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Report (36) 111 mS-v- 01(k-002 '13 Su Geotechnical Report 9500 SW 74th Avenue: Two parcel Portland, Oregon Prepared for: Gerritz Custom Homes Portland, OR 13 December 2017 PRO MOPE .rpt 76' OREGON et 4 C 4HEU' ! EXPIRES:coRS * � ' .4; 4.„, g 0 4.who rt,su 3915 SW Plum St Portland, OR 503-816-3689 PROJECT AND SITE DESCRIPTIONS Introduction Rapid Soil Solutions(RSS)has prepared this geotechnical report,as requested, for the proposed 2-parcel partition of the Washington County tax lot currently assigned the state tax lot identification number of 1 S 125DB03700. This parcel is situated near the northeastern corner of the City of Tigard on the eastern side of SW 74th Ave roughly 110 feet south of its intersection with SW Shady Lane and 330 feet north of its intersection with SW Barbara Lane. The site is currently assigned the street address of 9500 SW 74th Ave and contains one single-family dwelling. Adjacent parcels are also residential lots and are assigned the street addresses of 9510 and 9520 SW 74th Ave to the south,9460 SW 74th Ave to the north, 9495 and 9525 SW Shady Place to the east as well as 9505 SW 74th Ave to the west. The site is located 0.20 miles south of SW Taylors Ferry Road,0.32 miles east of SW 80th Ave,0.71 miles southeast of SW Oleson Road,0.74 miles northwest of a Highway 99W and Interstate 5 interchange (I-5 exit 294) and is 1.10 miles northeast of Highway 217. In 1890 the local are was divided into lots by the Map of South West Portland(Book 1,Page 61)and fell within lot 47.In 1938 the Boulevard Heights subdivision divided the local area, and the subject site fell within the larger lot in Tract 1, assigned lot number 23. The legal description of the site is"BOULEVARD HEIGHTS Lot:23 1"though the site only occupies 0.40 acres of the originally 4.89 acre lot 23. The site can be found within the northwest quarter of the southeast quarter of Section 25,Township 1-South,Range 1-West(W.M.)in Washington County, and can be distinguished by the lot number 3700. The latitude and longitude of the site are 45.451349 and -122.752227 (45°27'04.9"N, 122°45'08.0"W). The site can be found along the eastern edge in the Northeastern quarter of the Beaverton 7.5- minute quadrangle. SITE CONDITIONS Surface Conditions The 0.40-acre subject site is situated in an urban/suburban neighborhood in the City of Tigard,in western Washington County.The site and all ofthe parcels surrounding the subject site are in an urban/suburban residential neighborhood zoned as a medium density single- family residential district.The specific zoning,R-4.5 indicates a minimum lots size of 7,500 square feet. The site is surrounded on all sides my similarly sized parcels, ranging in size from 0.16 acres to 0.74 acres.All of these surrounding lots contain single-family residential dwellings. The adjacent structures were constructed in 1976(x2 to the south), 1983 (to the southwest), 1948(x2 to the west and northwest), 1946(to the north)and 1979(x2 to the east and southeast). SW 74th Ave passing along the western edge of the parcel is paved but contains no curbs or sidewalks. A drainage ditch is located along the eastern side of the roadway between the subject parcel and the paved driving area. The subject site is currently vacant and undeveloped. Evidence of a recent demolition was observed on the subject site. Historically the site contained one single-family dwelling originally constructed in 1942.The building was about 2128 square feet in size and appeared not to contain a basement. The unfinished garage was attached at the southern end of the structure and second story living space was located above the garage.A gravel RV parking pad was located at the southwestern corner of the property and an asphalt driveway extended 2 to the southern end of the dwelling from SW 74th Ave. Historical aerial and street-view imagery indicates that the majority of the parcel contained a short-cropped grassy yard with a few scattered trees and shrubs.A shrubbery hedge was situated at or just beyond the northern edge of the parcel.The demolition of the structure created a large area of exposed dirt.A silt fence was installed east of the now demolished structure and the yard area east of this silt fence was left relatively undisturbed. West of the silt fence the structure and all of the large vegetation was removed from the site. The majority of the asphalt driveway