The URL can be used to link to this page

Home My WebLink AboutPettygrove's 1st Block 34 - Geologic Hazard Assessment - 2021.07.09I. .' t'::' S.s h.atq fuq.4i*sl S'r**u.raq f*ut B'ti; *' u REPORT ENGINEERING GEOLOGY AND GEOTECHNICAL ENGINEERING IVIASSEY COMII{ERCIAL SITE 1220 Water Street Port Townsettd Wnshingtori For: ISLAND CONSTRUCTION P.O. Box 399 Oak Harbor, WA 98277 By: W.D. PURNELL & ASSOCTATES,INC. Consu ltirtg Engin eers & Geologists 2138 Humboldt Street May 8,1997 TABLE OF CONTENTS r:" -a -- - -- :-.INTRODUCTION ..: -. PURPOSE AND SCOPE , qLrE GEOLOGY .. ", Seismic Zone . Field Exploration r -.-:i.-1.-- Surface Conditions Subsurface Conditions , -- Hydrocarbon Observations jl:,.,Ground Water Conditions CONCLUSIONS AND RECOMMENDATIONS ., General I 1 2 2 2 3 3 4 4 4 4'-:'* Site Preparation Fill and Compaction Foundation Support Settlement Potential .. Liquefaction Potential 5 5 6 6 7 7 7 7 I 9 Floor Slab Sup , Retaining Wall Support , I Hydrocarbon Vapor Ventilation , Lateral Earth Pressures ' Drainage Considerations ' ' Pavement Sections 9 ..- :..,Construction Monitori i INDEMNIFICATIONS AND LIMTTATIONS APPENDICES SITEPLAN USCS SOIL CHART TESTPITLOGS 9 10 _ :i::.:-. W.m.F&$'ffifw&w'& May 8, 1997 IUID ASSOCLBTES, INC, Island Corstruction P.O. Box 399 '- Oak Fhrbor, WA 98277 . Amr Mr. t^arry Moses Report Engineering Geology and Geotechnical Engineering Report Massey Commercial Site Port Townsend, Washington Re: INTRODUCTION , , This report presents the results of an engineering geology and geotechnical engineering study for the developmart of the former Chewon Bulk Plant prope(y located at 1220 Water Street, across the street from the Washington , . State Ferry Dock in Port Tonruend, Washington.. Tlre propefi is approximately_28,000 square fbet in arcat . ' erdsnt and is situated within the SWI/4 of the SWI/4 of Section l, Tup. 30N, Rng. lW of the Willamette Meridian. We understand that the development u'ill consist of an approximately 6,600 square feet (ll0'x60'), brick- covered, wood frame building rvith the remainder of the level land utilized for parking. We understand the rear wall of the structure u'ill also be designed as a soil retairring struchtre and that the existing concrete platform on the site will be replaced by a retaining wall rvhich rvill extcnd past the cnds of the present platform. We understand that the building will be supported by shallou'contirtuous and isolated footings and that the maximum load will be approximately 40,000 lbs. ,i-.t , The purpose of this report is to present geotechnical information conceming subsurface soil and ground "' water conditions, and provide geotechnical recommendations for the design and construction proposed for the site. Specifically, our services included the follorving: (l) Observe the soil conditions in four backhoe test pits at the property excavated to approximately 3.5 : to 9 feet below existing ground surface. Three of the test pits rvere located in the vicinity of the proposed building, and the fourth test pit was excavated at the north end of the existing concrete platform at the northwest corner of the proposed parking area (see attached site plan). GEOTOGISTS " ENGINEERS . SCIEIVTISTS P.O. Box 5346, 2138 Humboldt, Beliingham,WA 9822? Phone: (360) 676-9589 800-859-5597 Fax: (360) 676-4625 IUay 8, 1997 Island Construction Report - Enginecring Geologr and Geoteclrnicnl Enginccring (a leyglop logs of test pits as to thickness and depth of each soil unit encountered, based on the Perform engineering analyses, as necessary, in support of our conclusions and recommendations. Prepare this engineering report including a sunlnlary of s'ork performed and our conctusions and reconlmendations for the development of tlre property, including the follorving specific items: Site rvork preparation recommendations, including assessment of the suitability of on-site soils for structural fill and grading and earthrvork procedures.' Various foundation design criteria.' subgrade preparation recomnrendations beneatlr pavement areas.' Hydrocarbon ventilation. SITE GEOLOGY -) Norlhwest Washington has been .occupied by contincntal glaciers at least six times since the Pleistocene Epoch(2.5 million to 10,000 years ago). During these glacial periods (stades) and accompanymg intergtacial p"tioA. (rnter-stades) tlre underly'ing bedrock r','as deeply eroded and a thick sequence of glacial and nonllacial related sediments were deposited over the underll,ing bedrock. The following descriptions of the surficial deposits in tlre vicinity of the subject property uere interpreted from the o{hers. 1986) and our orvn field obs"*"tionr. A.