mountain J , `'' , , ,,,,,441,...„......7.,, .01pm SITE O» ' , tr' 'F, :- " • st } a } /�� c' "'+ i Mtl+.vr+teyufrraMnrap.yry ,wW*irm+q{I e '1„ . CO dy REFERENCE: USDA, Natural Resources Conservation Service LEGEND: 7B = Cascade silt loam, 3-7%slopes Scale- For: Job Number Horizontal. N.T.S. Vertical N/A Jacksons Store No. 530 17858 ,iu ii- (�s 18215 72ND AVENUE SOUTH Tigard, Oregon "frKENT, WA 98032 m 'Z' (425)251-6222 Title: ,, 6 (425)251-8782 SOIL SURVEY MAP ur �,,o ` �' CIVIL ENGINEERING,LAND PLANNING, <r hC ENG1Ne4 SURVEYING,ENVIRONMENTAL SERVICES DATE:09/13/18 E P:I 17000s1178581exhibitlgraphicsl17858 soil.cdr mi 4 , ' fg$, ;I 1 a I-- �t Ei 1 SW rN SITEsw mutiL I :aEdi '"` Legend •1 1,1 Slopes Greater than 26% 4 CWS Potential Impact REFERENCE: www.tigard-or.gov(2018) Scale: For: Job Number Horizontal: N.T.S. Vertical. N/A Jacksons Store No. 530 17858 ,., �GHAvs 18215 72ND AVENUE SOUTH Tigard, Oregon KENT,WA 98032 Z (425)251-6222 Title: E • 4 Q. (425)251-8782 SENSITIVE AREAS s� g' CIVIL ENGINEERING,LAND PLANNING, EN GIS'6. SURVEYING,ENVIRONMENTAL SERVICES MAP DATE:09/13/18 P117000s117858Iexhibitlgraphics117858 sens-cdr „au mai Exhibit E Existing Conditions Map Exhibit F Post-Developed Basin Area Map tali 4103 lila titii Exhibit G Stormwater Basin Calculations 1 i 1 S --------------1> 2P Predeveloped Site Outlet Manhole Subcat' Reach, 'on• L� Routing Diagram for Predeveloped f — Prepared by Barghausen Consulting Engineers, Printed 9/25/2018 � HydroCAD®10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Predeveloped Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (sq-ft) (subcatchment-numbers) 5,663 74 >75% Grass cover, Good, HSG C (1S) 33,977 98 Paved parking, HSG C (1S) 39,640 95 TOTAL AREA 1 Predeveloped Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Page 3 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) Cover 0 0 5,663 0 0 5,663 >75% Grass cover, Good 0 0 33,977 0 0 33,977 Paved parking 0 0 39,640 0 0 39,640 TOTAL AREA a 1 1 I Predeveloped Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Page 4 Pipe Listing (all nodes) Line# Node In-Invert Out-Invert Length Slope n Diam/Width Height Inside-Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 2P 100.00 99.50 25.0 0.0200 0.010 12.0 0.0 0.0 011 Predeveloped Type ll 24-hr 25yr 24hr Rainfall=3.90" Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 sin 10544 ©2018 HydroCAD Software Solutions LLC Page 5 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SBUH method, Split Pervious/Imperv. Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlS: Predeveloped Site RunoffArea=39,640 sf 85.71% Impervious Runoff Depth>3.36" Tc=5.0 min CN=74/98 Runoff=4.05 cfs 11,086 cf Pond 2P: Outlet Manhole Peak Elev=102.34' Inflow=4.05 cfs 11,086 cf 12.0" Round Culvert n=0.010 L=25.0' S=0.0200 '/' Outflow=4.05 cfs 11,086 cf Total Runoff Area = 39,640 sf Runoff Volume = 11,086 cf Average Runoff Depth = 3.36" 14.29% Pervious = 5,663 sf 85.71% Impervious = 33,977 sf Predeveloped Type ll 24-hr 25yr 24hr Rainfall=3.90" Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 1 S: Predeveloped Site [49] Hint: Tc<2dt may require smaller dt Runoff = 4.05 cfs @ 11.95 hrs, Volume= 11,086 cf, Depth> 3.36" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 25yr 24hr Rainfall=3.90" Area (sf) CN Description 33,977 98 Paved parking, HSG C 5,663 74 >75% Grass cover, Good, HSG C 39,640 95 Weighted Average 5,663 74 14.29% Pervious Area 33,977 98 85.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Predeveloped Type ll 24-hr 25yr 24hr Rainfall=3.90" Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Page 7 Summary for Pond 2P: Outlet Manhole Inflow Area = 39,640 sf, 85.71% Impervious, Inflow Depth > 3.36" for 25yr 24hr event Inflow = 4.05 cfs @ 11.95 hrs, Volume= 11,086 cf Outflow = 4.05 cfs @ 11.95 hrs, Volume= 11,086 cf, Atten= 0%, Lag= 0.0 min Primary = 4.05 cfs @ 11.95 hrs, Volume= 11,086 cf Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 102.34'@ 11.95 hrs Flood Elev= 105.00' Device Routing Invert Outlet Devices #1 Primary 100.00' 12.0" Round Culvert L= 25.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 100.00'/ 99.50' S= 0.0200 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=4.01 cfs @ 11.95 hrs HW=102.31' (Free Discharge) L1=Culvert (Inlet Controls 4.01 cfs @ 5.11 fps) (CS A Developed Site Outlet Manhole Subcat Reach' "on. I Link Routing Diagram for Developed Prepared by Barghausen Consulting Engineers, Printed 9/25/2018 HydroCAD®10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Developed Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (sq-ft) (subcatchment-numbers) 8,712 74 >75% Grass cover, Good, HSG C (1S) 30,928 98 Paved parking, HSG C (1S) 39,640 93 TOTAL AREA Developed Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Page 3 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) Cover 0 0 8,712 0 0 8,712 >75% Grass cover, Good 0 0 30,928 0 0 30,928 Paved parking 0 0 39,640 0 0 39,640 TOTAL AREA Developed Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Page 4 Pipe Listing (all nodes) Line# Node In-Invert Out-Invert Length Slope n Diam/Width Height Inside-Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 2P 100.00 99.50 25.0 0.0200 0.010 12.0 0.0 0.0 Developed Type II 24-hr 25yr 24hr Rainfall=3.90" Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Page 5 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SBUH method, Split Pervious/Imperv. Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: Developed Site Runoff Area=39,640 sf 78.02% Impervious Runoff Depth>3.19" Tc=5.0 min CN=74/98 Runoff=3.87 cfs 10,542 cf Pond 2P: Outlet Manhole Peak Elev=102.18' Inflow=3.87 cfs 10,542 cf 12.0" Round Culvert n=0.010 L=25.0' S=0.0200 '/' Outflow=3.87 cfs 10,542 cf Total Runoff Area = 39,640 sf Runoff Volume = 10,542 cf Average Runoff Depth = 3.19" 21.98% Pervious = 8,712 sf 78.02% Impervious = 30,928 sf Developed Type ll 24-hr 25yr 24hr Rainfall=3.90" Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 1S: Developed Site [49] Hint: Tc<2dt may require smaller dt Runoff = 3.87 cfs @ 11.96 hrs, Volume= 10,542 cf, Depth> 3.19" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 25yr 24hr Rainfall=3.90" Area (sf) CN Description 30,928 98 Paved parking, HSG C 8,712 74 >75% Grass cover, Good, HSG C 39,640 93 Weighted Average 8,712 74 21.98% Pervious Area 30,928 98 78.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, } Developed Type ll 24-hr 25yr 24hr Rainfall=3.90" Prepared by Barghausen Consulting Engineers Printed 9/25/2018 HydroCAD® 10.00-22 s/n 10544 ©2018 HydroCAD Software Solutions LLC Page 7 Summary for Pond 2P: Outlet Manhole Inflow Area = 39,640 sf, 78.02% Impervious, Inflow Depth > 3.19" for 25yr 24hr event Inflow = 3.87 cfs @ 11.96 hrs, Volume= 10,542 cf Outflow = 3.87 cfs @ 11.96 hrs, Volume= 10,542 cf, Atten= 0%, Lag= 0.0 min Primary = 3.87 cfs @ 11.96 hrs, Volume= 10,542 cf Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 102.18'@ 11.95 hrs Flood Elev= 105.00' Device Routing Invert Outlet Devices #1 Primary 100.00' 12.0" Round Culvert L= 25.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 100.00'/ 99.50' S= 0.0200 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=3.83 cfs @ 11.96 hrs HW=102.15' (Free Discharge) 1-1=Culvert (Inlet Controls 3.83 cfs @ 4.88 fps) Clean Wafer Services LIDA Sizing Farm Project Title: Jacksons Food Store#530 On-site SW Bull Mountain Rd Tigard,OR Project Location: 11290 _.. g Contact Name/Title/Company: Jack Davis Phone/e-mail: jack.davisl@jacksons.com STEP 1: Determine Impervious Area Requiring Treatment Total Site Area (acres): 0.91 Total Existing Impervious Area (sq.ft.): 33,977 Proposed New Impervious Area (sq.ft.): 30,928 Impervious Area Requiring Treatment (sq.ft.) 30,928 (Refer to Design &Construction Standards Chapter 4 for instructions to calculate this area, which will be less than or equal to the new plus existing site impervious area.) STEP 2: Deduct Impervious Area LIDA Credits Porous Pavement (sq. ft.): Green Roof (sq. ft.): 1 0 Other Credits as approved (sq. ft.): 0 Total Credits (sq. ft.): o.n.,..-.._ Remaining Impervious area (sq. ft.) (Total from Step 1 — Total Credits): 0 STEP 3: Size LIDA Facilities for Remaining Impervious Area IA: Impervious SF, Sizing LIDA facility size area treated Factor (sq.ft.) (IA x SF) (sq.ft.) Infiltration Planters/Rain 0.06 Garden Flow-through Planter 30.928 0.06 1,856 LIDA Swale 0.06 Vegetated Filter Strip 0.06 Total Impervious 30,928 (*Must equal total from Step 2 or additional LIDA Area treated (sq.ft.) facilities or Water Quality Facilities must be added.) Ilea Mater Services Low Impact Development Approaches Handbook 19 Clean Water Services LIDA Sizing Form Project Title: Jacksons Food Store#530 Off-site 11290 SW Bull Mountain Rd Tigard,OR Project Location: ' Contact Name/Title/Company: Jack Davis Phone/e-mail: jack.davisl@jacksons.com STEP 1: Determine Impervious Area Requiring Treatment Total Site Area (acres): 0.09 Total Existing Impervious Area (sq.ft.): 2,614 Proposed New Impervious Area (sq.ft.): 3,049 Impervious Area Requiring Treatment (sq.ft.) 3,049 (Refer to Design &Construction Standards Chapter 4 for instructions to calculate this area, which will be less than or equal to the new plus existing site impervious area.) STEP 2: Deduct Impervious Area LIDA Credits Porous Pavement (sq. ft.): o Green Roof (sq. ft.): o _ Other Credits as approved (sq. ft.): Total Credits (sq. ft.): 0 Remaining Impervious area (sq. ft.) (Total from Step 1 — Total Credits): STEP 3: Size LIDA Facilities for Remaining Impervious Area IA: Impervious SF, Sizing LIDA facility size area treated Factor (sq.ft.) (IA x SF) (sq.ft.) Infiltration Planters/Rain 0.06 Garden Flow-through Planter 3,049 0.06 183 LIDA Swale 0.06 Vegetated Filter Strip 0.06 Total Impervious (`Must equal total from Step 2 or additional LIDA 3,049 facilities or Water Quality Facilities must be Area treated (sq.ft.) added.) i Clean Water Services Low Impact Development Approaches Handbook 19 ,u11M Exhibit H Operations and Maintenance (O&M ) Manual and O&M Form tWY IL4.3 0 Flow-Through Planter Operation and Maintenance Plan Annual inspections are required. It is recommended that the facility is inspected on a monthly basis to ensure proper function.The plan below describes A' inspection and maintenance activities, and may be used as an inspection log. Contact the design engineer, Clean Water Services or City representative for more information. Identified Problem Condition to Check for Maintenance Activity Maintenance Timing 6/Task Complete Comments Sediment Accumulation in Sediment depth exceeds 3 inches Remove sediment from treatment Treatment Area area. Ensure planter is level from side to side and drains freely toward SUMMER FALL gIJ outlet;no standing water within 24 rD hours after any major storm(1-inch in Ideally in dry season 24 hours) CD �'. Erosion Erosion or channelization that impacts Repair eroded areas and stabilized or effects the function of the facility or using proper erosion control mea- creates a safety concern sures Establish appropriate vegetation FALL WINTER SPRING as needed Inspect after major storm (1-inch in 24 hours) L ro Standing Water Standing water in the planter between Remove sediment or trash blockages. storms that does not drain freely. Grade out areas of mounding and Water should drain after 24 hours of improve end to end grade so there is WINTER SPRING dry weather. no standing water. rD Flow Not Distributed Flow unevenly distributed through Level the spreader and clean so Evenly planter width due to uneven or that flows spread evenly over entire clogged flow spreader planter width WINTER SPRING CD Obstructed Inlet/Outlet Material such as vegetation, sediment, Remove blockages from facility trash is blocking more than 10%of WINTER SPRING the inlet/outlet pipe Inspect after major storm (1-inch in 24 hours) I Ln Flow-Through Planter Operation and Maintenance Plan (continued) Annual inspections are required. It is recommended that the facility is inspected on a monthly basis to ensure proper function.The plan below describes inspection and maintenance activities, and may be used as an inspection log. Contact the design engineer, Clean Water Services or City representative for more information. n Identified Problem Condition to Check for Maintenance Activity Maintenance Timing ✓Task Complete Comments d .