was also removed from the site.The demolition and removal of the dwelling left behind exposed soils and tree branches across the entirety of the western two thirds of the parcel. The slopes across the subject site are relatively low. These slopes descend generally southwards, towards a west-flowing tributary to Ash Creek. The average percent slope, derived form a 5-ft digital elevation model of the Portland, Oregon area, is 5%. This 5-ft DEM indicates that the majority of the site contains slopes of less than 5%(blue and grey) with areas contained slopes of 5-10% (green). The northern and southern edges of the site contain areas that are slightly steeper,with modeled slope areas of 10-15%(yellow), 15-20% (orange) and greater than 20% (red). The distribution of these slightly steeper slope areas appear to indicate that historic grading in the area created a slightly stair-stepped or benched appearance,where the majority of the natural grade change was shifted to the outer edges of individual properties. This established low-relief areas in the center of the subject site and slightly steeper steps on the exterior edges. The step along the northern side of the property line is moderately abrupt,but is only about 1'tall.The step on the southern end of the parcel appears to slope from edge of the historic driveway southwards and accommodate roughly 2' of vertical elevation change. Grading on the parcel adjacent tot eh the eastern half of the southern property line appears to have created a relatively short,but more steeply descending step on the southern side of the fence. MetroMap classifies the entire site as not exceeding 10% slope. No standing or flowing water was observed on the subject site. r4 P 4 4 ,# 3 Regional Geology The subject site is tucked near the eastern edge of the Tualatin Basin on slopes ascending towards the Tualatin Mountains. Current geologic literature P2'34'5'6'7'8'9 classifies the 1 http://www.oregongeology.org/sub/ogdc/index.htm 2 Burns,W.J.,Madin,I.P.,and Mickelson,K.A.,2011,Landslide inventory maps of the Beaverton quadrangle, Washington County, Oregon:Oregon Department of Geology and Mineral Industries, 3 slopes underlying the subject site as at or near the contact between older basin-fill deposits and the younger, thick layer of Missoula Floods deposits that blankets most of Tualatin Basin. The deposits on site are further classified as part of the fine-grained facies(sand and silt)of the Missoula Floods deposits. Geologic History The subject site is generally situated within the forearc basin of the Cascadia subduction system between the Cascade Range (volcanic arc) and the Coastal Range (accretionary/subduction complex). The site is part of the Tualatin Basin, one of several topographic and structural depressions that collectively constitute the Puget-Willamette forearc trough. This topographic and structural basin generally has low topographic relief. The basin formed due to tectonic compressional stress that both intimated the basin's formation and produced prolonged the enlargement of the basin. As the Tualatin Basin continued to subside during the late Miocene and Pliocene,it filled with continental fluvial and lacustrine sediments deposited by ancestral versions of modern rivers.This resulted in a thick accumulation of material preserving a complex record of deposition and erosion (aggradation and incision).Across most of the basin,deposits laid down by ancient rivers are buried beneath the thick deposit of catastrophic flood deposits,though along the edges of the basin these ancient river rocks are occasionally the surficial geologic deposit. The same tectonic forces that formed the basin created the Tualatin Mountains, rising northeast of the subject site.This northwest-southeast oriented ridge separates the Tualatin and Portland Basins. The uplifted ridge is structurally a late Cenozoic anticline bound by reverse faults that dip towards the anticlinal axis.This uplifted band of bedrock is the result of the compressional tectonic forces and produces a prominent structural feature that separates the Portland basin from the Tualatin basin. Similar structures are common in the Interpretive Map Series 34,scale 1:8,000. 3 Ma,L.,Madin,I.P.,Duplantis,S.,and Williams,K.J.,2012,Lidar-based surficial geologic map and database of the greater Portland, Oregon, area, Clackamas, Columbia,Marion,Multnomah, Washington, and Yamhill Counties, Oregon, and Clark County, Washington:Oregon Department of Geology and Mineral Industries,Open-File Report 0-2012-02,scale 1:8,000. 