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Report „ 1 Ais rzo// - 7 o 00 a 6 ,,. /35q69 sv FaSEA■vq-K-/ Z-A/ i GettiDESIGNz _ . i i . i • i I April 16, 2010 J EVED . . . Centex Hcinles b'UtLaiNG Div ISION 1 1241 ,Slater Avenue NE, Suite 100 i Kirkland, WA q8088 , 4 Attention: Mr. Torn Brown OFFICE COPY q ;'. Report of geoteChnical Engineering S ;'. ancr keliante:lletter N Propo Tigard ROf:40041 tig4kli 0:1;g40h ,.f. GeoDesign project: Centex i I • , : . , .k. 1 '0 'f . , a INTRODUCTION . _ . :: :, . . ,• , 1 This.report the results of our geotechniCal'ren4ineering.seryteeS:fdr.the proposed I: I re$ideriti41 l at the southwest corner of the int ersection o f IN-SC:ii011S Ferry 1 Road and 5,E 35 in 1 We understand thessitelericOmpasses b 1 40 or ei includes 88 fhe curcentlyy4c:44;Nt.4re developed with iltilities, curb and .paved roadways for future i*identiw.:*eloktnent . 1 1 , , GeoDesign assumed the role of geotechnical engineer of record fOr'tne,,pr and provided f i construction observation services to Integrity NyelOPMent during earthwork our involvement f began in July 2(:)0. and continued until March 2008 A(j'pototiniE for the p roperty was iI completed. byteoPacific Engineering, Inc onjanuarY 1:-, 2:005. ' 0keliirdilary Geof0airi(cal . Engineering ROlVili..5:(17Q4s* Ferry tdW.N 9iiqt;ti S 5044 Ferr Road, Washington County, _Oregon. jnraCidition,eQ.06i6n previously P1 5 0 I recommepdations, for use design of gravity retaining walls in a-letter e ntitled Ce 1 Engineering Services, The Village at Creek, SW Barrows Road and SW Scholls Ferry Road, i i ' Tigard, Oregon, ciatedjune 6, 2007. . II , . . . i . : The current plan is to construct residential structures on the 88 lots that have b oropared Foundation loads were unknown at the time of this report ; we have assumed that they will be i typical of one to four story, wood frame residential structures . We furtherunderstandthat.some . „ site grading will take place to accommodate design elevationS. Cuts and fills are not expected to exceed 5 feet, respectively. A Site Plan showing existing improvements and our hand-auger exploration's is shown on Figure 1.. . , I . I . i . . . _.. 620..1v00;oiw4Pro 15575 SW Sequoia Pkwy • Suite 100 1 Portland, OR 97224 i Off 503.968.8787 ! Fak 503.968.3068 \ irMartM•4741$40444 I 0044k04000AM/ • • t SCOPE OF SERVICES The purpose of our work was to confirm that our previous work is in conformance with the geotechnical engineering report and to provide supplemental recommendations for use in design and construction of the proposed development. Specifically, we completed the following scope of services: • Reviewed in -house files for existing information on subsurface conditions in the site vicinity, prior earthwork, and the previous geotechnical report for the site. • Visited the site and completed a visual surface reconnaissanceto confirm that no additional earthwork has been conducted 'since completion of the project. . Completed eight hand augers to a maximum depth of 7 feet below ground surface (BGS). • Prepared this report, which also serves as a reliance letter, that presents our finding and provides updates to the conclusions and recommendations provided in the previous geotechnical report. SITE CONDITIONS SURFACE CONDITIONS We completed a visual surface reconnaissance at the site During our visit, we observed that the ground surface is slightly sloped down towards the south from the north. As discussed above, the lots 'have been developed with associated utilities, sidewalks, curbs, retaining walls; and asphalt =paved roadways to allow access to the lots. The lots are covered