-r Poor Vegetation Coverage 80%survival of approved vegetation Determine cause of poor growth and ` 0 and no bare areas large enough to correct the condition;replant with . " affect function of facility. plugs or containerized plants per ap- c) SPRING FALL proved plans and applicable standards Ideal time to plant is spring and at time of construction.Remove ex- fall seasons cessive weeds and all invasive plants. v Invasive Vegetation as Invasive vegetation found in facility. Remove excessive weeds and all in outlined in Appendix A Examples include:Himalayan Blackber- invasive plants.Attempt to control 1) ry;Reed Canary Grass;Teasel, even if complete eradication is not SPRING SUMMER FALL co English Ivy,Nightshade,Clematis, feasible. Refer to Clean Water Services Cattail,Thistle Integrated Pest Management Plan for appropriate control methods,includ- a1 ing proper use of chemical treatment. ra Excessive Vegetation Vegetation grows so tall it competes Prune over-hanging limbs,if possible; o with or shades approved emergent remove brushy vegetation as needed. SPRING n wetland grass/shrubs; interferes with Prune emergent wetland grass/shrubs Ideal time to prune emergent a.ro access or becomes a fire danger that have become overgrown. wetland grass is spring Vector Control Evidence of rodents or water flowing Repair damage to facility. Remove As Needed through facility via rodent holes.Harm- harmful insects,call professional if ful insects such as wasps or hornets needed. Refer to Clean Water Services present Integrated Pest Management Plan for c management options. "/ a t I s Flow-Through Planter Operation and Maintenance Plan (continued) Annual inspections are required. It is recommended that the facility is inspected on a monthly basis to ensure proper function.The plan below describes inspection and maintenance activities, and may be used as an inspection log. Contact the design engineer, Clean Water Services or City representative for more information. CD Identified Problem Condition to Check for Maintenance Activity Maintenance Timing a/Task Complete Comments Trash and Debris Visual evidence of trash,debris or Remove and dispose of trash and debris i dumping. from facility. Dispose of properly -0_ SPRING SUMMER FALL WINTER rD coContamination and Evidence of oil,gasoline,contaminants, If contaminants or pollutants present, Pollution or other pollutants. Look for sheens, coordinate removal/cleanup with local ` *, odor or signs of contamination. jurisdiction. SPRING SUMMER FALL WINTER r-r Outlet Structure Damaged Grate or overflow structure is missing Repair or replace outlet structure. As Needed or only partially in place and may have missing or broken grate members. rD rD 0 3 rD CD ro 1_ l Catch Basin Operation and Maintenance Plan Annual inspections are required.The plan below describes maintenance and inspection activities and may be used as an inspection log. Contact the design engineer, Clean Water Services or City representative for more information. Identified Problem Condition to Check for Maintenance Activity Inspection Frequency d Task Complete Comments 0.) Vermin and Odors Dead animals or vegetation is Remove dead animals or vegetation Annually or as needed CD observed in catchbasin. that is generating odors or dangerous F gases(e.g., methane). Dispose of { CD properly v Contamination and Evidence of oil,gasoline,contaminants, Determine source(s)of contaminant Monthly from November Pollution or other pollutants and coordinate removal/cleanup with through May local water quality response agency Basin Settlement or Failure of basin has created a safety, Replace or repair basin to design Annually Required Misalignment function,or design problem standards aVegetation,trash or Vegetation or other debris is blocking Remove material that is blocking Annually or as needed -o other debris blocking basin more than 20%of the basin opening basin opening and dispose of properly 0 opening 2 Inlet/Outlet pipe blockage Sediment,trash or vegetation blocking If material is blocking more than 1/3 Annually or as needed or damaged inlet or outlet pipe.Vegetation in inlet/ of its capacity clear blockage.Remove outlet pipe joints causing separation vegetation in the pipe joints if large o enough to cause damage c--) a Grate damaged,missing or Grate is missing or only partially in Ensure grate is in place and meets Annually or as needed CD not in place place;may have missing or broken design standards.Any open structure grate members needs maintenance; replace grate if missing Catch Basin Cover Catch basin cover is missing or only Repair or replace cover. Any open Annually or as needed (manhole cover)not in partially in place catch basin requires maintenance iy place immediately r Catch Basin Cover difficult One maintenance person cannot Determine if cover is rusted/seized or Annually or as needed �., to Remove remove lid using normal lifting pressure; damaged. Repair lid to allow access . difficult to access for maintenance n � Catch Basin Operation and Maintenance Plan (continued) Annual inspections are required. The plan below describes maintenance and inspection activities and may be used as an inspection log. Contact the design engineer, Clean Water Services or Cityrepresentative for more information. 9 rr Identified Problem Condition to Check for Maintenance Activity Inspection Frequency ✓Task Complete Comments Structure damage to frame Frame not sitting flush on top slab Repair frame so that it is firmly attached Annually Required or top slab (more than 3 inch between frame and and sits flush on top of slab. If holes top slab);frame not securely attached. are large enough to allow material to Cracks or holes present. enter basin repair is needed Ladder Rungs Unsafe Ladder is unsafe(missing rungs,not Ladder meets design standards and Annually Required CD securely attached,misalignment,rust, allows safe access for maintenance ,o cracks,sharp edges,etc.) person Fracture or cracks in Basin Grout fill separated or cracked wider Basin replaced or repaired to design Annually Required Walls and Bottom than 'rz inch and longer than 1 foot standards. Maintenance person at the joint of any inlet/outlet pipe; should determine if the structure is evidence of soil entering through cracks unsound Trash & Debris/Sediment Trash,debris or sediment in the basin Remove material from sump.Attempt Monthly. Inspect after any 3 in sump exceeds 50%of the sump depth from to determine where source of material major storm(1 inch in 24 co the bottom of basin to invert of the is coming from to reduce future input hours).Annually Required ° lowest pipe into or out of the basin into sump a v ' 3 ro o' (31 ( 0 Exhibit I Geotechnical Report • . • .r..r3+$:dSft 4:AYaTi'NfM'S� ' C 9 a ..•• .au 4 FY'T - $RRTSe ryy1Y i # I ,. I. , -,. r_•-,:.•-t,4';,:•4 4..y4,, y' ,'+$ t n c' • 44o-� r 1:rt • jr p � � 644, t a; { t. ' ' :4 „$ .,f . , 1,," � Report ofMr Geotechnical Engineering k iri �„ r P Services g °z< }# e,: 4. Jacksons Store #530 YES€y{, Jt , � e "* �Y t ` . ,,, �' '. 'y�{ ° � r �� 11290 SW Bull Mountain Road Rf, ig r`� { S y,a 4 . >` Tigard, Oregon r_ aka {av"r 3" Ax .. r , ..e'� ii, 1.:1,,,,,,,,,10,,••,:..4.1.:..,:„,,04401,,tispiii*,,:•:„.•,....,,,i,,;:,:.4r7,,,,,,- '-lie,.i::p,,4.0 :4,10;04.1#40,,,,,.,,,-,„:..,,,,,,,„,:.- .;,.„ i Prepared for R{<x.a, `,{; ` � ' a,° " PacWest Energy, LLC � r k F. e R i 5 i,,j 71.5 A . ..aYI 4 .e - .. ...fr 9 � t•as }},� 'yam y 2 September 12, 2017 15927-11 r , ��; 'n ss s:% ` {:'„ ' ia(4 '{ ,..: a3 >k.''?'s§`Y tip" rt F t # 4S ty:. •]•• rr $zp ''' r {. roirttgt. ¢i s8 s' + r 4 a z $it i {{yyvil a�dil {rt zt. s $ u a '4- 3 b .= t s -. 3`s, F� ,Si+fi z3R i + [F i& ,a ��t Y g + r ay r^e�d aS t i' fir;, f,�_ '��t�f;`she' t �. r�,,s�"6R� q€� 0 y«.�a"� V 4 t 9i 3 :"dam rr , ,4 r ,�-�� a i.q0:#�'' 4t r� r,t«^fie {xis« � 40# 01• sr t �`e .« ''`' (.. �� f' 3r,144144,0N4. �p 1 414• ,�+,� _ y 33�i R 5 ... _. -. laii .. F rc' ffN n i HIVITCROVIISEil 'RIPPtR { 4 C.. I 54..E� iM 3F� 3k j A AWN harbc'owsor,corn H WSE 1 saY idN Report of Geotechnical Engineering Services Jacksons Store #530 11290 SW Bull Mountain Road Tigard, Oregon Prepared for PacWest Energy, LLC ,xu September 12, 2017 Ii14 15927-11 Prepared by Hart Crowser, Inc. ;t:Wter„ r'i is 63,E . J. Daniel J. Trisler, PE, GE Timothy W. Blackwood, PE, GE, CEG Senior Associate, Geotechnical Engineer Principal, Geotechnical Engineer 300 West 15th Street Vancouver, Washington 98660-2927 Tel 360.448.4189 d IIYY Contents awsk 1.0 INTRODUCTION 1 2.0 SCOPE OF SERVICES 1 3.0 SITE CONDITIONS 2 3.1 Surface Conditions 2 3.2 Geologic and Soil Mapping 2 3.2.1 Geologic Mapping 2 3.2.2 Soil Mapping 3 3.2.3 Prior Explorations 3 r.3 3.3 Subsurface Conditions 3 3.3.1 General 3 3.3.1 Surfacing 3 3.3.2 Colluvial Soil 4 3.3.3 Bedrock 4 3.3.4 Groundwater 4 3.3.5 Infiltration 4 4.0 GEOLOGIC HAZARDS ASSESSMENT 5 YIKt 4.1 Seismic Hazard Mapping 5 4.2 Seismic Considerations 5 4.3 Seismic Shaking 6 4.4 Ground Motion Amplification (Site Class) 6 4.5 Surface Fault Rupture 6 5.0 CONCLUSIONS 6 6.0 STRUCTURAL DESIGN RECOMMENDATIONS 7 6.1 General 7 6.2 Building Foundation Support Recommendations 7 6.2.1 Dimensions and Design Parameters 7 6.2.2 Settlement 8 6.2.3 Foundation Subgrade Preparation 8 no" 6.3 Canopy Foundation Support Recommendations 8 6.3.1 General 8 6.3.2 Axial Capacity 8 6.3.3 Lateral Resistance 8 6.3.4 Settlement 9 6.3.5 Construction Considerations 9 Eqi 6.4 Seismic Design 9 6.5 Floor Slabs 10 11111 V 15927-11 HIIRTCROWSER September 12,2017 ii Contents 7.0 DRAINAGE DESIGN RECOMMENDATIONS 10 7.1 Temporary Drainage 10 7.2 Surface Drainage 10 7.3 Subsurface Drainage 11 7.4 Infiltration Systems 11 8.0 PAVEMENT DESIGN RECOMMENDATIONS 11 8.1 General 11 8.2 Assumptions and Design Parameters 11 8.3 Pavement Sections 12 8.4 Pavement Materials 13 8.4.1 Flexible AC 13 8.4.2 Rigid PCC 13 8.4.3 Aggregate Base 13 9.0 EARTHWORKS RECOMMENDATIONS 14 9.1 General 14 ;ni 9.2 Site Preparation 14 9.2.1 Demolition 14 9.2.2 Stripping 14 9.2.3 Subgrade Preparation and Evaluation 15 9.2.4 Wet Soil/Wet Weather Construction 15 9.3 Excavation 15 9.3.1 General 15 9.3.2 Excavation Stability 16 9.3.3 Dewatering 17 9.4 Structural Fill and Backfill 17 9.4.1 On-Site Soils 17 9.4.2 Imported Select Structural Fill 17 9.4.3 Aggregate Base 18 9.4.4 Trench Backfill 18 9.4.5 Stabilization Materials 19 9.4.6 Recycled Materials 19 9.5 Fill Placement and Compaction 20 10.0 CONSTRUCTION OBSERVATIONS 21 11.0 LIMITATIONS 22 12.0 REFERENCES 22 15927-11 3I September 12,2017 H/IIRTcfOWSER r ua Contents iii TABLES 1 Seismic Design Parameters 9 2 AC Pavement Sections 12 ""' 3 PCC Pavement Sections 13 4 Guidelines for Uncompacted Lift Thickness 20 air 5 Fill Compaction Criteria 21 FIGURES 1 Vicinity Map 2 Site and Exploration Plan APPENDIX A Field Explorations APPENDIX B all Laboratory Testing 410 AMA 15927-11 HaRTCAVIIIISER September 12,2017 arr 4110 dig Report of Geotechnical Engineering Services Jacksons Store #530 11290 SW Bull Mountain Road Tigard, Oregon 1.0 INTRODUCTION Hart Crowser, Inc. is pleased to submit our report of geotechnical engineering services for the proposed Jacksons Store#530 redevelopment project in Tigard, Oregon. Our work was completed in atm general accordance with our approved proposal dated May 30, 2017. The existing 0.9-acre parcel is currently occupied by an existing Shell fueling station, car wash, and approximately 1,100-square-foot convenience store. The existing convenience store,fueling canopy, and car wash will be demolished, and a new 4,250-square-foot Jacksons Store building and 2,400-square-foot fueling canopy will be constructed. Also,the parking areas will be reconfigured and landscaping added. The existing underground storage tank farm will remain. Stormwater runoff will be discharged into on-site infiltration facilities constructed at the site, if feasible, or will be detained and then discharged off-site. The location of the site is shown on Figure 1.The existing site layout is shown on Figure 2. Appendix A contains logs of subsurface explorations we completed and a description of our exploration methods and equipment.Appendix B contains the results of our laboratory testing. 2.0 SCOPE OF SERVICES The purpose of our work was to evaluate subsurface conditions for the proposed development and to provide geotechnical engineering services for design of specific project elements. Our complete scope of work was described in our May 30, 2017 proposal and included the following tasks. • Reviewed relevant, readily available geologic maps that cover the site vicinity to evaluate geologic hazards and regional soil mapping. • Conducted a field investigation, including: • Notified the "One Call" service for public utility locates and engaged the services of a private utility locating service to further identify on-site utilities; • Advanced five borings to depths between approximately 6 to 20 feet below ground surface (bgs) near the locations of the proposed building improvements and potential stormwater facilities; • Maintained logs of the soils encountered in the explorations and collected soil samples for laboratory testing; and • Completed in situ infiltration tests adjacent to three of the borings. ss 11 15927-11 Hit. September 12,2017 AWY 2 Jacksons Store#530 • Conducted a program of laboratory testing on select soil samples, including moisture content, grain size distribution, and Atterberg limits determinations. ■ Conducted engineering analyses to evaluate seismic hazards, infiltration, foundations, and pavements. ■ Prepared this report outlining our findings and recommendations, including information related to the following: • Subsurface soil and groundwater conditions, • Seismic and ground settlement hazards, • Site preparation and grading, • Utility trench construction, • Foundation and floor slab-on-grade design parameters, • Infiltration considerations, and • Pavement design. • Provided project management and support services, including coordinating staff and subcontractors and conducting telephone consultations and email communications with you and the design team. 3.0 SITE CONDITIONS 3.1 Surface Conditions The existing property is a 0.9-acre generally triangular parcel bound by SW Pacific Highway to the east and southeast, SW Bull Mountain Road to the north, a pre-school to the west, and apartments to the southwest. The site is generally level,with a gentle slope from north to south. Elevations in the majority of the site are approximately 308 feet above mean sea level (MSL). The ground at the site is generally covered with asphalt and concrete pavements. Landscaping at the site is limited, except for ivy and mature evergreen and small deciduous trees along the eastern property limits. 