*dilg lo Pessl & others ffgS6l tt.,uU;ot prop"rty i, rmderlain by modified land consisting of a mirture of earlh nraterials ard/or other debris. The steep btutr on ttre northwest side of the subject property consists of glacial till deposited directll,by the Vashon-age ice sheet. Thetill consists of a poorly sorted mixture of rock fragrnents in u{rich the coarser material is firmly embedded in ahighly compact matrix of finer grained nraterial. ^ ' Ourtest pit investigation and site observations rrere consistent rrith the mapping of Pessl & others (1986). Our- t€st pit investigation indicated that the subject property is primarirl, underrain by-nll soils ove, poorly sorted sand' , tlnt we interpret to be beach or tide flat deposits. Seismic Zone The subject site is located in seismic mne 3 per uniform Building code (uBC). Field Exploration Subsurface conditions at tlre subject site uere investigated by excavating d totat of 4 test pits using a rubber-tired backhoe. The test pits rvere excavated on April 25, Igg:t anarvere loosily back-filled on the ruri d"y. The testpits ranged in depth from 3.5 to 9 feet belorv the sunounding ground ru.f"o. The backhoe invigation was w.D. PURNELL& AssocrATEs,INc. Z FtLE:95046E.9ilsLcocEo.Rpr ttt"ry 8,1997 Island Consruaion . Report - Enginecring Gcologr and Geotcchnical Enginccring ' " directd by a geotechnical engineer frorn our staff rtlro maintairrcd corrtirruous logs of soil ud ground nater ,-"- conditions encountered. Soil sa:nples sere cotlected for anall'sis and verification of field logs under controlled* - -'. laboratory conditiors. The. sanples rvere classified visually and nrmually' using the Unified Soil Classification- "' ' Systern in general accordance n'ith ASTIT{ D2488-69 procedure. A copy of t}re Unified Soil Classification System is included in tlre Appendix to this rcport. Ficld dcnsity tcsts rvere cotrducted u'ith a TroxlerrM nuclear densometer to help estimate in-place densities of bluffand existing parking lot nraterials. The edited test pit logs and a plot-plan shorving the test pit locatiorrs is prescnted in the Appendix to this report. Surface Conditions The east side of the property consists of a flat area rarrging fronr approximately 60 to 80 feet in rvidth ---.. 'rutti"tt extends the entire i"ngttt of the propert), fronr north to soutlr. ilre average elevation of the flat area . is approximately I I feet. The rvest side of the propcrty corrsists of a slope of material eroded from the highly consolidated bluff material to the rrnst of the propertv. The slope consists of poorly graded SANDt: - *i!h gravel and is lying at an average angle of 37o. At the tinre of our investigation (4/25/97) there rvere no ,tr"'- buildings on the site. A concrete foundation/retaining rvalt s'hich formerly supported oil storage tanks is situated near the northq'est comer of the level area. .,. Subsurface Conditions Subsurhce conditions at the site were evaluated by excavating four test pits on April 25, 1997 rvith a rubber-tired backhoe using a 2-foot-u.'ide bucket. The test pits rtere excavated to depths ranging from 3.5 to 9 feet below the surrounding surface. Tlre locations and approxinrate surface elevations of the test pits, based on our field measurements, are shorrn on the attached site plan. The test pits rvere loosely backfilled upon completion of the exploration. The soils encountered in the test pits (TP) rvere classified using the Unified Soils Classification System (USCS). The test pit logs are included in the Appendix along s'ith a USCS Chart explaining soil descriptions. Moisture content was determined for several sanrples obtained during the exploration and are indicated on the logs. A ll}"xl2" length of steet reinforcing rod rvas driven into subsurface soils at several '-: depths in the test pits and are indicated on the togs. The iron rod penetration resistance provides an indication of the relative density of coarse-grained soils (e.g., loose, nredium dense, dense, or very dense).: . Where used, penetration data are included on the logs in accordance u'ith tlre USCS Chart. Fill soils rvere encountered in TP-l to a depth of 8.5 feet, in TP-2 to a depth of 5.5 feet, and in TP-3 to a depth of approximately 5.5 feet. The fill soils consisted of poorly graded SAND rvith gravel and were typically encountered with some man-madc dcbris such as clal, pipe or concrete. !/ood u'as encountered at the base of the fill material in Test Pits 2 and 3, and *'ire rope u'as found near the base of the fill in Test Pit 3. Test Pit I was excavated within an area from rvhich hl,drocarbon contaminated soils sere previously removed. Discarded pieces of plastic sheeting were encountered betrveen approximately 3.5 and 4.5 feet in our excavation. 