b'y grass,' with :Small patches of blackberry brush near the proposed playground area at the east portion of the property. Areas of pondedwater wereobserved on Lots` 5, 9, 10, and 3 through 32. While on site, we observed the cracks in the_ asphalt roadway on SW Coriander lane. As noted in our field reports, the asphalt was reheated during placement using propane torches, which may have contributed to the cracking. SUBSURFACE CONDITIONS We completed eight shallow hand -auger borings (HA -1 through HA =8) at selected locations across the site. The approximate boriing.locations are shown on Figure 1. Based on our explorations, the shallow subsurface conditions in the area generally consist of compacted fill that is medium stiff to stiff silt with varying amounts 'of clay, s and, and gravel. The fill generally ranges in thickness from 0.2 foot to 2 feet BGS. The fill was encountered in most of the borings except for HA -5 and HA -6, which were completed near the proposed playground area at the east portion of the property. A thin layer of lobse.gravel'with silt and sand was encountered at the surface in HA -6. Native alluvium consists of medium stiff silt with some clay and trace organics. In HA -2, we encountered loose sand with minor gravel and encountered refusal on concrete at approximately 6 inches BGS. We drilled four more borings within a 10 -foot radius of HA -2 and encountered concrete at 3 to 6 inches BGS. The area of the sand fill over concrete appears to extend over Lots 47 through 49. The approximate area is shown on Figure 1. . GEODESIGNz 2: Centex -16- 01:041610 Based on our explorations, the average depth of stripping in lightly vegetated areas will be approximately 1 to 2 inches. Stripping activities should be completed as recommended in the previous geotechnical report. • CONCLUSIONS AND RECOMMENDATIONS ¶ In general, we anticipate that the•geotechnical recommendations provided in the previous geotechnical report are still 'applicable to the site with the exception ofthe additional 1 to. 2 inches of stripping anticipated at the site and.our revised shallowfoundation recommendations. WET WEATHER/WET SOIL GRADING The silty soils at the site are easily disturbed during the' wet season and When they are moist. If not carefully executed, site preparation, utility trench work, and roadwayexcavation can create extensive soft.areas:and significant subgrade repair costs can result. If construction is planned when the surficial soils are wet or may become wet, the construction methods•and schedule should be carefully considered with respect to protecting the subgrade to reduce the need. to over - excavate disturbed :or softened. soil. The •project budget should, reflect the recommendations :below if. construction is planned during wet or when the surficial soils are wet:, _ If construction. occurs when silty, Wet 'soils are present, site preparation activities may need to be accomplished using track mounted excavating equipment that loads removed, material into trucks supported ongranu roads. _ The - thickness. of tle.:granular materialfo.r haul: roads and staging areas•will depend on the amount and type of construction traffic. Generally, a 12- to 1 .8 inch=thiek mat of;imported granular material is sufficient for. light staging ar`eas and the basic building pad but is. generally not expected -to,be °adequate to support. heavy equipment.. or -truck traffic. Thegranular mat for haul roads and areas with repeated heavy construction traffic typically needs to be increased to` between 18 to 24 inches. The actual thickness of haul roads and staging areas •should :bebased on