3.2 Geologic and Soil Mapping 3.2.1 Geologic Mapping Geology in the vicinity of the site is mapped in U.S. Geologic Survey(USGS (Open-File Report 2005-1305 (USGS 2006) derived from the geologic map of Walker and MacLeod (1991) at the 1:500,000 scale. The geology of the site is mapped as Columbia River Basalt Group and related flows (Tc). Tc is described as Miocene subaerial basalt and minor andesite lava flows and flow breccia; submarine palagonitic tuff and pillow complexes of the Columbia River Basalt Group; and locally includes invasive basalt flows. Flows locally grade laterally into subaqueous pillow-palagonite complexes and bedded palagonitic tuff and breccia. In places it includes tuffaceous sedimentary interbeds, and joints commonly coated with nontronite and other clayey alteration products. Our explorations generally confirm the mapped geology. VP 15927-11 111 September 12,2017 HARTCROWSER arr Jacksons Store#530 3 Local well logs and previous explorations as a part of a Phase II Environmental Site Assessment(ESA) by Delta Environmental Consultants (DEC) (DEC 2007) are consistent with the mapping. mi" Groundwater is mapped by the USGS(Snyder, 2008)as being approximately 120 feet bgs in the site vicinity. 3.2.2 Soil Mapping The near surface soils at the site have been mapped in the U.S. Department of Agriculture (USDA) ,,,, online web soil survey(USDA 2006).According to the USDA resource, the near-surface soils at the site consist of Cascade silt loam, 3 to 7 percent slopes.The Cascade silt loam unit is described as silt loam that is somewhat poorly drained with a hydraulic conductivity(permeability) ranging from 0.06 to ,tir 0.2 inches per hour. 3.2.3 Prior Explorations ctAk A Phase II ESA was completed at the site in 2007 by DEC(DEC 2007). As part of their investigation, DEC advanced eight direct push probes at the site. The probes typically encountered silt with gravel and encountered refusal on basalt material at depths of 5 to 17 feet bgs. No groundwater was detected in any of the borings. 3.3 Subsurface Conditions 3.3.1 General 1114i We explored subsurface conditions at the site by drilling five borings ranging in depth from 6.5 to 20.4 feet bgs on July 5, 2017. The exploration locations are shown on Figure 2. Appendix A summarizes our exploration methods and presents our boring logs. Appendix B contains the results of our laboratory testing on select soil samples. Subsurface conditions encountered at the site included a surficial layer of topsoil or pavement overlying residual soil with weathered basalt bedrock at depths of approximately 5 to 20 feet bgs. These materials are discussed in detail in the paragraphs below. 3.3.1 Surfacing Borings B-1, B-2, B-4, and B-5 were drilled in paved areas and encountered 6 inches of asphalt underlain by 12 to 18 inches of angular base aggregate. The pavement at the site is in generally fair condition with minor surface cracking and previously performed crack filling repairs. Boring B-3 was performed in the northeast corner of the site in a grassy area adjacent to Bull Mountain Road. It penetrated 2 inches of topsoil with roots and organics. 15927-12 HARTCROWSER September 11,2017 Vuw 4 Jacksons Store#530 3.3.2 Colluvial Soil Underlying the surfacing,we encountered colluvial (possibly residual)soils to depths of 5 to 20 feet bgs. These materials consisted of layers of dry to wet, brown silty sand, sandy silt,and silt. Standard Penetration Test(SPT) blow counts (N-values) in the silt generally ranged from 4 to 20 blows per foot(bpf), indicating soft to very stiff relative consistencies. The average relative consistency is medium stiff to stiff. Laboratory moisture testing of the silt soils resulted in water contents ranging from 18 to 31 percent. Grain size distribution testing indicated that the silt soils had fines contents (percent by dry weight passing the#200 sieve) ranging from 73 to 95 percent. N-values in the sands generally ranged from 8 to 22 bpf, indicating a loose to medium dense condition. Laboratory moisture testing of the sand soils resulted in water contents ranging from 26 to 29 percent. Grain size distribution testing indicated that the sand soils had fines contents (percent by dry weight passing the#200 sieve) ranging from 39 to 46 percent. Atterberg limit tests in these soils yielded liquid limits of 35 to 42 percent and plasticity indexes of 7 to 16 percent, indicating that the fine soil component of the sandy soil is a low plasticity silt(Unified Soil Classification System [USCS] ML). 3.3.3 Bedrock At depths ranging from 5 to 20 feet bgs,the borings encountered decomposed basalt that consisted of silty sand, silty gravel, and gravel with silt that had relict rock structure. We interpret this material to be derived from in-place weathering of the underlying Columbia River basalt. Within 0.25 to 0.75 foot of encountering the decomposed material,the borings encountered SPT refusal on hard basalt. A contour map of the anticipated depth to hard bedrock at the site is provided on Figure 2. Depths to hard bedrock were estimated from all boring logs available at the site including those performed for this investigation and the Phase II ESA by Delta (2007). Bedrock is deepest(20 feet) in the northeast corner of the site and shallowest(5.2 feet) in the southwest corner. 3.3.4 Groundwater Water seepage was encountered in borings B-2 and B-3 at depths of 7.7 and 8 feet bgs, respectively. However, no groundwater was encountered in the other borings. The regional groundwater is mapped as being approximately 120 feet bgs in the site vicinity. We suspect that this water may have been irrigation water that had soaked into the ground, as opposed to actual groundwater, although it could still be from natural seepage. Additionally,we anticipate that infiltrating precipitation or irrigation water will seasonally perch atop the hard bedrock encountered below the site. 3.3.5 Infiltration Three infiltration tests were conducted adjacent borings B-1, B-2, and B-3, in general accordance with the City of Portland (City)Stormwater Management Manual (Portland 2016). At B-1 and B-3, no significant drop in water level was observed over the duration of the test indicating a field infiltration rate of effectively 0 inches/hour. At B-2, an unfactored infiltration rate of 6 inches/hour was observed in the test. Our infiltration test methods are described in Appendix A, and recommendations for application of our results to on-site stormwater design are provided in Section 7.4—Infiltration Systems. 15927-11 8.1 September 12,2017 H/{RTO ?ON/SER Jacksons Store#530 5 4.0 GEOLOGIC HAZARDS ASSESSMENT 4.1 Seismic Hazard Mapping 4i Overall seismic hazards for this area have been mapped by the Department of Geology and Mineral Industries(DOGAMI) Interpretive Map Series IMS-1 (Mabey et al. 1997) and the DOGAMI Statewide Hazard Viewer online portal (HAZVU 2017). These publications include maps for overall seismic hazard, liquefaction,ground amplification, and seismically induced landsliding. Mabey et al. (1997) mapped the overall earthquake hazard at the project site as being in Zone D (lowest hazard) where overall earthquake hazard is designated to vary between Zones A(highest hazard)and D (lowest hazard).The individual hazards are designated to vary from Zone 3 (highest hazard)to "No Hazard" described as "possible only where there are unusual localized conditions."The ground motion amplification hazard at the site is mapped as Zone 1 (low hazard). Seismically induced landsliding and soil liquefaction are both mapped as"No Hazard." Based on our explorations and experience in the area,we are in general agreement with the mapped hazards at the site and consider the potential for liquefaction and seismically induced landsliding to be low. 4.2 Seismic Considerations The seismicity of the Portland Basin is controlled by the Portland Hills-Clackamas Fault zone and the Cascadia Subduction Zone. Contributions from each of these sources to the total site seismic hazard were evaluated using the USGS 2008 Interactive Deaggregations (USGS 2013). Intraslab and Interface Sources Subduction zones are characterized by the interaction of the oceanic Juan de Fuca Plate and continental North American Plate. As the oceanic plate subducts beneath the continental plate, the two plates lock together. As the plates move together, stresses that can be thought of as similar to a spring build in the overlying continental plate. When the magnitude of the stresses become large enough to overcome the stresses locking the plates together,the plates will suddenly rupture causing an interface earthquake. Interface earthquakes(such as the 2011 magnitude M9.0 Tohoku earthquake in northern Japan) are some of the largest magnitude earthquakes on record. Intraslab earthquakes originate from a deeper zone of seismicity that is associated with bending and breaking of the subducting Juan de Fuca Plate. Intraslab earthquakes(such as the 2001 magnitude M7.0 Nisqually earthquake in west central Washington)occur at depths of 40 to 70 kilometers(km) and can produce earthquakes with magnitudes up to and greater than magnitude M7.0. Crustal Sources Shallow crustal faults are caused by cracking of the continental crust resulting from the stress that builds as the subduction zone plates remain locked together. Many small crustal faults are mapped near the site that are a part of the greater Portland Hills-Clackamas Fault Zone(Personius 2002). 1171 15927-12 MJ.U?TG2'OUVSU? September 11,2017 6 Jacksons Store#530 4.3 Seismic Shaking We evaluated potential seismic shaking at the site using data obtained from the USGS Seismic Design Maps(USGS 2014). The expected peak ground acceleration (PGA)of the bedrock having a 2 percent probability of exceedance in 50 years (2,475-year return period) is 0.404 g. This value represents the peak acceleration on bedrock beneath the site and does not account for ground motion amplification due to site-specific effects. The PGA at the ground surface is determined by applying a site class amplification factor to the peak bedrock acceleration. Refer to Section 4.4-Ground Motion Amplification(Site Class)for a discussion of ground motion amplification. We obtained a deaggregation of the seismic sources contributing to the expected peak bedrock acceleration shown above from the National Seismic Hazard Mapping Project website (USGS 2014). Seismic sources contributing to this potential ground shaking included intraplate (e.g., Cascadia Subduction Zone), interplate, and crustal faults. The data indicate that the "mean source"for shaking at the site is a magnitude (Mw)=7.74 quake with an epicenter approximately 57.5 km from the site. The "modal source"for shaking at the site is Mw=9.34 quake with an epicenter approximately 72.6 km from the site. The modal source generally signifies the earthquake with one of the highest contributions to the site earthquake hazard. In this instance, a full rupture of the Cascadia Subduction Zone wi►l control a significant portion of the site seismic hazard. The mean source represents other sources of significant seismicity including the Portland Hills Fault and the intraplate subduction zone. 4.4 Ground Motion Amplification (Site Class) The "Site Class" is a designation used by the 2012 International Building Code (IBC) (ICC 2012)and 2014 Oregon Structural Specialty Code(OSSC) (ICC 2014)to quantify ground motion amplification. The classification is based on the stiffness in the upper 100 feet of soil and bedrock materials at a site. This information leads us to classify the site as Site Class C. 4.5 Surface Fault Rupture Based on our review of available geologic maps (Personius 2002),the closest know fault to the site is the Oatfield Fault located approximately 0.6 mile east of the site. Based on the mapped location of faults,we anticipate the hazard from ground fault rupture to the site to be low, unless occurring on an unmapped or unknown fault underlying the site. 5.0 CONCLUSIONS Based on our explorations,testing, and analyses, it is our opinion that the site is suitable for the proposed use, provided the recommendations in this report are included in design and construction. We offer the following general summary of our conclusions. ■ The site soils above the bedrock are moderately weak and compressible,though are suitable for lightly loaded foundations. If foundation loads heavier than those noted in the following sections are proposed,then we should be contacted for additional information. 