3WD. PURNELL & ASSOCIATES, INC.FILE:95046 E.9NSL,COGEo.RPT lvlay 8, 1997 Island Construaion Report - Enginccring Geologr and Gcotcctrnical Errgirrccring -.. Soil beneath the fill consisted of GRAVEL rvitlr sand irr TP-l and 2 and SAND rvith Gravel in Tp-3 andTP4. The GRAVEL encountered in TP-l and 2 ma1, bc the top lay,cr of the old beach which is underlain -' by more sand deposits. . *- Hydro.arbon Observations - Hydrocarbons lvere encountered in TP-1, 3, and 4. A strong snrell of diesel oil rvas detected in Tp-l and asimilar but less intense odor uas noted in TP-3. Wood encountcred at a depth of approximately 6 feet inTP-3 had a distinct but unidentifiable hydrocarbon odor. Pieces of a tar or an asphalt like substance with . no conglomerate rvere observed in TP-4 at various depths. Ground Water Conditions Ground watertvas not encountered in any of the test pits. The test pits, horvever, were excavated behveenl;00 p.m. and 4:00 p.m., during rvhich tinre the tide n,as rising and betrveen -l and +2.6 feet MLLW (Mean Lorver Low Water). We expect some lag tinre betu,een the actual tide tevel and observed groundwatei level at the site. No soils encountered rvere in a s'et condition, indicating that the soits are very-rvell drained. CONCLUSIONS AND RECOMT\4 ENDATIONS General We conclude, based on our Engineering Geology and Gcotechnical Engineering Investigation, that the looseto dense SANDS encountered observed beneath the site in TP-I, 2, and 3 are of u"rying relative density and may settle differentially under various loads, nraking thern unsuitabte for the foundation 6pe, loads, and settlement sensitive nature of the building planned for the site. Organic matter encountered al the baseof the fill material will degrade rvith time rvhich rnay cause subsurface voids and additional settlement inthe support soils. The conventional, shallorv column (spread) and continuous footings indicated in thefoundation plan are more susceptable to differential settlement than other possible foundations. We recommend, therefore, that the soils or the building foundation be modified to match the type of buitdingplanned for the site. Possible methods to remediate the settlerrrent potential include: l. Remove and recompact soil from beneath the buildirrg footprint,2. Place the building on auger cast piles, 3. . Place the building on a structural stab such that differentiat settlenrent rvill be spread throughout thebuilding, and4- Use grade beams to tie the isotated footings together to limit differentiat setttement. 4WD. PURNELL & ASSOCIATES, INC.FILE:9 5046E.9ilSI,COCEO.RpT I I w 8, t997 Island Constnrction Report - Enginecring Geologr antl Gcotcchnical Engincedng ' "j Geotechnicat engineering services related to the modified design are outside the scope of this report ' ' Site Preparation All fill, organic, or other soft materials slrould be stripped att'av frortt areas to be occupied by buildings, . unless another foundation method is selected. Paverncnt scctiorts and sidervalks may be placed on existing - . soils at the site follorving removal of the organic Ia1'cr (rrficrc it cxists) at the ground surface. Based on our test pit explorations, n'e estimate that the stripping depth slrould be less than I foot in areas which will not- 'ieceive foundations or structural fill. r The soits at the site should exhibit no significant shrinkage or suelling s'ith seasonal changes of moisture -., content. The site, horvever, is strongly influcnced by tidal \\'ater, rvith tide levels of 9 feet (2.5 feet below ... ground surface) not uncommon. We recomnrend that grading artd very shallorv earthwork operations may . .. be performed at any time of year or during any tidal conditions, but that deep earthrvork operation be performed during periods of lorver tide levels. .:,,'Following stripping and foundation excavations, but prior to placctttcttt of any structurat filt or the start of foundation construction, the exposed subgrade under all arcas to be occupied by the buildings, slab-on- , 'grade, pavement sections, sideu'alks, or other stmctural improventents should be inspected rvith a soil probe by qualified geotechnical personnel fronr our office. At that tinte, proof-rolling of the subgrade soils -" may also be recommended. The purpose of proof-rolling is to dctect possible localized zones of soft or toose soil within the subgrade. Proof-rolling is conrnronly perfonned u'ith a loaded dump truck