the contractors ;aapproach to site development and the amount and type of construction traffic. The imported granular material should be placed in one • lift over the prepared, undisturbed •subgrade and'. compacted :usin g.,a smooth =drum, : non- ,vibratory roller. In. addition, a geotextile fabric may be required :as a barrier between the sub_ grade and imported granular material in areas of repeated construction traffic. •l The imported granular material should be pit- or quarry-run 'rock, caished, rock, or crushed gravel and sand and - should meet the requirements set forth in the 2008 Oregon, S tandard Specifications for Construction (OSSC) 00330.14 (Selected Granular Backfill) and OSSC 00330.15. (Selected, Stone Backfill). The placement of the imported granular fill should be done in conformance with the specifications.<provided in OSSC 00331 (Subgrade Stabilization)..;. The.geotextile should meet the specifications provided in OSSC 02320.20 (Geotextile Property Values) for soil separation. The geotextile should be installed in conformance -with the specifications provided,in OSSC 00350 (Geosynthetic Installation) material should be fairly well - graded between coarse and fine material • and have less thah 5 percent by dry weight passing the U.S. Standard No. 200 Sieve. GEODESIGN? 3 Centex - 16.01:041610 FOUNDATION SUPPORT Dimensions and Capacities Continuous footings for stud bearing walls should be at least 15 inches wide. The bottom of exterior footings should be at least 18 inches below the lowest adjacent exterior grade. The bottom of interior footings should be established at least 12 inches below grade. Footings bearing on subgrade prepared as recommended above should be sized based on an allowable bearing pressure of 2 pounds per square foot. This is a net bearing pressure; the weight of the footing and overlying can be ignored in calculating footing sizes. The recommended allowable bearing pressure applies to the total of dead plus long -term live loads and can be increased by one -third for short -term loads (such as those resulting from wind or seismic forces). • Based on our analysis•and ex'pe'rience with similar soils, total post = construction settlement should be'less than 1 inch,'with differential settlement of les's than 'A inch over a50 -foot span. Resistance to Sliding Lateral loads on footings can be resist by passive earth pressure on the sides of the structures and by friction on the`bas.e of the footings. Our analysis indicates Olaf the available passive.earth pressure for footings confined by on- site'soils and structural fills is 350 pounds per cubic -foot, modeled as an :equivalent fluid pressure. Adjacent concrete slabs, pavements, or the upper 1.2- inch' adjacent, unpaved' areas should not be considered•when calculating passive resistance: n` , addition; in order to rely passive resistance, a minimum of 10 feet-of horizontal clearance must exist between'the'face of`tli'e footings and adjacent down - slopes. For footingsin contact the on sitenative material,'a coefficient'of friction equal to 0.30 may be used when calculating resistance to sliding. This value'sh'ould be increased to 0:40 for crushed rock or imported granular.fill: ` • Foundation Drains Foundation drains should be.considered on the outside of the perimeter footings. of all buildings and -routed to a suitable' discharge because of the potential for shallow groundwater. The foundation drains should consist of 4 inch= diameter perforated drainpipe embedded in a minimum 24.00t -wide zone of drain rock. Drain rock should consistolangular, granular. Material with a maximum particle size