171 15927-11 September 12,2017 HARTCROWSER Jacksons Store#530 7 kmo ■ Much of the near-surface soils are fine-grained and moisture sensitive. They will be easily disturbed by construction activities when they are exposed. The contractor should protect the subgrade from disturbance during construction. ■ Our field testing showed that the fine-grained soils have no practical infiltration capacity,while the sandy layer we tested has moderate capacity. However, it is unknow if the sandy layer is laterally continuous at the site. Also,the sandy layer is underlain by impermeable silt and bedrock,which may tend to perch water. Therefore, we recommend against the use of stormwater infiltration systems at the site, unless additional work is completed to better delineate the extent of and volumetric capacity of the sandy layer. The following sections present our specific recommendations for earthworks and structural components of the project. 6.0 STRUCTURAL DESIGN RECOMMENDATIONS 6.1 General Based on the results of our investigation, it is our opinion the proposed structures can be supported on conventional spread footings constructed in accordance with the recommendations in this report. Additionally, alternative pier foundation design parameters are provided for canopy foundations, if desired. 6.2 Building Foundation Support Recommendations 6.2.1 Dimensions and Design Parameters Continuous wall and isolated spread footings should be at least 12 and 16 inches wide, respectively. The bottom of exterior footings should be at least 16 inches below the lowest adjacent exterior grade. "` Interior footings should be embedded at least 12 inches below the adjacent grade (e.g., base of slab). Footings should be designed to resist an allowable bearing pressure of 1,800 pounds per square foot(psf). The above bearing capacity value represents a net bearing pressure;the weight of the footings and overlying backfill can be ignored in calculating footing sizes. The recommended allowable bearing Mit pressure applies to the total of dead plus long-term live loads and may be increased by one-third for short-term wind and seismic loads. Lateral loads on footings can be resisted by passive earth pressures on the sides of footings and by friction on the bearing surfaces. We recommend that passive earth pressures be calculated using an equivalent fluid weight of 300 pounds per cubic foot(pcf). We recommend using a friction coefficient of 0.35 for footings bearing on native soils, or 0.45 for footings bearing on a minimum 6-inch thick gravel pad. The passive earth pressure and friction components may be combined, provided that the ots passive component does not exceed two-thirds of the total. The lateral resistance values do not include safety factors. /t 15927-12 I4J RTCRQH/$[R September 11,2017 8 Jacksons Store#530 6.2.2 Settlement We estimate that total post-construction settlements should be less than 1 inch, with differential settlement of less than 1/2 inch. 6.2.3 Foundation Subgrade Preparation Prior to the placement of reinforcing steel in footing excavations, all loose,soft or disturbed soils should be removed. The near surface soils consist of generally medium stiff silt and loose silty sand. However,there may be some localized soft soils that need to be overexcavated prior to placement of reinforcing steel. If removal of soft soil is required,the resulting excavation should be backfilled with crushed rock that is compacted to a minimum of 90 percent of its maximum dry density, as determined by American Society for Testing and Materials (ASTM) D 1557. We recommend that Hart Crowser observe all foundation excavations before placement of reinforcing steel or forms to determine that bearing surfaces have been adequately prepared and that the soil conditions are consistent with those observed during our explorations. 6.3 Canopy Foundation Support Recommendations 6.3.1 General The fueling canopy can be supported by conventional spread footing foundations, as described previously. However,we understand that drilled shaft foundations may also be considered to support the canopy structure. We understand that typical design axial downward loads for the canopy structure are approximately 25 kips per column, but that uplift forces generally control design. Drilled shaft foundations are typically 4 to 5 feet in diameter and generally 5 to 8 feet deep, depending upon soil conditions and design loads. 6.3.2 Axial Capacity The load-carrying capacity for shallow shaft foundations will be achieved by side friction in the medium stiff silt and loose silty sand that underlies the site. An allowable skin friction of 250 psf may be assumed for resistance to axial loads. The upper 2 feet of the shaft should be ignored for both uplift and downward loads. Uplift forces can also be resisted by the weight of the shafts. The full weight of the shafts can be used in uplift calculations without application of a safety factor. However, an appropriate safety factor should be applied to the frictional component. 6.3.3 Lateral Resistance Lateral loads on shafts can be resisted by passive earth pressures on the sides of shafts. We recommend that passive earth pressures be calculated using an equivalent fluid unit weight of 300 pcf. The passive resistance for individual shafts can be applied over two projected shaft diameters. We recommend that the upper 2 feet of the shaft be ignored for passive resistance. The passive resistance value does not have a factor of safety applied. 171 15927-11 September 12,2017 /4/Ur OWSB? »3, 4,40 Jacksons Store#530 9 { 6.3.4 Settlement Shafts designed and constructed as recommended are expected to experience static settlements of less than 1 inch. Differential settlements of up to one-half of the total settlement magnitude can be expected between adjacent shafts supporting comparable loads. 6.3.5 Construction Considerations The sandy soils that were encountered at the site will have a moderate potential for caving during shaft installation. Also, while only localized pockets of water were observed in our borings, it is possible that perched groundwater will be encountered during shaft installation. If the contractor encounters caving or groundwater during shaft excavation,then immediate measures to prevent caving and softening of the base of the shaft should be taken. Such measures may include installation of casing, placement of stabilization rock in the base of the shaft, etc. We note that hard bedrock is present at the site at depths ranging from approximately 5 to 20 feet bgs, as noted on Figure 2. If bedrock is encountered during shaft installation, it is likely that refusal to drilling will occur. The shafts will need to be re-evaluated for uplift and overturning resistance if they are prematurely terminated. 6.4 Seismic Design We obtained the design parameters for the design spectral acceleration from the U.S. Seismic Design Maps (USGS 2014)at Latitude 45.4142°and Longitude-122.7925 °.The parameters provided in Table 1 are appropriate for OSSC-based seismic design. Table 1 - Seismic Design Parameters Parameter Value Risk-Targeted MCER Spectral Response Acceleration(Short Period),Ss 0.958 Risk-Targeted MCER Spectral Response Acceleration(1-Second Period), Si 0.420 ime MCEG Peak Ground Acceleration(0-second Period), PGA 0.420 Site Class C Site Coefficient, Fa 1.017 Site Coefficient, F8 1.380 Site Coefficient, Fpga 1.0 ""' Spectral Response Acceleration(Short Period), SDS 0.649 Spectral Response Acceleration(1-Second Period), Sol 0.386 Maximum Considered Earthquake Geometric Mean PGA, PGAM 0.420 .;,10 aw 15927-12 HJIRTOIQ$/,SER September 11,2017 10 Jacksons Store#530 6.5 Floor Slabs Satisfactory subgrade support for concrete slabs supporting up to 125 psf areal loading can be obtained from the new structural fill or native subgrade prepared in accordance with the previous recommendations presented in this report. A minimum 6-inch-thick layer of aggregate base should be placed over the prepared subgrade to assist as a capillary break. Aggregate base material placed directly below the slab should be 3/4-to 1-inch maximum size and per Section 9.4-Structural Fill and Backfill of this report. Slabs should be reinforced according to their proposed use and per the structural engineer's recommendations. Load-bearing concrete slabs may be designed assuming a modulus of subgrade reaction, k, of 125 pounds per square inch per inch, provided the site is prepared as recommended in this report. Flooring manufacturers often require vapor barriers to protect flooring and flooring adhesives. Many flooring manufacturers will warrant their product only if a vapor barrier is installed according to their recommendations. Selection and design of an appropriate vapor barrier, if needed, should be based on discussions among members of the design team. We recommend that Hart Crowser observe slab subgrade preparation before placement of aggregate base. 7.0 DRAINAGE DESIGN RECOMMENDATIONS 7.1 Temporary Drainage During demolition, stripping, and mass grading at the site,the contractor should be made responsible for temporary drainage of surface water as necessary to prevent standing water and/or erosion at the working surface. During rough and finished grading of the building site,the contractor should keep all footing excavations and building pads free of water. 7.2 Surface Drainage The finished ground surface around the buildings should be sloped away from the foundations at a minimum 2 percent gradient for a distance of at least 5 feet. Downspouts or roof scuppers should discharge into a storm drain system that carries the collected water to an appropriate stormwater system. Trapped planter areas should not be created adjacent to the building, and care should be taken to ensure water run off or discharge is not allowed near footings where moisture content fluctuations could result in movement of footings from soil expansion and contraction. 15927-11 La September 12,2017CROWSB+t Jacksons Store#530 11 7.3 Subsurface Drainage Based on our findings, it does not appear that subsurface drainage (e.g.,footing drains)will be required around the building perimeters. However, if trapped planters or adverse grades are created adjacent to buildings,then the use of footing drains should be considered. The need for perimeter footing drains should be evaluated once the grading plan has been developed. 7.4 Infiltration Systems We conducted infiltration testing in general accordance with the City Stormwater Management Manual (Portland 2016)at depths ranging from 2 to 3.3 feet bgs. Two tests had results of —0 inches/hour,while one test had an unfactored rate of 6 inches/hour. The test that had a nonzero infiltration rate was conducted in a sandy soil layer. It is unknown if the sandy layer is laterally continuous,although it is underlain by impermeable silt and bedrock,which may tend to perch water. Therefore, we recommend against the use of stormwater infiltration systems at the site, unless additional work is completed to better delineate the extent of and volumetric capacity of the sandy layer. 8.0 PAVEMENT DESIGN RECOMMENDATIONS 8.1 General Our pavement design recommendations include options for flexible asphaltic concrete (AC) and rigid Portland cement concrete (PCC). Our design thicknesses assume that new pavements will be supported by new or existing structural fill placed and compacted per Section 9.0-Earthworks Recommendations of this report. 8.2 Assumptions and Design Parameters We made the following assumptions regarding, and used the following parameters for,the design of the pavement. • Approximately 1,500 vehicles will visit the site per day • A 20-year design life of approximately 65,000 equivalent single-axle loads (ESALs) (This ESAL represents approximately 5 to 6 delivery trucks per day, 1 fuel tanker per day, and approximately 1,500 automobiles per day. If the actual traffic is different,we should be informed to update our '"' pavement design.) • A resilient modulus of 5,000 pounds per square inch (psi)was assumed for a subgrade that has been moisture conditioned and prepared in conformance with Section 9.0-Earthwork Recommendations of this report • A resilient modulus of 20,000 psi was estimated for the base rock NW AA 15927-12 H I_RTCROUVSER September 11,2017 ur AIM 12 Jacksons Store#530 • Initial and terminal serviceability indices of 4.2 and 2.5, respectively • Reliability and standard deviation of 85 percent and 0.45, respectively • Structural coefficients of 0.42 and 0.13 for the AC and base rock layers, respectively ■ Minimum moduli of rupture and elasticity of 570 and 3,600,000 psi, respectively, for conventional PCC • Minimum compressive strength of 4,000 psi for conventional PCC If these assumptions appear incorrect,then we should be contacted to re-evaluate our recommendations. Also, construction traffic should be limited to non-building, unpaved portions of the site or haul roads. Construction traffic should not be allowed on new pavements. If construction traffic is to be allowed on newly constructed road sections, an allowance for additional traffic will need to be made in the {itei design pavement section. 