4 Beeson,M.H.,Tolan,T.L.,and Madin,I.P., 1989,Geologic map of the Lake Oswego quadrangle, Clackamas, Multnomah, and Washington counties, Oregon:Oregon Department of Geology and Mineral Industries,Geological Map Series 59,scale 1:24,000. 5 Schlicker,H.G.and Deacon,R.J., 1967,Engineering geology of the Tualatin Valley region:Oregon Department of Geology and Mineral Industries,Bulletin 60,scale 1:48,000. 6 Trimble,D.E., 1963,Geology of Portland, Oregon and adjacent areas:U.S.Geological Survey,Bulletin 1119,scale 1:62,500. 7 Burns,Scott,Growney,Larry,Brodersen,B.,Yeats,R.S.,and Popowski,T.A., 1997,Map showing faults, bedrock geology, and sediment thickness of the western half of the Oregon City 1:100,000 quadrangle, Washington, Multnomah, and Marion Counties:Oregon Department of Geology and Mineral Industries,Interpretive Map Series 4,scale 1:100,000. 8 Madin,I.P.,2004,Geologic mapping and database for the Portland area fault studies:Final report, Clackamas, Multnomah, and Washington Counties, Oregon:Oregon Department of Geology and Mineral Industries,Open-File Report 0-04-02,scale 1:100,000. 9 Gannett,M.W.and Caldwell,R.R., 1998, Geologic framework of the Willamette lowland aquifer system, Oregon and Washington:U.S.Geological Survey,Professional Paper 1424-A,scale 1:250,000. 4 northwestern Willamette Valley, where they formed to accommodate margin-parallel shortening of the Cascadia forearc. The ridge is roughly 350 meters tall. The steep eastern slopes are steep and terminate abruptly along the trace of the nearly linear Portland Hills Fault. This fault forms a sharp contact between volcanic bedrock exposed within the mountains and the sedimentary deposits and artificial fill along the edge of the Willamette River. The western slopes of the Tualatin Mountains descend irregularly towards the structural and topographic Tualatin Valley basin. At the end of the last glacial maximum,an ice damn in western Montana began to melt.The periodic failure of the ice damn retaining Glacial Lake Missoula resulted in dozens of gigantic floods that stretched from their origin in Montana generally following the Columbia River and eventually reaching the Pacific Ocean.The hydraulically restrictive Oregon Coast Range causes the sediment filled waters to temporarily pond across much of the Willamette forearc trough including the Portland, Tualatin and Willamette basins. The floodwaters, which reached an elevation of 400 feet above sea level,soured many areas down to bedrock and buried others beneath thick layers of gravel,sand and silt that can be divided into a fine- grained and course-grained units.Dramatic scour features and giant bars can be seen within the Portland Basin,and demonstrate the great influence the floodwaters had on shaping the Quaternary geomorphology of the region. The sediments are generally comprised of unconsolidated silt, sand,and gravels were emplaced between about 21,000 to 12,000 years ago. *It >41 Artificial Fill Ls L andslide deposits Subject Site Rr -4,4P0-$' Creek Alluvium wFine Grained Missoula Floods Deposits B3 '44,° Boring Volcanics 4040 Ancient River Rocks 0 0.5 1 2 Miles Site Geology The sediments brought into the local lowlands by the Missoula Floods were deposited when the waters slowed down, blanketing older fluvial and igneous deposits with swaths of 5 rhythmic sedimentary beds.Various studies have divided the Missoula Floods deposits into distinct facies defined by grain size. Around the subject site the sedimentary deposits are described as falling within the sand and silt facies. The flood deposits within the Tualatin Valley are predominantly slack water silts that cover the valley floor up to 35 meters thick and can be found on slopes up to an elevation of 100 to 115 meters. The fine-grained deposits of the Missoula Floods are described as an unconsolidated light- brown to light-gray silt, clay and fine to medium sand. The sediments are deposited in a series of distinct layers, a few inches to a few feet thick, each of which represents a single flood. The finer sediments are predominantly quartz and feldspar and also contain white mica. The coarser sediments can be comprised of Columbia River Basalt fragments.Poorly defined beds of 1-to 3-feet thickness are observed in outcrops, and complex layering has been recorded in boreholes. These