or other suitable construction equipment. Fill and Compaction Structural filt used to obtain final grade elevations for footirrgs, earth supported floor slabs, and other structural improvements, such as pavenrents arrd sidervalks, ntust be properly placed and compacted. All fill should be placed and compacted on a horizontal subgrade surface. The coarse-grained, non-organic soits on-site are suitable for structural fill. We reconrrncnd that inrported structural fill consist of a clean, well graded sandy gravel material (pit mn) containing less than l0% fines (that portion passing the U.S. Standard No. 200 sieve based on a rvet sieve analysis of that portion passing the U.S. Standard No. 4 sieve, GW by USCS ctassification) in accordance u'ith SDOT 9-03.9(l). Placement of fill during wet weather conditions may require pit run material rvith less than 5%o fines be used, such that adequate compaction can be achieved Fill should be placed in maximum 8- to l0-inch loose lifts and be thoroughly compacted. Under building areas, if structural fill is used, it should be compactedto 95yo of maximum dry density as determined by the ASTM D-1557 test procedure. Under pavenrent or sidervalk areas, the structural fill should be compacted to92%o, except for the upper I2 inches of subgrade u'hich should be compacted to a minimum of 95Yo of maximum dry density. We recommend tlrat conrpaction be tested after placement of each lift in the fill pad. At a minimum, the top of the conrpacted structural fill should extend outside all foundations and other structural improvements a distance equal to the thickness of the fill. 5W.D. PURNELL & ASSOCIATES,INC.FILE:95046E.9nlSLCOGEO.RPT ttt"y 8, 1997 Island Construaion . - Rcport - Engincering Geologr nnd Gcotechnicat Enginccring '' -'''' For backfill placed u'ithin zones immediately behind rctaining rvalts or adjacent to foundation stem rvals- '-- only approximately 90Yo relative contpaction shoutd be obtained. Care must be exercised to avoid over- compaction of the rvall backfill to avoid dantagc to the s,all and to rninimize the possibility of developing excess lateral earth pressures against the s'alls. It is important that plumbing and utility trenches be properly backfilled and compacted to minimize thepossibility of localized loss of floor slab or pavement support. Backfill in trenches should meet the appropriate compaction criteria described above and,/or rlashed l/4-inch pea gravel may be used as a substitute backfill material to eliminate the need for compaction. t't"t' ' Foundat'on Support The recommendations discussed in this section assunre tlrat on-site soits rvill be removed and recompacted We recommend that the proposed Massey Commercial Building be supported on isotated cotumn (spread)' and continuous footings founded on the SAND encountered at tt:e site o'ilf if th. existing soils are removed and recompacted beneath tlre building footprint and a distance of approxinrately 6 feet outside the footprint(assuming removal of 6 feet of fill soils). Bearing soit should be firm and-non-l'ietding and free of standing water prior to pouring concrete. Bearing soil that is disturbed during foundation excavation should be' removed or recompacted. We recommend that a geologist or engineer from our office inspect all excavations and the compaction of structural filt prior to construction of footing forms. All continuous and isolated cotumn footings should have minimum u,idths of 18 and 24 inches,' respectivety, and should be founded a minimum of 18 inches betorv the lowest adjacent final grade toprovide adequate frost protection. Shallorv footings srrpported on properly pr.purld subgrade-may be proportioned using a net allou'able bearing pressure of 2,000 psf. The term nei allorvabte bearing pressure - - ' . refers to tlre pressure which can be imposed on the soil at foundation tevel due to the total of dl dlad plus' '' live loads exclusive of the u'eight of the footing or an-\, backfill placed above the footing. These vatues may. . . be increased by one-third for transient u,ind or seisnric loads. !.:;ij;.