8.3 Pavement Sections The existing pavement section encountered in our borings consisted of 6 inches of AC over 12 to 18 inches of aggregate base. We recommend maintaining the same AC thickness for new pavements in trafficked areas. In new parking areas,thinner AC thicknesses can be used. The AC pavement sections in Table 2 are minimum recommended material thicknesses. Table 2 — AC Pavement Sections AC Thickness Aggregate Base Thickness Traffic Basis (inches) (inches) Existing New Drive Aisles 6.0 8+ 4.0 Parking Stalls 3.0 8+ 7.0 In areas where at least 8 inches of existing aggregate base remains, no new aggregate base is required. Where 8 inches or less of existing aggregate base is present,then additional new aggregate base should be installed to the minimum thickness listed in Table 2. "'°' The PCC pavement sections in Table 3 include both reinforced and unreinforced sections and are valid for all of the traffic levels. The unreinforced PCC pavement would most typically be used in areas that receive "pass through"traffic, such as decorative crosswalks, etc.;whereas,the reinforced PCC pavement would typically be used as areas with extensive vehicular braking and increased long-term performance requirements, such as at the fueling stations. 15927-11 Sit September 12,2017 HIIRTCROWSER -ur+ Jacksons Store#530 13 Table 3 — PCC Pavement Sections PCC Thickness Aggregate Base Thickness +s� PCC Pavement Type (new or existing) (inches) (inches) Unreinforced 5.0 6.0 Reinforced 6.0 6.0 8.4 Pavement Materials 8.4.1 Flexible AC Jai The AC should be Level 2, 12.5-mm, dense hot mix asphalt concrete (HMAC) according to Oregon Standard Specifications for Construction (OSS) 00744—Minor Hot Mixed Asphalt Concrete Pavement. The asphalt cement binder should be PG 64-22 Performance Grade Asphalt Cement. The minimum AC lift thicknesses should be 1.5 inches. The AC should be compacted to 91 percent of Rice Density of the mix,as determined in accordance with ASTM D 2041. 8.4.2 Rigid PCC Rigid PCC used for pavement should meet the specifications provided in OSS 00756—Plain Concrete e3i" Pavement. The installed concrete should be Class 4000 1.5-inch paving concrete per OSS 02001— Concrete. The PCC joints should have a maximum spacing of 12 feet and be constructed in accordance with OSS 00756.48—Joints. Unreinforced PCC shall be interlocked at contraction joints (e.g., continuous slab with no dowels),though dowels should be used at construction and expansion joints. Reinforced PCC should have#4 bars at 24 inches on center, each way at the mid-depth of the PCC. 8.4.3 Aggregate Base Imported granular material used as base aggregate (base rock) should meet the criteria specified in Section 9.4-Structural Fill and Backfill of this report. The base aggregate should be compacted to not less than 95 percent of the maximum dry density,as determined by ASTM D 1557. We recommend placement of a geotextile separation fabric beneath the aggregate base, if the base is placed on native soils. :fps If the existing base rock that blankets the site is documented to be free of debris and other deleterious materials and is of sufficient thickness after site grading(at least 8 inches),the existing rock may be used to support to new pavement. If sufficient rock thickness is not present,then if grades allow, additional rock can be placed atop the existing rock,otherwise the existing rock will need to be removed and new rock placed. r� 15927-12 H RTCROWSEf' September 11,2017 lira 14 Jacksons Store#530 9.0 EARTHWORKS RECOMMENDATIONS 9.1 General ,tilt Based on available information,we estimate the mass grading for the site will be minimal with cuts and fills on the order of 0 to 2 feet deep/thick. However, deeper excavations may be required for installation of utilities. All earthwork activities should be conducted in accordance with the City's Standard Construction Specifications (SCS) (Portland 2010), in particular section SCS 00330—Earthwork, and the OSS (ODOT 2015), including OSS 00330—Earthwork, OSS 00400—Drainage and Sewers, and OSS 02600— Aggregates, depending on the application. 9.2 Site Preparation 9.2.1 Demolition Demolition should include complete removal of existing site improvements within areas to receive itok new pavements, buildings, or engineered fill. Underground utility lines encountered in areas of new improvements should be completely removed or grouted full if left in place. t Voids resulting from removal of any improvements or loose soil in utility lines should be backfilled with compacted structural fill, as discussed in Section 9.4-Structural Fill and Backfill of this report. The 4444 bases of such excavations should be completed to a firm subgrade before filling, and their sides sloped at a minimum of 1 horizontal to 1/2 vertical (1H:1/2V)gradient to allow for more uniform compaction at the edges of the excavations. ,tom Materials generated during demolition of existing improvements should be transported off site for disposal or stockpiled in areas designated by the owner. In general, these materials will not be suitable for reuse as engineered fill. However, asphalt(AC), concrete, and base rock materials may be crushed and recycled for use as general fill. Such recycled materials should meet the specifications for imported granular material, as described in Section 9.4-Structural Fill and Backfill of this report. t�ltF 9.2.2 Stripping The majority of the site is covered by AC surfacing with some landscaping and scattered trees around the perimeter of the lot. We anticipate that stripping of organic materials will be minimal. However, we note a few trees on the south side of the property that may encroach on the proposed building °` addition. If these trees are removed, the root balls should be grubbed out to the depth of the roots up to approximately 1 inch in diameter, which could exceed 3 feet bgs. Depending upon the methods used to remove the root balls, considerable disturbance and loosening of the subgrade could occur. ttth We recommend that soil disturbed during grubbing operations be removed to expose firm, undisturbed subgrade. The resulting excavations should be backfilled with compacted structural fill, as 4+11 described in Section 9.4-Structural Fill and Backfill of this report. sM 15927-11 Sta September 12,2017OR0WSER !tom Jacksons Store#530 15 The actual stripping depth should be based on field observations at the time of construction. Stripped material should be transported off site for disposal or stockpiled for later use in new landscaped areas. 9.2.3 Subgrade Preparation and Evaluation Following demolition, site preparation, and rough grading,the suitability of the subgrade should be evaluated by proof rolling with a fully loaded dump truck or similar heavy rubber-tired construction equipment to identify any remaining soft, loose, or unsuitable areas. The proof roll should be conducted prior to placing fill. In confined areas or if wet soils are present,the subgrade evaluation can be done by probing with a steel foundation probe. Observations and probing should be performed by Hart Crowser. Wet soil that has been disturbed due to site preparation activities, or soft or loose zones identified during proof rolling or probing, should be recompacted in place, if practical,or removed and replaced with compacted structural fill. All subgrades should be in a dense, non-yielding condition prior to new fill, slab-on-grade,or pavement section placement. If site preparation activities cause excessive subgrade disturbance, replacement with imported structural fill may be necessary. Disturbance to the native subgrade should be expected if site preparation and earthwork are conducted during periods of excessive wet weather and/or when the moisture content of the surficial soil exceeds optimum. 9.2.4 Wet Soil/Wet Weather Construction The existing site soils are generally fine-grained and medium stiff to soft, and therefore, are potentially "ii° susceptible to disturbance e.p ( g., pumping and rutting)when wet. However, most of the site is covered with asphalt pavements or slabs that, if left in place, have a low susceptibility to disturbance. 'Stir The contractor should be responsible to protect the native or excavated subgrade from trafficking during periods of wet weather or when the moisture content of the material is more than a few percentage points above optimum. The contractor should also be responsible for protecting or repairing the subgrade from construction-related damage. We recommend that wherever possible the existing asphalt and/or base rock be left in place during construction,so that equipment does not traffic directly on the native soils. 9.3 Excavation """' 9.3.1 General Site soils within expected excavation depths are generally soft to medium stiff silts or loose silty sands. However, dense bedrock is present as shallow as approximately 5 feet below grade, as shown on Figure 2. It is our opinion that conventional earthmoving equipment in proper working condition should be capable of making necessary general excavations for utilities,footings, and other earthwork. Excavations into these materials should be possible with conventional earthwork equipment,though localized difficult excavation may occur when bedrock is encountered. If excavations into rock are required then rock hammers, blasting, or other similar measures may be required. The earthwork contractor should be responsible for providing equipment and following procedures as needed to excavate the site soils and rock(if needed) as described in this report. I4444 IW " 15927-12 HARTCROWSER September 11,2017 16 Jacksons Store#530 9.3.2 Excavation Stability All excavations should be made in accordance with applicable Occupational Safety and Health Administration (OSHA)and state regulations. Site soils are generally OSHA Type B or C. Excavations that extend below the groundwater table will encounter unstable sidewalls and bases that may slough, run, cave, or heave and become unstable if not dewatered and properly shored. Because of the variables involved,actual slope angles required for stability in temporary cut areas can only be estimated before construction. We recommend that stability of the temporary slopes used for construction be the responsibility of the contractor, since the contractor is in control of the construction operation and is continuously at the site to observe the nature and condition of the subsurface. All temporary soil cuts associated with site excavations(greater than 4 feet in depth)should be adequately sloped back to prevent sloughing and collapse in accordance with OSHA guidelines. The stability and safety of cut slopes depend on a number of factors, including: • The type and density of the soil; • The presence and amount of any seepage; • Depth of cut; • Proximity and magnitude of the cut to any surcharge loads,such as stockpiled material,traffic loads, or structures; • Duration of the open excavation; and • Care and methods used by the contractor. If groundwater seepage is encountered within the excavation slopes,the cut slope inclination may have to be flatter than 1.5H:1V. However, appropriate inclinations will ultimately depend on the actual soil and groundwater seepage conditions exposed in the cuts at the time of construction. It is the responsibility of the contractor to ensure that the excavation is properly sloped or braced for worker protection, in accordance with OSHA guidelines. To assist with this effort,for planning purposes only,we make the following recommendations regarding temporary excavation slopes. • Protect the slope from erosion with plastic sheeting for the duration of the excavation to minimize surface erosion and raveling. • Limit the maximum duration of the open excavation to the shortest time period practicable. • Place no surcharge loads (equipment, materials, etc.)within 10 feet of the top of the slope. More restrictive requirements may apply depending on specific site conditions,which should be continuously assessed by the contractor. If temporary sloping is not feasible based on site spatial constraints, excavations could be supported by internally braced shoring systems,such as a trench box or other temporary shoring. There are a variety of options available. We recommend that the contractor be responsible for selecting the type of shoring system to apply. A 15927-11 1.1 September 12,2017 HARTCROWSER Jacksons Store#530 17 9.3.3 Dewatering Significant groundwater seepage was not encountered during our explorations; however,some water was present at approximately 8 feet bgs, and the presence of groundwater may be seasonal, particularly if precipitation perches on or within the silty soils or atop the bedrock. Construction of utilities and other improvements that extend below groundwater levels will require dewatering and shoring programs capable of adapting to varied soil and groundwater conditions. The contractor should be prepared to provide shoring and dewatering systems that are capable of such conditions. In addition to safety considerations, running soil, caving, or other loss of ground will increase backfill volumes and can result in damage to adjacent structures or utilities. We anticipate that sump pumps will be sufficient to remove groundwater encountered in most excavations. Although pumping from sumps may be effective in removing water from the bases of trenches, it will not prevent or reduce the greater risk of trench wall caving and sloughing caused by seepage. 9.4 Structural Fill and Backfill “ Structural fill should be considered to include subgrade soils beneath buildings,foundations, slabs, pavements, and other areas intended to support structures or within the influence zone of structures. Fill should only be placed over a subgrade that has been prepared in conformance with the prior sections of this report. A variety of material may be used as structural fill at the site. However, all material used as structural fill should be free of organic matter or other unsuitable materials and should meet specifications provided in the OSS for structural fill. A brief characterization of some of the acceptable materials and our recommendations for their use as structural fill are provided below. 