of 2 inches and should meet OSSC 00430.11 (Granular Drain Backfill Material). The material should be free of roots, - organic- matter; °and other unsuitable materials; have less than 2 percent by dry weight passing the U:S, Standard No 200 Sieve (washed analysis), and have at least at least two mechanically fractured faces. Drain rock should be wrapped in a geotextile'fabric that meets the specifications provided in OSSC 00350 (Geosynthetic Installation) and OSSC 02320 (Geosynthetics)for drainage geotextiles. CONSTRUCTION CONSIDERATIONS All footing and floor subgrades should be evaluated by the project geotecllnical engineer or their representative to confirm suitable bearing conditions. • Observations should also confirm that all GEO DES I G N z 41 Centex -16 -O l :041610 I I i I loose or soft material, organics, unsuitable fill, prior topsoil zones, and softened subgrades (if 1 present) have been removed. Localized deepening of footing excavations may be required to i. penetrate deleterious materials. i I If footing excavations are conducted during wet weather conditions, we recommend that a minimum of 3 inches of granular material be placed and compacted until well -keyed at the base of the excavations. The granular material reduces subgrade disturbance during placement of forms and reinforcement and provides clean conditions for the reinforcing steel. i i 1 r We appreciate the opportunity to be of continued service to you. Please call if you have questions concerning this report or if we can provide additional services. i . Sincerely, s GeoDe Inc. C;0‘; i `Viola C. Lai, P.E., G.E. " ` I - r ia. i Project Engineer '- ! r e ,.,. , „It, ,, slIEG,#)N — , I Brett A Shi iton, P.E., G.E. T I 'Principal Engineer ,`_ . .PIKES ,. : -` y;0 VCL:BASkt Attachthents Two copies submitted Document ID: Centex- 16 -01- 041610- geolr.doc i © 2010 GeoDesign, Inc. All rights reserved. I I I 1 I 1 I i . i i • i i G EODESIGNV 5 Centex -16- 01:041610 i f f FIGURES Printed By. cdavls I Print Date: 9/16/2010 1:50:19 PM He Name: \ \ geodesign.local\ Files 'obi \A -D \Came% \Centex.l6 \Centex.16 -01 \Figures \CAD \Centex- 16- 01- SPO1.dwg I Layout: FIGURE I f — ( -- --I--- 1! i I i i - - - "-- , i i I- - i L�._ [I I It , ii I i . • i { %.° f V I / I _ - I t r ( f t p 1 --/ / / -1--- • . -„ - / ,• / • . p A I I I . il ,i .. 74, K ,,,, / , : , " / /1 • r . A .'8 'T ;) . - I mf F • A : f , - / aq J / I f i - i us �� s' . a z, / i I I I i ,, • :,-.. . ,,P' ./ ,...." . I , /7---.. /, / ,' . - Rio' r • A , � % i , P J f / /i • / f , j: / a ' L • ��� J F'i �fb�. f / M l C t '.j ye a • . / p ia 'I / ' / v • /r o b i % j WAN a 1 F itioitier . I f CI 0� j j E • z v li 0 ; * // 1 y i , � mL' \\ pm 1`' I . � / N,SMS 11 I : -=' f r � n, -- H s 2 m D z 3 � B O 41) r Q Z c, 2 2 w Al, . O O ;,* N z n 02 n c P , A D A O N F O O m O G CENTEX -16 -01 SITE PLAN fsis SW Stgl■I. Parkway • Sidle 100 • 0■091and oR APRIL 2010 PROPOSED TIGARD RESIDENTIAL DEVELOPMENT 00403.9611AM Fax . 900 503,968.9069 TIGARD, OR FIGURE 1 F- Z w 2 ATTACHMENT FIELD EXPLORATIONS GENERAL ,. We explored subsurface conditions by performing eight hand -auger borings (HA -1 ;through HA -8) to depths ranging from 0.5 foot to 7.0 feet BGS on April 9, 2010. We obtained representative samples of the various soils encountered in the exploration. Classifications and sampling intervals are presented on the exploration logs included in this attachment. The approximate locations of our explorations are shown on Figure 1. .The locations of the explorations.were determined in the field by pacing from existing site features. This information should be considered accurate only to the degree implied by the methods used.. SOIL CLASSIFICATION The soil samples were classified ih accordance with the "Exploration Key" (fable A-1).and "Soil Classification System ".