deposited have been interested as slack-water sediments settling form the slowing floodwaters. In some areas of this unit, it can include sediments compositionally similar to loess.Soil development commonly introduces significant clay and iron oxides into the upper 6-10 feet of the deposit. Most map sources indicate that the contact between the Missoula Flood deposits and the underlying basin-fill deposits occurs near or at the subject site. This contact is difficult to map as much of the region contains thick surficial deposits and the Missoula Floods deposits pinch out against the older unit.The nature of this contact means that the fine-grained silts of the Missoula Floods taper in an easterly direction and may even merge into the fine-grained surficial deposits that are generally found draped over much of the local area. The `Ancient River Rock' of Ma et al (2012), which is referred to as the `undifferentiated sediments'by Beeson et al(1989),is further classified at the subject site by Madin(2004)as part of the Hillsboro Formation. The ancient river rocks of Ma et al (2012) comprises the youngest bedrock in the Portland area,and it typically comprised of cemented and compacted sediments deposited by the ancestral Tualatin,Willamette,Clackamas,Sandy and Columbia Rivers.They include layers of sandstone,mudstone,siltstone,and conglomerate or cemented gravel. In the Tualatin Valley, there are almost 1,000 feet of siltstone, mudstone and sandstone mostly derived from older sedimentary rocks of the Coast Range.These rocks may have been laid down as long ago as 15 million years after the cessation of the Columbia River Basalt lava flows, as a recently as 2.5 million years when the Boring volcanic field became active.The Hillsboro Formation is described as claystones,siltstones and sandstones that were deposited in fluvial (river) and lacustrine (lake) conditions over Columbia River Basalt group deposits.The unit is found west of the crest of the Tualatin Mountains.Madin (2004) indicates that the unit includes portions of QTs (undifferentiated sediments) of Beeson and others (1989, 1991) and portions of the Sandy River Mudstone Equivalent of Madin(1990). 6 Field Exploration and subsurface conditions RSS excavated total of two(2)hand augur were excavated in the area of the new garage.The locations of the borings are shown on figure 3 in the appendix.A GIT,geologist in training observed the drilled and logged the subsurface materials. The soil logs were compiled by a geotechnical engineer.The logs were created using the Unified Soil Classification and Visual Manual Procedure(ASTM-D 2488).The soil conditions were stiff CLAY to a depth of 4feet. Groundwater was not encountered. Moisture contents varied from 29.9%to 34.8%. Foundation Design This depth may be locally variable and should be confirmed by a geotechnical engineer or their representative at the time of construction. Continuous wall and isolated spread footings should be at least 16 and 24 inches wide, respectively. The bottom of exterior footings should be at least 16 inches below the lowest adjacent exterior grade. The bottom of interior footings should be at least 12 inches below the base of the floor slab. Footings placed into the stiff CLAY shall be designed for an allowable bearing capacity of 1,500 pounds per square foot(psf) at 1 ft below grade. The recommended allowable bearing pressure can be doubled for short-term loads such as those resulting from wind or seismic forces. Based on our analysis the total post-construction settlement is calculated to be less than 1 inch, with differential settlement of less than 0.5 inch over a 50-foot span for maximum column,perimeter footing loads of less than 100 kips and 6.0 kips per linear foot. Lateral loads on footings can be resisted by passive earth pressure on the sides of the structures and by friction at the base of the footings.An allowable lateral bearing pressure of 150 pounds per cubic foot(psf/f) below grade may be used.Adjacent floor slabs, pavements or the upper 12-inch depth of adjacent, unpaved areas should not be considered when calculating passive resistance. An angle of internal friction of 28 degrees can be used. See below site photo of poured foundation. Seismic Design Criteria The seismic design criteria for this project found herein is based on the IBC 2012/15 from the USGS Earthquake Hazards Program. A summary of IBC seismic design criterion below