9.4.1 On-Site Soils On-site, near-surface soils that could be excavated and used for on-site fill are generally silts and silty sands. We anticipate that these soils may be too moist to use as structural fill, unless significant drying is conducted. If used,the native soils should be properly moisture conditioned;free of debris, organic materials,and particles over 6 inches in diameter; and meet the specifications provided in OSS 00330.12—Borrow Material. The material should be placed and compacted in lifts with maximum uncompacted thicknesses and relative densities as recommended in the tables that follow. 9.4.2 Imported Select Structural Fill Imported granular material used as structural fill should be pit or quarry run rock, crushed rock, or crushed gravel and sand and should meet the specifications provided in OSS 00330.14—Selected Granular Backfill or OSS 00330.15—Selected Stone Backfill. The imported granular material should also be angular,fairly well graded between coarse and fine material, have less than 5 percent by dry weight passing the U.S. Standard No. 200 Sieve, and have at least two mechanically fractured faces. The material should be placed and compacted in lifts with maximum uncompacted thicknesses and relative densities as recommended in the tables that follow. NV &X 15927-12 H/yq'j'(, QH SER September 11,2017 18 ( Jacksons Store#530 If the imported granular fill is placed atop soft zones of silt,the soft materials should be removed and/or separation fabric should be placed atop the silt subgrade prior to the placement of the imported granular material. The geotextile should meet the specifications provided in OSS 02320.20— '«' Geotextile Property Values for soil separation. The geotextile should be installed in conformance with the specifications provided in OSS 00350—Geosynthetic Installation. 9.4.3 Aggregate Base Imported granular material used as aggregate base (base rock) beneath pavements,the building, or footing alignments should be clean, crushed rock or crushed gravel and sand that is fairly well graded between coarse and fine. The base aggregate should meet the specifications of OSS 00641— Aggregate Subbase, Base, and Shoulders Base Aggregate, depending upon application,with the exception that the aggregate must have less than 5 percent by dry weight passing a U.S.Standard No. 200 Sieve and have at least two mechanically fractured faces. ram« For use beneath pavements or footings,the aggregate base should have a maximum particle size of 1 inch or 1.5 inches,while for use beneath the building or sidewalk slabs should have a maximum particle size of 0.75 or 1 inch. For use beneath buildings,the base rock should also meet the gradation of OSS 2630.11—Open-Graded Aggregate. The aggregate base material should be placed and compacted in lifts with maximum uncompacted thicknesses and relative densities as recommended in the tables that follow. 9.4.4 Trench Backfill Trench backfill placed beneath, adjacent to, and for at least 12 inches above utility lines (i.e.,the pipe zone) should consist of well-graded granular material with a maximum particle size of 1 inch and should meet the specifications of OSS 00405.13—Pipe Zone Material and the pipe manufacturer's requirements. data Within pavement and slab subgrades the remainder of the trench backfill up to the subgrade elevation can consist of the above 1-inch material or of granular material with a maximum particle size of 3 inches, have less than 10 percent by dry weight passing the U.S. Standard No. 200 Sieve, and meet the specifications of OSS 00405.14—Class B, C, or D Trench Backfill, as appropriate. In landscape areas,trench backfill placed above the pipe zone may consist of general fill materials that are free of organics and materials over 3 inches in diameter and meet the specifications provided in OSS 00405.14—Class A, B,C,or D Trench Backfill, as appropriate. The material should be placed and compacted in lifts with maximum uncompacted thicknesses and relative densities as recommended in the tables that follow. a 15927-11 ILI September 12,2017 HARTCROWSER Jacksons Store#530 119 9.4.5 Stabilization Materials If imported granular material is used to create haul roads for construction traffic or is required for stabilization of the bases of excavations,we recommend that material consist of pit or quarry run rock, or crushed rock. The material should generally be sized between 2 and 6 inches, have less than 5 percent by dry weight passing the U.S.Standard No.4 Sieve, and have at least two mechanically fractured faces. The material should be free of organic matter and other deleterious material. The material should also meet the specifications of OSS 00330.16—Stone Embankment Material. Stabilization material should be placed in lifts between 12 and 18 inches thick and be compacted to a well-keyed condition with appropriate compaction equipment without using vibratory action. In trench excavations,a walk behind sheepsfoot roller or a pinwheel on an excavator typically can provide adequate compaction if carefully used. If groundwater or an unstable subgrade is present and "quarry spalls"or similar open-graded rocks are used for stabilization of the base of excavations or access roadways,then a layer of separation fabric should be placed atop the stabilization material prior to the placement of the pipe bedding material. ;ti„ The geotextile should meet the specifications provided in OSS 02320.20—Geotextile Property Values for soil separation. The geotextile should be installed in conformance with the specifications provided in OSS 00350—Geosynthetic Installation. 9.4.6 Recycled Materials PCC,AC,and base rock rubble may be used as structural fill, provided there is no contamination and that the recommendations below are followed. 9.4.6.1 Processed Fill Materials 4,0 Recycled material may be used as select structural fill, provided it is processed by crushing and screening,grinding in place,or other methods to meet the structural fill recommendations in this report. This recycled fill may be used as structural fill, except as base rock,for pavements or buildings or within utility trenches(unless approved by the pipe manufacturer). ran 9.4.6.2 Unprocessed Fill Materials PCC and AC rubble,which has a maximum particle size of 4 inches in nominal diameter, may be mixed with other imported or on-site fill to create a uniform,well-graded material and used in pavement tes areas. We recommend that at least 1 foot of other processed or imported structural fill overlie the unprocessed fill material blend. 11Yi 6Wi v 15927-12 HA.RTCROWSEFt September 11,2017 wr 20 Jacksons Store#530 9.5 Fill Placement and Compaction Structural fill should be placed and compacted in accordance with the following guidelines. • Place fill and backfill on a prepared subgrade that consists of firm, inorganic native soils or approved structural fill. • Place fill or backfill in uniform horizontal lifts with a thickness appropriate for the material type and compaction equipment. Table 4 provides general guidance for lift thicknesses. Table 4 — Guidelines for Uncompacted Litt Thickness Guidelines for Uncompacted Lift Thickness Compaction (inches) Equipment Fine-Grained Granular and Crushed Crushed Rock Soil Rock(Maximum Particle (Maximum Particle Size Size < 11/2 inch) > 1'/ inch) Plate Compactors and Jumping Jacks 4—8 4—8 Not Recommended Rubber-Tire Equipment 6—8 10—12 6—8 Light Roller 8—10 10—12 8—10 Heavy Roller 10—12 12—18 12—16 'N Hoe Pack Equipment 12—16 18—24 12—16 Note: The above table is based on our experience and is intended to serve as a guideline.The information provided in this table should not be included in the project specifications. • Use appropriate operating procedures to attain uniform coverage of the area being compacted. • Place fill at a moisture content within about 3 percent of optimum as determined in accordance with ASTM Test Method D 1557. Moisture condition fill soil to achieve uniform moisture content within the specified range before compacting. Compact fill to the percent of maximum dry densities as noted in Table 5. • Do not place,spread, or compact fill soils during freezing or unfavorable weather conditions. Frozen or disturbed lifts should be removed or properly recompacted prior to placement of subsequent lifts of fill soils. tilli atilt NW 15927-11 September 12,2017 H/1RTMO$J$,'f Jacksons Store#530 21 Table 5 — Fill Compaction Criteria Percent of Maximum Dry Density Fill Type Determined in Accordance with ASTM D 1557 0—2 Feet Below >2 Feet Below Pipe Bedding and Subgrade Subgrade Pipe Zone Mass Fill 92 92 (fine-grained soils) Mass Fill 95 90 (granular material) Aggregate Base 95 95 Trench Backfill 95 92 90 Nonstructural Trench Backfill 90 88 Nonstructural Zones 90 88 90 Note: The above table is based on our experience and is intended to serve as a guideline. The information provided in this table should not be included in the project specifications. During structural fill placement and compaction, a sufficient number of in-place density tests should be completed by Hart Crowser to verify that the specified degree of compaction is being achieved. For structural fill with more than 30 percent retained on the 3/4-inch sieve, Hart Crowser should visually verify proper compaction with a proof roll or other methods. 10.0 CONSTRUCTION OBSERVATIONS Satisfactory foundation and earthwork performance depends to a large degree on quality of construction. Sufficient monitoring of the contractor's activities is a key part of determining that the work is completed in accordance with the construction drawings and specifications. Subsurface conditions observed during construction should be compared with those encountered during subsurface explorations. Recognition of changed conditions often requires experience;therefore, Hart Crowser or their representative should visit the site with sufficient frequency to detect whether subsurface conditions change significantly from those anticipated. We recommend that Hart Crowser be retained to monitor construction at the site to confirm that subsurface conditions are consistent with the site explorations and that the intent of project plans and specifications relating to earthwork and foundation construction are being met. In particular,we recommend that the foundation, slab-on-grade, and pavement subgrades and compaction of structural fill and aggregate base be observed and/or tested by Hart Crowser. 15927-12 HARTJ?QNUSC-R September 11,2017 22 I Jacksons Store#530 11.0 LIMITATIONS We have prepared this report for the exclusive use of PacWest Energy and their authorized agents for the proposed building addition and site improvements at 11290 SW Bull Mountain Road in Tigard, Oregon, in accordance with our May 30, 2017 proposal. Our report is intended to provide our opinion of geotechnical parameters for design and construction of the proposed project based on exploration locations that are believed to be representative of site conditions. However, conditions can vary significantly between exploration locations and our conclusions should not be construed as a warranty or guarantee of subsurface conditions or future site performance. Within the limitations of scope, schedule, and budget,our services have been executed in accordance with generally accepted practices in the field of geotechnical engineering in this area at the time this report was prepared. No warranty, express or implied, should be understood. Any electronic form,facsimile, or hard copy of the original document (email,text,table, and/or figure), if provided, and any attachments are only a copy of the original document.The original document is stored by Hart Crowser and will serve as the official document of record. 12.0 REFERENCES ASCE/SEI 2010. Minimum Design Loads for Buildings and Other Structures,ASCE 7-10,American Society of Civil Engineers(ASCE)-Structural Engineering Institute (SEI), 2010. Beeson, M.H.,T.L Tolan, and I.P. Madin 1989. Geologic map of the Beaverton Quadrangle, Washington county, Oregon: Oregon Department of Geology and Mineral Industries, Geological Map Series 59, scale 1:24,000 Delta Environmental Consultants 2007. Phase II Environmental Site Assessment, Shell Oil Products US, SAP#121713, 5524 SE 82nd Avenue, Portland, Oregon, dated October 15, 2007. Green, G.L. 1983. Soil Survey of Multnomah County, Oregon: U.S. Department of Agriculture Soil Conservation Service. HAZVU 2017. Hazard Viewer online portal, 2017. International Code Council (ICC) 2015. 2015 International Building Code(IBC). ICC 2014. 