(Table A =2), which are included in this attachment. The exploration: logs indicate the depths at which the soils or their characteristics change, although-the change could be gradual. A horizontal line between soil types indicates an ob (Visual or drill action) Change. If the change occurred between sample locations and was not observed or obvious, the depth was interpreted and the change is indicated u a dashed line. Classifications and sampling intervals are presented on the exploration logs included in this attachment. • G''EODESIGN? A -1 Centex -16- 01:041610 SYMBOL SAMPLING DESCRIPTION Location of sample obtained in general accordance with ASTM D 1 586 Standard Penetration Test with recovery Location of sample obtained using thin -wall Shelby tube or Geoprobe® sampler in general 1 accordance with ASTM D 1 587 with recovery Location of sample obtained using Dames & Moore sampler and 300 -pound hammer or pushed with recovery Location of sample obtained using Dames & Moore or 3- inch -O.D. split -spoon sampler and 140 - pound hammer or pushed with recovery Graphic Log of Soil and Rock Types Location of grab sample Observed between soil or rock units (at depth' indicated) Rock coring interval Inferred contact between n Water level during drilling soil or rock unit's 9 9 (at approximate'depths .indicated) Water level taken on date shown • • GEOTECHNICAL TESTING EXPLANATIONS ATT Atterberg Limits P Pushed Sample CBR California Bearing Ratio PP Pocket Penetrometer CON Consolidation P200 Percent Passing U.S. Standard No. 200 Sieve DD Dry Density RES Resilient Modulus DS Direct Shear SIEV Sieve Gradation HYD Hydrometer Gradation TOR Torvane MC Moisture Content UC Unconfined Compressive Strength MD Moisture - Density Relationship VS Vane Shear OC Organic Content kPa Kilopascal ENVIRONMENTAL TESTING EXPLANATIONS CA Sample Submitted for Chemical Analysis ND Not Detected P Pushed Sample NS No Visible Sheen PID Photoionization Detector Headspace SS Slight Sheen Analysis ppm Parts per Million MS Moderate Sheen HS Heavy Sheen 75 DESIG M EXPLORATION KEY TABLE A -1 15575 SW Sequoia Parkway -Soft 100 Portland OR 97224 Off 503 - 968.8787 Fax 503.968.3068 RELATIVE DENSITY - COARSE - GRAINED SOILS Relative Density Standard Penetration Dames & Moore Sampler Dames & Moore Sampler Re (140 -pound hammer) (300 -pound hammer) Very Loose 0 -4 • 0 -11 0 -4 ' Loose 4 -10 11 -26 4 -10 Medium Dense 16 - 30 26 74 10 30 Dense 30 - 50 74 - 120 • , 30 - 47 Very Dense More than 50 More than 120 More than 47 CONSISTENCY - FINE - GRAINED SOILS Consistency Standard Penetration Dames & Moore Sampler Dames & Moore Sampler Unconfined Compressive Resistance (140 - pound hammer) (300 -pound hammer) Strength (tsf) Very Soft Less than 2 Less than 3 Less than 2 • Less than 0.25 Soft 2 -4 3 -6 2 -5 ... 0.25 -0.50 Medium Stiff 4 - 8 ,6'- 12 5- 9 0.50 . Stiff 8 -15 12 -25 9 -19 1.0 -2.0 Very Stiff 15 -30 25 -65 19.. ,31 2.0 -4.0 Hard More than 30 More than 65 More •than'31 ' More than 4:0 • ,PRIMARY SOIL DIVISIONS GROUP SYMBOL GROUP NAME CLEAN GRAVELS GRAVEL (< 5% fines) GW or GP GRAVEL • GRAVEL WITH FINES GW -GM orrr.GP -GM GRAVEL ` with silt • (more than 50% of (> 5% and < 12% fines) GW -GC or GP -GC GRAVE wit "cl coarse fraction y COARSE :GRAINED retained on CM. silty GRAVEL N G .. ,RAVEL GRAVELS WITH FINES SOILS (> 12% fines) GC clayeyGRAVEL GC -GM silty, clayey GRAVEL (more than 50% CLEAN.SANDS . ' • retained on SAND ( <5% fines) SW or SP SAND No: 200 sieve) - - SANDS'WITH FINES SW SMor SP -SM, • , SAND s with, silt (50% or more of > 5% and < 12% fines • coarse fraction • fines) . ,:o - r. •SR. SC - SAND.;uvith clay • passing • - SM .silty SAND. .. SANDS WITH FINES No 4 sieve) SC • - ' `clayey .. (> 12 % fines) SC -5M ' silty; clayey_S ML SILT FINE - GRAINED CL CLAY SOILS Liquid limit less than 50 C silty CLAY . (50% or more SILT AND CLAY OL - ORGANIC SILT or ORGANIC CLAY passing MH SILT Liquid limit 50 or No. 200 sieve) CH , CLAY greater OH ORGANIC SILT or, ORGANIC CLAY HIGHLY ORGANIC SOILS PT PEAT ; MOISTURE ADDITIONAL CONSTITUENTS CLASSIFICATION -,,. ' Secondary granular components or other materials . Term Field Test such - as organics, mari;made debris; etc. Silt and Clay In: Sand and Gravel ln: very low moisture, Percent . Fine - Grained Coarse- Percent Fine - Grained Coarse- dry dry to touch Soils Grained Soils 7 Soils Grained Soils moist damp, without < 5 trace trace < 5 trace 'trace visible moisture . 5 - 12 minor with . 5 - 15 minor minor we visible free water, > 12 some silty /clayey " 15 - 30 with with usually saturated ; - d :, , > 30 sandy /gravelly sandy /gravelly Et C SIGN? 15575 SIN Sequoia Parkway -Suite 100 SOIL CLASSIFICATION SYSTEM TABLE A -2 Portland OR 97274 Off 503.968.8787 Fax 503.968.3068 z 0 w A BLOW COUNT DEPTH = MATERIAL DESCRIPTION ®MOISTURE COMMENTS FEET a W 0 w Q CONTENT cc w H N u HA -1 0 so 10 • 0.0 Medium stiff to stiff, light brown with - orange and gray mottled SILT (ML), some clay, trace gravel, milled wood, red plastic fragments, organics (rootlets), and charcoal; moist (1 -inch- ,thick root zone) - FILL. _1 1.8 2.5 Medium stiff, light brown SILT (ML), , some clay, trace organics (rootlets); moist (alluvium). becomes stiff at 3.5 feet - stiff to very stiff, orange mottles at 4.0 ® Surface elevation was not \feet r 4 measured at the time of 5.0 Exploration completed at a depth of 4.5 exploration. feet. 7.5 — • • 0 so 100 HA -2 o 50 100 0.0 d tour = ere borin s within • Loose, gray brown SAND (SP), trace to Hand au 9 9 a 10 -foot radius of HA -2 and minor gravel; wet _ FILL. 0 • - encountered concrete at 0.25 to - Exploration terminated due -to refusal 0:5 foot.' on "cohcrete at 0.5 foot. Surface elevation was not measured'at the time of - exploration. • 0 2.5 z it a F-. 0 u - z u O 5 .0 w u " co • a - 0 7 7.5 — F- z - w U w - u Q a w w N F- 0 SO 100 DRILLED BY: GeoDesign, Inc. staff LOGGED BY: JPW COMPLETED: 04/09/10 0 BORING METHOD: hand - auger( see report text) .BORING BIT DIAMETER: 3-Inch CENTEX -16 -01 HAND AUGER G EO z 1 5575 SW Sequoia Parkway - Suite 100 = Portland OR 97224 APRIL 2010 PROPOSED TIGARD RESIDENTIAL DEVELOPMENT FIGURE A -1 Off 503.968.8787 Fax 503.968.3068 TIGARD, OR z o 0 = u t „ • BLOW COUNT DEPTH u Q z a ® MOISTURE FEET Qd MATERIAL DESCRIPTION w 0 t ; g CONTENT % COMMENTS 2 J W Q Lu I— U HA -3 0 so 100 0.0 Stiff, brown SILT (ML), some clay, trace - organics (rootlets) and gravel; moist IA -- - - (1- inch -thick root,ztne) - FILL. J_ 1.0 _ Soft to medium stiff, brown SILT (ML), - - - trace clay and organics (roots and 1 8 ' \rootlets); moist (buried topsoil). 1 2.5— Medium stiff, light brown with orange _ mottled SILT (ML), some clay, trace organics (rootlets); moist (alluvium). becomes stiff at 3.5 feet - stiff, light brown mottles at 4.0 feet ® Surface elevation was not Exploration completed at a depth of 4.5 4.5 measured at the time of s.o— feet. exploration. • 7.5 — HA -4 0 50 100 o so loo 0.o - Stiff,,brow (ML), clay, ' • organics (rootlets), gravel,'and asphalt - fragments; moist (1- inch -thick root zone) - FILL. . iv stiff "to medium stiff, light brown at 1.5 El a feet . 