using the following Lat 45.451349 and Long of-122.752227: Short Period 1 Second Maximum Credible Earthquake Spectral Acceleration Ss=0.989g S1 =0.426 g Adjusted Spectral Acceleration Sms= 1.092 Sml =0.671 Design Spectral Response Acceleration Perimeters Sds=0.728 Sdl=0.447 7 Geohazard Review The Oregon HazVu: Statewide Geohazard Viewerl0, Metromapl 1 and Portland Maps12 were reviewed on 07 December 2017 to investigated mapped geological hazards.This review indicates the parcel is situated outside the 100-year floodplain as mapped by FEMA. The expected earthquake-shaking hazard is classified as `severe' with a mapped liquefaction hazard classification of `moderate' to `high'. The nearest fault, mapped as active by DOGAMI,is the NW-SE oriented Molalla-Canby Fault,situated about 2.2 miles southwest of the subject site.Northeast of the subject site,the NW-SE oriented Oatfield fault is roughly 3.2 miles away.IMS-1513 rates the site vicinity as having a peak horizontal acceleration of 0.7 to 0.8g for a magnitude 6.8 Portland Hills Fault earthquake. This falls on the Modified Mercalli Intensity scale within the category of`violent shaking'.Violent shaking can result in considerable damage in specially designed structure, will throw well designed frame structures out of plumb and produce great damage in substantial buildings, with partial collapse.The DOGAMI SLIDO 14 interactive map and IMS-34 do not include mapped slides located on or adjacent to the subject site. The nearest slide is a small debris flow along the banks of the west-flowing tributary to Ash Creek,roughly 0.28 miles southeast of the subject site. The Landslide Hazard classification presented by DOGMAI indicates that the subject site has a landslide susceptibility of moderate(landsliding possible).Lidar imagery depicts a relatively smooth hillside with some benching produced by development. No topography indicative of landslide was observed on site or in available lidar imagery. Construction Observations Satisfactory pavement and earthwork performance depends on the quality of construction. Sufficient monitoring of the activities of the contractor is a key part of determining that the work is completed in accordance with the construction drawings and specifications. I recommend that a geotechnical engineer observe general excavation, stripping, fill placement, and sub-grades in addition to base. Subsurface conditions observed during construction should be compared with those encountered during the subsurface explorations. Recognition of changed conditions requires experience. Therefore, qualified personnel should visit the site with sufficient frequency to detect whether subsurface conditions changes significantly from those anticipated. Limitations This report has been prepared for the exclusive use of the addressee,and their architects and engineers for aiding in the design and construction of the proposed development. It is the 10 http://www.oregongeology.org/hazvu/ 11 http://gis.oregonmetro.gov/metromap/ 12 http://www.portlandmaps.com/ 13 Wong,I.,Silva,W.,Bott,J.,Wright,D.,Thomas,P.,Gregor,N.,Li,S.,Mabey,M.,Sojouner,A.,and Wang,Y.,(2000),Earthquake scenario ground shaking map for the Portland, Oregon, metropolitan area: Portland Hills Fault M 6.8 earthquake, Peak horizontal acceleration(g)at the ground surface:DOGAMI, IMS-15. Scale 1:62,500 14 http://www.oregongeology.org/slido/index.html 8 addressee's responsibility to provide this report to the appropriate design professionals, building officials,and contractors to ensure correct implementation of the recommendations. The opinions, comments and conclusions presented in this report were based upon information derived from our literature review, field investigation, and laboratory testing. Conditions between, or beyond,our exploratory borings may vary from those encountered. Unanticipated soil conditions and seasonal soil moisture variations are commonly encountered and cannot be fully determined by merely taking soil samples or soil borings. Such variations may result in changes to our recommendations and may require that additional expenditures be made to attain a properly constructed project. Therefore, some contingency fund is recommended to accommodate such potential extra costs. If there is more than 2years time between the submission of this report and the start of work at the site; if conditions have changed due to natural causes or construction