2014 Oregon Structural Specialty Code(OSSC). Mabey, M., I.P. Madin, G. Black, D. Meier,T,.L.Youd, C.Jones, C., and B. Rice 1997. Relative Earthquake Hazard for the Gladstone Quadrangle, Clackamas and Multnomah Counties, Oregon. Oregon Department of Geology and Mineral Industries Interpretive Map Series IMS-1, 1 pl., 1:62,500 scale. ea 15927-11 September 12,2017inVOw5 41111 Jacksons Store#530 123 Occupational Safety and Health Administration (OSHA)Technical Manual Section V: Chapter 2, Excavations: Hazard Recognition in Trenching and Shoring: http://www.osha.gov/dts/osta/otm/otm v/otm v 2.html - Oregon State Department of Transportation(ODOT)2015.Oregon Standard Specifications for Construction (OSS). Oregon Water Resources Department(OWRD)2017.Online Well Log Query, http://apps.wrd.state.or.us/a pps/gw/well log/ Personius,S.F.,compiler, 2002.Quaternary Fault and Fold Database of the United States, U.S. wr Geological Survey website: http://earthquakes.usgs.gov/regional/gfaults Portland 2016. Stormwater Management Manual,Chapter 2.3.6—Infiltration and Soil Requirements. https://www.portlandoregon.gov/bes/ Portland 2010. Standard Construction Specifications, City of Portland, Oregon, October 1,2010. Snyder, D.T.2008. Estimated Depth to Ground Water and Configuration of the Water Table in the Portland, Oregon Area: U.S.Geological Survey Scientific Investigations Report 2008-5059,accessed online at http://pubs.usgs.gov/sir/2008/5059/ U.S. Department of Agriculture(USDA)2006. USDA Web Soil Survey,2006, tags http://websoilsurvev.sc.egov.usda.gov/ U.S. Geologic Survey(USGS)2014. National Seismic Hazard Mapping Project—U.S. Seismic Design Maps website: http://earthquake.usgs.gov/designmaps/us/application.php USGS 2013. Geologic Hazards Science Center—2008 Interactive Deaggregations website: http://geohazards.usgs.gov/deaggint/2008/ USGS 2006. Quaternary Fault and Fold Database of the United States,from USGS website: Wig http//:earthquake.usgs.gov/regional/qfaults/ Walker,G.W.and N.S. McLeod 1991. Geologic Map of Oregon, U.S. Department of the Interior and U.S.Geological Survey. 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CD Y. t,' ki 4'''''''''''' 1, $ 0 'i .7 4,: ,-, -,. it ,r) c ,,,,,„,,,,,ra or O i * 15, Cn f i 2 my giryi...46 E ; O sw ftw000s. tt,,,, f r. .,:::-...n..pi,' G O i ''`Vt'' ,os , ,/, °, 4 fo .t''''1 w,!.4W Wows,SI 4 ,I .„ t1 il, •:., 4 'SOY,,,, 4 W N- Z : 2 Sources: Esri, HERE, DeLorme, USGS, Intermap,INCREMENT P, NRCan,Esri Japan, METI, Esri China = — -0; (Hong Kong),Esri Korea, Esri (Thailand), Mapmylndia, NGCC,©OpenStreetMap contributors,and the GIS ,e ... 0 0 .0 O Jackson Food Stores#530-SW Bull Mountain Road '6 z Tigard, Oregon -c-. 76 Q Vicinity Map -,- N 'F'ts 15927-12 9/17 0 1,000 2,000 4,000 E...f, 111101111.1111111111111.19 Feet arm Figure ILI 0 O 1 o iiillitTO?OWSER MI ,tall / ,. ... • - ";. ......a... ..i ll i (°. ' "`,' ''' ..."!,,....7°• ' '""''''''"'"''.' ' .','B4 , il.J z/V:e K) el.) DS-SB#6 DS'S B#7 iN . DS,-S-B#5 , _ ' . .. . ,, ,, 1, DS-SB#8 \ NI. 9 1 '''' _ t• 1 .*.r' B-20 I ‘ % 8.4 1 DS-SB#4 : . 13 , .• / ;... , DS-SB#3 / DS-SB#1 12 5i25,," I iik 1 ,i t DS-SB#2 go ? cs.' ritiP e20 1-3Q tir iti 0 c) - . I -41 ii CI_ (j co 5 , — a--) a is cc . 5 --5 m 6 u-) P2 0 c o o co --'I Source:Esri,DigitalGlobe,GeoEye, Earthstar Geographics,CNES/Airbus DS, USDA, USGS,AeroGRID, IGN,and the GIS User Community N. csi LEGEND ,.0 7-;; 3 • Boring (Hart Crowser, 2017) t Jackson Food Stores#530-SW Bull Mountain Road z Boring (Delta, 2007) Tigard, Oregon Eu * 32 8.4 Depth to Bedrock(feet) L .. 15-- Depth to Hard Bedrock Contour(feet) N Site and Exploration Plan 15927-11 9/17 Q_ 0 25 50 100 NW Figure c) minommem.11.1111 Feet II/ 0 0 Note: Feature locations are approximate. HARTCROVVSB? 2 a eYYI eeYl APPENDIX A Field Explorations tilii tithi Mit 15927-11 HART(, September 12,2017 wr APPENDIX A Field Explorations General We evaluated subsurface soil and groundwater conditions at the site by advancing five drilled borings and conducting infiltration tests in three drilled borings on July 5, 2017. The drilled borings were advanced by a trailer-mounted Big Beaver drill rig using solid-stem auger techniques and operated by Dan Fischer Excavating of Banks, Oregon. The locations of the explorations are shown on Figure 2 of the report. The exploration locations were approximately located by taping from existing mapped features. Exploration locations should be considered accurate only to the degree implied by the methods used. The field explorations were coordinated by our geotechnical staff who located the explorations, classified the various soil units encountered, obtained representative soil samples for geotechnical testing, observed and recorded groundwater conditions, and maintained a detailed log of each boring and infiltration test. Exploration logs are included in this appendix. Soil Sampling and Classification Materials encountered in the borings were classified in the field in general accordance with ASTM Standard Practice D 2488 "Standard Practice for the Classification of Soils(Visual-Manual Procedure)." Soil classifications and sampling intervals are shown on the exploration logs in this appendix. Soil samples were obtained from the borings using an SPT sampler was used in general conformance with ASTM Test Method D 1586 "Standard Method for Penetration Test and Split-Barrel Sampling of Soils." The sampler was driven by a 140-pound cathead hammer falling 30 inches. The N-value, or number of blows required to drive the sampler 1 foot or as otherwise indicated into the soils, is shown adjacent to the sample symbols on the boring logs. Disturbed samples were obtained from the sampler for subsequent classification and testing. Infiltration Testing Infiltration testing was conducted using the Encased Falling Head Procedure in general accordance with the City's Stormwater Management Manual (Portland 2016),Chapter 2.3.6, Infiltration and Soil Requirements adjacent borings B-1, B-2, and B-3 to depths between 2 and 3.25 feet. We installed a 6-inch-diameter PVC pipe in an open borehole,filled the pipe with approximately 24 inches of water, and observed the drop in water head over time. At B-1 and B-3, no significant drop in water level was observed over the duration of the test. At B-2, an unfactored infiltration rate of 6 inches/hour was measured. NV 15927-11 HARTGIOWSER September 12,2017 �., .. • Sample Description • Classification of soils in this report is based on visual field and laboratory observations which include density/consistency,moisture condition, grain size,and plasticity estimates and should not be construed to imply field nor laboratory testing unless presented herein.ASTM D 2488 visual-manual identification methods were used as a guide. Major divisions are not necessarily an indicator of soil behavior,which is a function of fines content activity and loading rate. Relative Density/Consistency Minor Constituents Estimated Percentage Soil density/consistency in borings is related primarily to the standard penetration resistance(N). Soil density/consistency in test pits and probes is Trace <5 estimated based on visual observation and is presented parenthetically on Few 5 - 10 the logs. Little 15 - 25 SAND or GRAVEL N SILT or CLAY N Some 30 - 45 Relative Density (Blows/Foot) Consistency (Blows/Foot) Very loose 0 to 4 Very soft 0 to 2 Loose 4 to10 Soft 2 to 4 Medium dense 10 to 30 Medium stiff 4 to 8 Soil Test Symbols Dense 30 to 50 Stiff 8 to 15 Very dense >50 Very stiff 15 to 30 %F Percent Passing No.200 Sieve t> Hard >30 AL Atterberg Limits I • I Water Content in Percent I— Liquid Limit o Moisture Natural z Plastic Limit o Dry Absence of moisture,dusty,dry to the touch iu a Moist Damp but no visible water CA Chemical Analysis o Wet Visible free water, usually soil is below water table CAUC Consolidated Anisotropic Undrained Compression a CAUE Consolidated Anisotropic Undrained Extension it, CBR California Bearing Ratio CIDC Consolidated Drained Isotropic Triaxial Compression r; Soil Classification Chart CIUC Consolidated Isotropic Undrained Compression vs CKODC Consolidated Drained k0 Triaxial Compression Major Divisions Symbols Typical CKODSS Consolidated k0 Undrained Direct Simple Shear z Gra h USCS Descriptions CKOUC Consolidated k0 Undrained Compression •Ni• Well-Graded Gravel; CKOUE Consolidated k0 Undrained Extension Clean •iv OW Well-Graded Gravel with Sand CRSCN Constant Rate of Strain Consolidation n!t w `1 Gravels p DSS Direct Simple Shear a_ (<5%fines) Poorly Graded Gravel; S o Cy GP Poorly Graded Gravel with Sand DT In Situ Density GS Grain Size Classification o Gravel GW-GM Well-Graded Gravel with Silt: HYD Hydrometer o and • Well-Graded Gravel with Silt and Sand ILCN Incremental Load Consolidation „, w Gravelly I Well-Graded Gravel with Clay; KOCN k0 Consolidation w Soils • GW-GC kc Constant Head Permeability S Gravels r Well-Graded Gravel with Clay and Sand More than (10%fines)o kf Falling Head Permeability t- �,� Poorly Graded Gravel with Silt; MD Moisture Density Relationship g 50%of Coarse o GP-GM Poorly Graded Gravel with Silt and Sand t Fraction 1 iiOC Organic Content J Retained on o I'/i OT Tests byOthers st. D Poorly Graded Gravel with Clay: o No.4 Sieve o i r GP-GC Poorly Graded Gravel with Clay and Sand P Pressuremeter r 0 PID Photoionization Detector Reading w GM Silty Gravel. PP Pocket Penetrometer Coarse Gravels with o I ' Silty Gravel with Sand o Grained Fines ► SG Specific Gravity Cl)~ Soils (>12%fines)' GC Clayey Gravel; TRS Torsional Ring Shear ;wa z J� Clayey Gravel with Sand TV Torvane O More than 50% r_�.:: Well-Graded Sand: UC Unconfined Compression Y of Material Sands with r.•..'..•I. SW Well-Graded Sand with Gravel UUC Unconsolidated Undrained Triaxial Compression o Retained on few Fines - VS Vane Shear a No.200 Sieve (<5%fines) •.: sp Poorly Graded Sand: WC Water Content Poorly Graded Sand with Gravel ,z� . rn Sand r�.�• .' SW-SM Well-Graded Sand with Silt `r' and '0 Well-Graded Sand with Silt and Gravel 73. Sand Groundwater Indicators Y Soils ✓ SW-SC Well-Graded Sand with Clay; O Sands ` // Well-Graded Sand with Clay and Gravel ;xe. m More than (10%fines) V Groundwater Level on Date or At Time of Drilling(ATD) w Poorly Graded Sand with Silt;i- 50%of Coarse ' SP-SM Poo Graded Sand with Silt and Gravel l Groundwater Seepage(Test Pits) o Fraction LL Passing No.4 • :/• ��j.� Poorly Graded Sand with Clay; Sieve f� SP-SC Poorly Graded Sand with Clay and Gravel r M ,, Silty sand; Sample Symbols Sands with � SM Silty Sand with Gravel p y Fines . °i (>12%fines)". SC Clayey Sand; �� Cla e Sand with Gravel ® 1.5"I.D.Split Spoon Core Run �� Grab Y Y m ML Silt;Silt with Sand or Gravel: IL 3.0"I.D.Split Spoon 0 Sonic Core I ll l l Cuttings ,,;}. O Sandy or Gravelly Silt Silts rim Modified California m Thin-walled Sampler Q Fine Grained " MH Elastic Silt.Elastic Silt with Sand or Sampler IX Soils ///J��'y', Gravel;Sandy or Gravelly Elastic Silt m_ • More than 50% CL Lean Clay;Lean Clay with Sand or U of Material Clays Gravel;Sandy or Gravelly Lean Clay Well Symbols ,,, Z F Passing No.200 / Fat Clay;Fat Clay with Sand or Monument _:i ':'�•: Sieve , CH Gravel Sandy or Gravelly Fat Clay Surface Seal /'''A *pm, Cu. — Organic Soil;Organic Soil with Sand or Bentonite Seal ' Organics —= OUGH Gravel;Sandy or Gravelly Organic Soil ied / } — Well Casing J rxa Z l y Peat-Decomposing Vegetation- O Highly Organic PT Fibrous to Amorphous Texture Sand Pack oo Well Tip or Slotted Screen 0 Slough .�i o 0 a w V Project: Jackson Food Stores#530-SW Bull Mountain Road Key to Figure A-1 o Location: Tigard,Oregon 'w H1tRTCROI VSL-R Project No.: 15927-11 Exploration Logs Sheet 1 of 1 , Date Started: 7/5/17 Date Completed: 7/5/17 Drilling Contractor/Crew: Dan J.Fischer Excavating,Inc./Greg wr Logged by: K.Smyth Checked by: J.Harmon Drilling Method: Solid Stem Auger Location: N:645,375.87 E:7,613,366.89 Rig Model/Type: Big Beaver/Trailer-mounted drill rig Ground Surface Elevation: 306 feet Hammer Type: Cathead Horizontal Datum: OR State Plane N,NAD 83,ft. Hammer Weight(pounds): 140 Hammer Drop Height(inches): 30 Vertical Datum: NAVD 88 Hammer Efficiency(%):Measured: NA Estimated: 60% Comments: Auger Diameter: 3 inches Casing Diameter: NA Total Depth: 6.5 feet Depth to Ground Water: Not Identified Aiat Sample Data I t g Material we t Description t X Percent Fines r o 3 c' Number m A SPT N Value 1-1-10 m J Tests t7 — 0 10 20 30 40 0- Asphalt(6-inch thick) Base aggregate(18-inch thick) -o - •• Stiff,dry,dark brown,SILT(ML),trace sand. yY• 5 18 - n 11-11 • 5 we Infiltration test conducted at 3.3 feet.See text for additional details. 10 - z Mill o - 5 12 18 • Very dense,dry,brown,SILTY SAND(SM).(Decomposed Basalt) 5 23 a wo _ 24 GS,WC . Vlf `.' 50 / . . 74 m Refusal at 6.5 feet. F- (Due to bedrock.) Q. O - 10— —10 LL N 2 O M W z - 0 YW co z- 0 co 15— —15 aril - m $ �"+ N pCO W 0 Z Z LL N- - U) N- - 20— —20 co N J General Notes: = 1.Refer to Figure A-1 for explanation of descriptions and symbols. 