2.5— z 'Stiff,`gray SILT (ML), trace fine sand, 3.0 i- - organics (rootlets), and gravel; moist, ° . - low plasticity FILL. . V w grades to gray and light brown at 4.5 o 5 feet — - --‘ with orange mottles at 5.0 feet n. ta Stiff to medium stiff; light brown SILT J s.s 1 (ML), some clay, trace organics El (rootlets); moist (alluvium). Surface elevation was not 'Exploration completed at a depth of 7.0 7.0 measured at the time of � 7 • 5 — feet. exploration. z w u a a w . a - 1- 0 50 100 z S DRILLED BY: GeoDesign, Inc. staff LOGGED BY: JPW COMPLETED: 04/09/10 3 0 J BORING METHOD: hand -auger (see report text) BORING BIT DIAMETER: 3 -inch 3 . c U �vim C �^ ^'� CENTER 16 O1 HAND AUGER a - :E,O ®E . � V V? (continued) G 15575 SW Sequoia Parkway - Suite loo PROPOSED TIGARD RESIDENTIAL DEVELOPMENT x Portland OR97224 APRIL 2010 Off 503.968.8787 Fax 503.968.3068 TIGARD, OR FIGURE A 2 • z o O= u w A BLOW COUNT ~ F- z -' w MOISTURE DEPTH a MATERIAL DESCRIPTION wo H g CONTENT% COMMENTS a J W Q W I- V HA -5 0 50 100 0.0 Medium stiff to stiff, brown SILT (ML), • • - minor clay, trace organics (rootlets); • • _ moist (2- inch -thick root zone). • 2.5 — ® Surface elevation was not • . Exploration completed at a depth of 4.0 4.0 measured at the time of feet. exploration. 5.0 — 7.5 — • 0 50 100 HA -6 . OM 0 50 100 F -6 Loose GRAVELwith and, fine sand , • o2 • \(GP) (2 inches) - FILL. O - Stiff, light brown SILT (ML), some clay, trace organics (rootlets); moist. w o with orange and gray mottles at 2.0 2.5 z feet ® Surface elevation was not Fe a. Exploration completed at a depth of 3.0 3.0 explo mea tion. at the time of feet. 0 U — z U w o o 5.0 — U U , U m a x 7.5 — z z u U U a a .. • r9 N Z o 50 100 0 U DRILLED BY: GeoDesign, Inc. staff LOGGED BY: JPW COMPLETED: 04/09/10 3 0 m BORING METHOD: hand -auger (see report text) BORING BIT DIAMETER: 3 -inch 1 3 u CENTEX -16 -01 HAND AUGER GEO. ®ESIG NZ " (continued) . o Z 15575 SW Sequoia Parkway -Suite 100 PROPOSED TIGARD RESIDENTIAL DEVELOPMENT NT Portland OR 97224 APRIL 2 O l 0 Off 503.968:8787 Fax 503.968.3068 TIGARD, OR FIGURE A -3 z z L7 w A BLOW COUNT DEPTH u Q a Z a 0 MOISTURE FEET a MATERIAL DESCRIPTION > o w < CONTENT% COMMENTS w H u HA -7 • _ _ o so 100 o.o Medium stiff to stiff, brown SILT (ML), • some clay, trace organics (rootlets), gravel, and concrete fragments; moist (1 -inch -thick root zone) - FILL. — - Very stiff, light brown -gray with 2.0 2.5 — orange mottled SILT (ML), some clay, trace gravel; moist - FILL. Stiff, light brown with gray mottled SILT 3•3 (ML), some clay, trace organics (roots); moist (alluvium). ® Surface elevation was not 5.0 sand at 5.0 feet s.o measured at the time of Exploration completed at a depth of 5.0 exploration. feet. 7.s — • • • • • o so 100 HA-43 0.0 . 0 50 100 • Stiff; brown SILT (ML), minor clay, trace organics (rootlets) and gravel; moist (1' -inch -thick root zone)'- FILL. _ Mediutiff to stiff, ligh't - m 's brown with 2.0 2 s - orange and gray mottled SILT (ML), some clay, tra orga (rootlets); moist (alluvium). u - z u w ® Surface elevation was not o 5.0 measured at the time of Exploration completed at a depth of 5.0 5.0 feet. exploration. u co x 7.5 Z w w — — K w a _ h ' . z 0 50 100 u DRILLED BY: GeoDesign, Inc. staff LOGGED BY: JPW COMPLETED: 04/09/10 0 - J BORING METHOD: hand -auger (see report text) BORING BIT DIAMETER: 3 -inch u CENTEX -16 -o1 HAND AUGER • E ® ESIGfVz (continued) • 15575 SWSequoiaParkway - Suite 100 PROPOSED TIGARD RESIDENTIAL DEVELOPMENT = Poitland OR 97224 APRIL 2010 off 503.968.8787 Fax 503.968.3068 TIGARD, OR FIGURE A -4