operations at,or adjacent to, the site; or, if the basic project scheme is significantly modified from that assumed, it is recommended this report be reviewed to determine the applicability of the conclusions and recommendations. The work has been conducted in general conformance with the standard of care in the field of geotechnical engineering currently in practice in the Pacific Northwest for projects of this nature and magnitude. No warranty,express or implied,exists on the information presented in this report. By utilizing the design recommendations within this report, the addressee acknowledges and accepts the risks and limitations of development at the site, as outlined within the report. 9 A Z o W a a , ,i, ,.,• ; ••!LW>9, • 1 , 14:: b ".t r . -•-.". - , 3_ • ifil ..,:,,,*zt, ,,,., ---....., ,,,,, .,„)'-;7:-"'-ot.,E 2 1 ::, ;;,I-•*. ;;- '-'..;' ' '''''' „Kni Iit 4*AtIi,4;.7 , . ,._. r'''' STATES °f ' ,..,..q.,..t lit-*,.?..,0P ;A,' ,t.'4946,,H211";4*,7f,.*-'4 . ' UNITED F THE INTERIOR ' r4414.e4;*714_,..9 .,re;:4f`It, -0X 47vn. :11,•1111,44, DEPARTMENT ° SURVEY„ t - ,. ,re.,/w...' t3„„altAt2e4"1_41--...,:17,. 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A - nm nr. , 777.7 Figure 2: Subject site location on the Washington County Assessor's Map izt., , .41ipie J'.•$1,41,1. . ... , ..,.,,:t . ,, ,iipir-,,-:!..T.,,,,,,, „,-,,,s,y.c .„,,,,,,,, , . ,, fc ,..... ,, , .., , t,....4%-,..,„:.: .. .. '41' ' . ,„ ',' , .' . ' .A.'71, ' y + s r � k i s V'SX'�' +sm�a }�_ ,.�.x f 7 Figure 3:Approximate boring locations on a 2013 aerial image of the subject site. , . Lab Results Project Name:9500 SW 74th Ave Sample Date 12/6/17 Moisture Sample number HA#1 HA#2 HA#3 1 Date and time in oven 12/6/17 3:00 PM 12/6/17 3:00 PM 12/6/17 3:00 PM 2 Date and time out of oven 12/7/17 1:00 PM 12/7/17 1:00 PM 12/7/17 1:00 PM 3 Depth(ft) 2 4 2 . _ 4 Tare No. 3' 4 5 5 Tare Mass 234' 230' 234 6 Tare plus sample moist 1033 974 1080 7 Tare plus sample dry 849 782 877 8 Mass of water(g) 184 192 203 -.9 Mass of soil(g) '615 - 552 643 - 10 Water Content(%) 29.92 34.78 31.57 Atterberg Limit Test Sample Number: HA#1 Depth: 2' Liquid Limit Plastic Limit 1 2 3 1 2 . 1_Tare No. D#1.1 D#1.2 D#1.3 R#1.1 R#1.2 _ _2 Tare Mass(g) 39.9 39.01 39.36 39.9 38.96 3 Tare Plus Wet Soil(g) 74.37 69.17 69.2 50.22 51.26, 4 Tare Plus Dry Soil(g) 63.47 59.15 _ 58.81 48.06 48.72 - 5 Mass of Water(g) 10.9 10.02 10.39 2.16 2.54 6 Mass of Soil(g) 23.57 20.14 19.45 8.16 _ 9.76 _ . . _ 7 Water Content(g) 46.25 49.75 53.42 26.47 26.02 • 8 No.Blows 28 23 18 55 , 1 54 : , • • . ;•• • .• ; i 4 y=-16.18In(x)+100.29 - R.=0.99748 , - no 1 a 1 -.-.• 51 --- a i- 'L2) 50 E I.. co• 49 : _,,,, 47 ± ',-- 7., 46f ., .• 45 I 10 Number of Blows(N) 100 60 , zz' CH or OH A4 50 - ,' A : Liquid Limit(%) 48.21 i 40 . Plastic Limit(%) 26.25 0 Plasticity Index CYO 21.96 le. : _ USCS Classification CL 21'20 /CL or OL - (1.-Nfr, MI:4(4-. MH of OH 0 10 20 30 40 50 60 70 80 90 100 Liquid Limit(LL or wL) HA#1 Surface Elevation: Q \O, 0 (P. 4* •c- 40- Boring Date:12/6/17 OetFet (.‘1 `°4c° F<e444,1Boring Location:Por tland,OR 0 Drilling Method:Hand Auger TP Top Soil with grass roots -- }<� ML-CL Damp,gray with brown,fine grained,stiff,silty CLAY a_ - 1- �1 -2 P1=22, LL=48 29.9 t- I - h zr ML-CL Damp,medium brown,fine grained,stiff,silty CLAY _ 71J�J1 s- � CL Damp,mottled grattwith brown,very stiff,CLAY 9- 4 Boring completed at depth of 4ft 3 0 � E ! 8- —5 —6 E u_ 0 7 LOG OF BORING Rapid Soil Solutions 9500 SW 74th Avenue Plate 1 John Gerrtiz 4 HA#2 Surface Elevation: ee c6 Gos Age v>e Boring Date:1216/17 OQ�r eFa o`$ cls �o-# aFQ `o� Boring Location:Portland,OR O Q �` O 0 5 1,9 Drilling Method:Hand Auger TP Top Sal with grass roots – – a,,- J> WI-CL Damp,gray with brown,fine grained,stiff,silty CLAY fi- 1� ML-CL Damp,medium brown,fine grained,stiff,silty CLAY yf °- 2 S-3 CL Damp,medium brown,stiff,CLAY —4 34.8 Boring completed at depth of 4ft a E_ —5 o– I H—6 U_ - -7 LOG OF BORING Rapid Soil Solutions 9500 SW 74th Avenue Plate 1 John Gerrtiz li HA#3 Surface Elevation: tie �y J0 ec$+l� 4oJc �� ,ap° Boring Date:1216117 eQr ®� o`er clp ♦o4 aFQ a♦d Boring Location:Portland,OR p Q p .7 5 Drilling Method:Hand Auger TP Top Soil with grass roots – – $– ML-CL Damp,medium brown,fine grained,stiff,silty CLAY c_ `1 6 5 / s� '4 —2 31.6 Boring completed at depth of 2ft _ E—3 pY - 4_ I ,-5 —6 u —7 LOG OF BORING Rapid Soil Solutions 9500 SW 74th Avenue Plate 1 John Gerrtiz