2.Material descriptions and stratum lines are interpretive and actual changes may be gradual. Solid stratum lines indicate distinct contact between material strata or geologic 5 units. Dashed stratum lines indicate gradual or approximate change between material strata or geologic units. c` 3.USCS designations are based on visual-manual identification(ASTM D 2488)unless otherwise supported by laboratory testing(ASTM D 2487). Wr o 4.Groundwater level,if indicated,is at time of drilling/excavation(ATD)or for date specified.Level may vary with time. 2 iial Project: Jackson Food Stores#530-SW Bull Mountain Road Boring Log Figure A 2 o Location: Tigard,Oregon HARTCROtrr = WSER Project No.: 15927-11 B-1 Sheet 1 of 1 Date Started: 7/5/17 Date Completed: 7/5/17 Drilling Contractor/Crew: Dan J.Fischer Excavating,Inc./Greg an Logged by: K.Smyth Checked by: J.Harmon Drilling Method: Solid Stem Auger Location: N:645,471.72 E:7,613,350.68 Rig Model/Type: Big Beaver/Trailer-mounted drill rig Ground Surface Elevation: 308 feet Hammer Type: Cathead Horizontal Datum: OR State Plane N,NAD 83,ft. Hammer Weight(pounds): 140 Hammer Drop Height(inches): 30 'a" Vertical Datum: NAVD 88 Hammer Efficiency(%):Measured: NA Estimated: 60% Comments: Auger Diameter: 3 inches Casing Diameter: NA Total Depth: 8.42 feet Depth to Ground Water: 7.7 feet lis Sample Data i kr Material a WC o 43-- o z= 0 Description J • °i t °'� 0 C V ° E m X Percent Fines a w o 2 r °�� Numbere 0 A SPT N Value p — 0 10 20 30 40 0- Asphalt(6-inch thick) ,1,641 • Base aggregate(12-inch thick) Medium stiff,moist,brown-red,SANDY SILT(ML). Infiltration test conducted at 2.0 feet. See text for additional details. ,••• Co 2 18 73 a GS,WC o 2 5 of- - i z air o I- 0 5 2 18 grades to brown,SILT,trace sand 5 2:2 • w _ • 90 3 GS,WC dig r 4 r 7 0 N CV rn N 'n- - F z Z k9 0 Mg - 31.... .... .._ 0 55 R L6 5 s Gs we ' Very dense,dry,brown,SILTY SAND(SM).(Decomposed Basalt) • re g Refusal at 8.4 feet. 55/1st 5" Q' (Due to bedrock.) 0 um w- 10— —10 W 0 w I- - m D CO- - - 8, to N W ,c) o N - _ lel 0) co z- - - 0 cn 0 '- 15— —15 +UW N m_ N N Y 0- - 0 CO W 0 z p N - LL gib N_ - _ N I- m 20— —20 a0 arr cc ca m ' General Notes: rair z 1.Refer to Figure A-1 for explanation of descriptions and symbols. 2.Material descriptions and stratum lines are interpretive and actual changes may be gradual. Solid stratum lines indicate distinct contact between material strata or geologic a units. Dashed stratum lines indicate gradual or approximate change between material strata or geologic units. LL 3.USCS designations are based on visual-manual identification(ASTM D 2488)unless otherwise supported by laboratory testing(ASTM D 2487). tali O 4.Groundwater level,if indicated,is at time of drilling/excavation(ATD)or for date specified.Level may vary with time. zV Project: Jackson Food Stores#530-SW Bull Mountain Road Boring Log Figure A-3 o Location: Tigard,Oregon om H WSER Project No.: 15927-11 B-2 Sheet 1 of 1 w. _ Date Started: 7/5/17 Date Completed: 7/5/17 Drilling Contractor/Crew: Dan J.Fischer Excavating,Inc./Greg WO Logged by: K.Smyth Checked by: J.Harmon Drilling Method: Solid Stem Auger Location: N:645,543.61 E:7,613,519.83 Rig Model/Type: Big Beaver/Trailer-mounted drill rig Ground Surface Elevation: 306 feet Hammer Type: Cathead Horizontal Datum: OR State Plane N,NAD 83,ft. Hammer Weight(pounds): 140 Hammer Drop Height(inches): 30 4446 Vertical Datum: NAVD 88 Hammer Efficiency(%):Measured: NA Estimated: 60% Comments: Auger Diameter: 3 inches Casing Diameter: NA Total Depth: 20.41 feet Depth to Ground Water: 8 feet 4411 Sample Data -IT c a) c L g Material u, PL WC LL ° -- 8 r = Description I • + i° U o a X Percent Fines a aai o a '$ Number m A SPT N Value in W m Tests - 10 20 30 40 0 0- -.4 Grass/roots(2-inch thick) J- air o - Loose,moist,brown• ,SILTY SAND(SM). M • • :Yil 2 18 - - 42..._ co a 3 aL,s we Infiltration test conducted at 3.0 feet.See text for additional details. I • I X O 5 8 vi- z air O o 5 5 18 Stiff,moist,brown,SILT(ML). 89 5 a wr0 _ 7 s,w Gc • x W r' 8 15 n — cs' O up _- N_ il N. z 5 18 _-D_ c W um 6 - Gs we grades to very stiff,wet L #5 a 10 16 aa- - r a 0 mis o- 10— 10 LL_ 0 ce Lo Z N J ,ate J D O M N W Q:- - 0 qms co co z- - - 0 U - 15— mitc 1t3 Note: No blow counts recorded for this sample. 15 m� 34 rn N-a) - L - N Y s 0 a W F 0 z- - - ii 4W1 N_ _ N r iii 20 50 4� 4 3-5 (ThfVery dense,moist,gray,SILTY GRAVEL(GM).(Decomposed Basalt) y50/1st 4 20 ,ter Refusal at 20.4 feet. 50/1 st 4" (Due to bedrock.) cc m -' General Notes: 411111 i 1.Refer to Figure A-1 for explanation of descriptions and symbols. 2.Material descriptions and stratum lines are interpretive and actual changes may be gradual. Solid stratum lines indicate distinct contact between material strata or geologic 5 units. Dashed stratum lines indicate gradual or approximate change between material strata or geologic units. 3.USCS designations are based on visual-manual identification(ASTM D 2488)unless otherwise supported by laboratory testing(ASTM D 2487). ar 0 4.Groundwater level,if indicated,is at time of drilling/excavation(ATD)or for date specified.Level may vary with time. J zV Project: Jackson Food Stores#530-SW Bull Mountain Road Boring Log Figure A-4 to o Location: Tigard,Oregon o I OwsE Project No.: 15927-11 B-3 Sheet 1 of 1 Date Started: 7/5/17 Date Completed: 7/5/17 Drilling Contractor/Crew. Dan J.Fischer Excavating,Inc./Greg Mil Logged by: K.Smyth Checked by: J.Harmon Drilling Method: Solid Stem Auger Location: N:645,499.21 E:7,613,481.07 Rig Model/Type: Big Beaver/Trailer-mounted drill rig Ground Surface Elevation: 306 feet Hammer Type: Cathead Horizontal Datum: OR State Plane N,NAD 83,ft. Hammer Weight(pounds): 140 Hammer Drop Height(inches): 30 dill Vertical Datum: NAVD 88 Hammer Efficiency(%):Measured: NA Estimated: 60% Comments: Auger Diameter: 3 inches Casing Diameter: NA Total Depth: 10.92 feet Depth to Ground Water: Not Identified M, Sample Data i a� c t $' Material PL WC LL m too z e Description I • 4416 3 m o a Number ° X Percent Fines a o a m A SPT N Value p ul Cl m F Tests 10 20 30 40 C_ Asphalt(6-inch thick) 41111 m • Base aggregate(18-inch thick) -0 - .j, — M I. - - R� _ Loose,moist,gray-brown,SILTY SAND(SM). Ai 3 18 - - • 46._ co 4_1 ik • ' x -, 4 AL,GS,WC`.'•.. 0. O 6 10 ui z 0 5 5 18 grades to medium dense 39 5 a. 12 w o _ 10 GS.WC •• XAA -.O7 ... N le,— — — Z cc w a • a- - a 0 A` • 10 15 g 11 `Dense,dry,gray-brown,POORLY GRADED SAND(SP).(Decomposed 10 o w Basalt) g y ( p • 50 �� 1-N Refusal at 10.9 feet. so/5" (Due to bedrock.) 4iiti —I 0 M al W 0 co z- - - cp Ii 15- -15 am 1 Mil 0 O mr iiiii N_ - _ _N I- m- 20- -20 m } N ct _m J General Notes: iiii = 1.Refer to Figure A-1 for explanation of descriptions and symbols. 2.Material descriptions and stratum lines are interpretive and actual changes may be gradual. Solid stratum lines indicate distinct contact between material strata or geologic 3 units. Dashed stratum lines indicate gradual or approximate change between material strata or geologic units. - 3.USCS designations are based on visual-manual identification(ASTM D 2488)unless otherwise supported by laboratory testing(ASTM D 2487). ow 0 4.Groundwater level,if indicated,is at time of drilling/excavation(ATD)or for date specified.Level may vary with time. o zi� Project: Jackson Food Stores#530-SW Bull Mountain Road Boring Log Figure A 5 m Location: Tigard,Oregon um HARTCROWSER Project No.: 15927-11 B-4 Sheet 1 of 1 dim = Date Started: 7/5/17 Date Completed: 7/5/17 Drilling Contractor/Crew. Dan J.Fischer Excavating,Inc./Greg mua Logged by: K.Smyth Checked by: J.Harmon Drilling Method: Solid Stem Auger Location: N:645,364.59 E:7,613,398.60 Rig Model/Type: Big Beaver/Trailer-mounted drill rig Ground Surface Elevation: 306 feet Hammer Type: Cathead Horizontal Datum: OR State Plane N,NAD 83,ft. Hammer Weight(pounds): 140 Hammer Drop Height(inches): 30 del Vertical Datum: NAVD 88 Hammer Efficiency(%):Measured: NA Estimated: 60% Comments: Auger Diameter: 3 inches Casing Diameter: NA Total Depth: 6.5 feet Depth to Ground Water: Not Identified Ali Sample Data a; w ^_ °� c t o Material PL WC LL c 42. 7 w 0 ,t a Description 'X Percent Fines• ' a r w m °21 �� Numberet (? A SPT N Value m 10 20 30 40 0_ Asphalt(6-inch thick) Art U) • Base aggregate(18-inch thick) -0 - .A - M • - - A_ _ Soft to medium stiff,dry,gray-brown,SILT(ML). !mil 2 18 in LI a 2 WC 0 2 4 z cab 0 0 5 10 c 17 grades to very stiff 5 12 w o _ 10 — AL,GS WC X •t - MI rM 50 Very dense,dry,gray,POORLY GRADED GRAVEL WITH SILT(GP-GM). 60/11" \(Decomposed Basalt) / N- - Refusal at 6.5 feet. - z (Due to bedrock.) c5 a w a a- - - a ❑ +ur w- 10— —10 a o M N ciraJ 2 O co Cl, W 2- - - 0 kiiiil N CO 2- - - 0 co Y U <- 15— —15 Ai yI U N N Y 0_ COAll 0 W 1- 0 Z- -' - W Wil Tr --, 20— —20 cc o} N 2 m m -' General Notes: AA s 1.Refer to Figure A-1 for explanation of descriptions and symbols. 2.Material descriptions and stratum lines are interpretive and actual changes may be gradual. Solid stratum lines indicate distinct contact between material strata or geologic 3 units. Dashed stratum lines indicate gradual or approximate change between material strata or geologic units. 3.USCS designations are based on visual-manual identification(ASTM D 2488)unless otherwise supported by laboratory testing(ASTM D 2487). N oO 4.Groundwater level,if indicated,is at time of drilling/excavation(ATD)or for date specified.Level may vary with time. AitJ zV Project: Jackson Food Stores#530-SW Bull Mountain Road Boring Log Figure A-6 o Location: Tigard,Oregon vRTCRO� Project No.: 15927-11 B-5 Sheet 1 of 1 APPENDIX B Laboratory Testing 1111 15927-11 HARTCROWSER September 12,2017 APPENDIX B Laboratory Testing General Soil samples obtained from the explorations were transported to our laboratory and evaluated to confirm or modify field classifications, as well as to evaluate engineering properties of the soils encountered. Representative samples were then selected for laboratory testing at our laboratory. The tests were performed in general accordance with the test methods of the ASTM or other applicable procedures. The results of the tests are included in this appendix. Laboratory Test Results Moisture Content Moisture contents of samples were obtained in general accordance with ASTM Test Method D 2216. The results of these tests are presented on the exploration logs included in Appendix A and summarized on Figure B-1 in this appendix. Atterberg Limits Atterberg limits(liquid limit, plastic limit and plasticity index) of fine-grained soil samples were obtained in general accordance with ASTM Test Method D 4318 02. The results of these tests are presented on the exploration logs included in Appendix A, summarized on Figure B-1 in this appendix, and detailed on Figure B-2 in this appendix. Grain Size Distribution Analyses Grain size distribution analyses were conducted to determine the quantitative distribution of particle sizes in different soil samples. Fines content analyses were performed to determine the percentage of soils finer than the No. 200 sieve—the boundary between sand size particles and silt size particles. The tests were performed in general accordance with ASTM D 6913, D 422, and D 1140. The results of these tests are summarized on Figure B-1. A grain size distribution analysis including determining the sand content of the soil sample is in Figure B-3 in this appendix. NW 15927-11 l'.R7'cROWSER September 12,2017 Water Dry Maximum %<#200 Liquid Plastic Plasticity Pocket Torvane Exploration Depth Content Density Size Pen (%) (pcf) (mm) Sieve Limit Limit Index (tsf) (tsf) B-1 2.5 18.5 B-1 5.0 25.5 0.075 23 B-2 2.5 29.3 0.075 73 B-2 5.0 31.3 0.075 90 B-2 8.0 14.8 0.075 31 INN B-3 2.5 29.0 0.075 42 35 26 9 B-3 5.0 27.2 0.075 89 B-3 7.5 25.8 0.075 95 B-4 2.5 29.3 0.075 46 37 30 7 B-4 5.0 26.3 2 39 B-4 10.0 45.1 0 B-5 2.5 28.8 B-5 5.0 23.9 0.075 12 42 27 16 J a x w N. ,jyy rn 0- 0 0 J w YW H J co m i;d O tfJ w 0 H 0, O 0 U r rn to in 0 0 m w 00 aW �_ Zr:;" to ell 0 co 61 U S y z C- H 0 w 0 0 LL_ T K dos n A Project: Jackson Food Stores#530-SW Bull Mountain Road Figure All Summary of g B-1 a Location: Tigard,Oregon o HOWSER Project No.: 15927-11 Laboratory Results Sheet 1 of 1 ,.:. 60 i Dashed line indicates the approximate / upper limit boundary for natural soils / / 50— / __ v7._. / �O / Cl / / / 40 / / X / LLF / a / z / } / U 30 // / / a / Off' 20— / Ot o // G`, cl / i o 314 a / x / Wi 10— / — —i •co N �j/ ■ i At 4—— j/�CL ML/ l✓j//// Y ML or OL MH or OH 3 a 10 30 50 70 90 110 LIQUID LIMIT a 0 0 J w LL_ 0 ,atM cc H Location and Description LL PL PI -#200 I MC% USCS • Source: B-3 Sample No.: 3-1 Depth:2.5 to 4.0 feet SILTY SAND 35 26 9 42 29 SM 0 ■Source: B-4 Sample No.:4-1 Depth:2.5 to 4.0 feet a 37 30 7 46 29 SM ltiti x SILTY SAND 0 a A Source: B-5 Sample No.: 5-2 Depth: 5.0 to 6.4 feet POORLY GRADED GRAVEL WITH SILT 42 27 16 12 24 GP GM b N 0 O 0 07 W 0 Z mor L Remarks: 0 ;i- ' ■ N m A J d >- a fc 0 J 0 S z Z_ 0 LL 0 F m J 0 rt 111 w A Project: Jackson Food Stores#530-SW Bull Mountain Road Liquid Limit, Fi Q V ure Location: Tigard,Oregon Plastic Limit, and g B-2 0 HARTICROWSER Project No.: 15927-11 Plasticity Index Sheet 1 of 1 x U.S.SIEVE OPENING IN INCHES 1 U.S.SIEVE NUMBERS I HYDROMETER 100 , , 14L--- 11H1 1 95 f I 80 70 -- - - r-- ,---- --;-- . CC UJ z5s j I� . H so- � I ' z W 45 - - ----1— - - -_.-- WU - 40 --- - -- - - - i __ a 35 1 i . z 30 , F a 20 _- / i --II I - . _ 15 f . N m 10 c� 5 l — _i-_-_ z a 0 I a 100 10 1 0.1 0.01 0.001 a GRAIN SIZE-mm a ,,b,. o GRAVEL SAND w COBBLES SILT OR CLAY E coarse fine coarse medium fine 0 a 2 Location and Description %Cobbles %Gravel %Sand %Silt %Clay MC% USCS m • Source: B-4 Sample No.: 4-2 Depth: 5.0 to 6.5 w SILTY SAND 0.0 0.0 61.2 38.8 26 SM cc 0 N z 0 Y U . Q bu rn ui 0) Y 0 ab. 0 ¢] L. H O z XLL PI DBS D60 Dso Dao Du D10 Cc Cu o • 0.538 0.192 0.128 _- N J Y cc Remarks: o • I F z 3 LL W N z A Project: Jackson Food Stores#530-SW Bull Mountain Road Figure a u Particle-Size 9 B-3 ce Location: Tigard,Oregon _ HiRTCROW5E{ Project No.: 15927-11 Analysis Sheet 1 of 1