-i !:-..: . - Settlement Potential Settlementof foundations depends on foundation size, depth, and bearing pressure, as rvell as the strength and compressibility characteristics of the underll,ing soil. For the footing loads and method of construction assumed for the Massey Commerciat Building. We estinrate the total setttement of foundations, assuming recompaction of the fill soils should be smali (lcss than one inclr), assuming a contact pressure of 2,000 psf. 6W.D. PURNELL & ASSOCIATES, INC.FILE:95 046E.9ilSI.COCEO.RPT I I Nlay 8, 1997 Island Construction Report - Enginccring Gcologi' and Gcotcchnicnl Engirrccrirrg . ,-,- .''l,lqusfaction Potential "" ' I-iquefaction can occur during earthquakes from grourrd shakirrg of rclatively loose, saturated cohesionless' - soils. The principal effects of liqucfactiorr includc tcrnporary loss of bearing capacity resulting in differential settlements, lateral spreading, or slidirrg at sites on sloping ground. Liquefaction can occur to depths of 30 feet or more. Ourtest pit exploration of the site revealed sand fill rvith gravel lrom the surface to the maximum depth of- the test pits at 9 feet beneath the surrounding surface. A nrore dense sand and sandy gravel was encountered at the base of the test pits. Sieve anall,sis perfonned of selected samples from the site indicate that the sand material is too coarse-grained to be liquefiable. Accordingly, rve conclude that liquefaction . , potential is not a significant concern for buildings located on the site, based on the soils observed to the _-'. limited depth of our test pits. Floor Slab Support Preparation of the building areas in a manner describcd in the previous sections of this report should provide an adequate base for floor slab support. We reconrnrend that all earth-supported floor slabs be underlain by a capillary la1,er consisting of 4 inclrcs of scrccncd arrd rlashed 5/8" to I " drain rock. A vapor barrier should also be placed belorv the floor slab. The vapor barricr should be covered with a thin layer of clean sand to protect it during concrete placenrent and to aid in concrete curing. After the sand layer is placed, it should be maintained in a relatively dry condition. In addition, the Portland Cement Association recornnrends, "... to prevent problems rvith floor covering materials caused by concrete itself, the follorving steps slrould be taken: (l) use lorv tvater-cement ratio concrete, (2) moisture-cure the slab for five to scven da1,s, (3) allorv the slab a trvo-month or more drying period, and (4) test the slab moisture condition bclorc installirrg the floor covering" (Design and Control of Concrete Mixture", l3th ed.). Retaining WallSupport Foltowing removal of the existing concrete foundation and platform rvhich occupies the location u'here the independent retaining wallwillbe located, subsoils should be removed and recompacted to a depth of 2 feet using methods described in the Fill nnd Compaction section. The retaining rvall may then be placed on supporting soils using a maximum bearing capacitl'of 2, 000 psf. Hydrocarbon Vapor Ventilation Entry of hydrocarbon vapors, as encountered in our test pit investigation, into the building may be limited by the placement of a passive exhaust system connected to roof vents. To install the system, the drain rock installed beneath the slab should be increased in thickness to a minimunr of l2 inches. Lengths of 4-inch 7W.D. PURNELL & ASSOCIATES, INC.Fl LE:95046 8.97\ISL,COCEO. RPT [4ay 8, 1997 kland Construction Report - Enginecring Geolop' and Gcotechnical Enginccr.ing :" rigid perforated should be placed in the middle of tlre drain rock on 20 foot centers and connected at the - side ualls to a manifold systenr rvhich connects all perforatcd pipe The rnanifold should then be connected' ' through the building support system using nortpcrforated pipe to a roof vept. The drain rock and manifold .',, system should then be covered rvith poll'cthvlcrre shccting (10 nril nrininrunr). The floor nray then be completed as discussed in the above sectiorr. Lateral Earth Pressures Lateral earth pressures rvhich develop against subsurface rvalls and retaining rvalls rvill depend on the method of backfill placement, degree of conrpaction, backfitl slope, t1,pe of backfill material, drainage provisions, and the degree to rvhich the rvall can vicld laterally during or after placenrent of backfill. When a subsurface rvall is restrained (rigid rvall) against lateral nrovcnrcnt or tilting, the soil pressure exerted is the at-rest soil pressure. Wall restraint ma1, develop if a rigid structurat netu,ork is constructed prior to bacldlling or if the rvall is inherently stiffor is restraincd frorn rotation. Hoq,ever, if the u,all is allorved to rotate or leld (yielding rvall) so the top of the rtall moves an anrount equal to 0.002 times its height (for cohesionless soil backfrll), the soil pressure exertcd s'ill be tlre active soil pressure. We recommend that yielding rvalls rvith tevel, free-draining backfill and no surcharge loads be designed using an equivalent fluid pressure u'ith a density of 35 pounds per cubic foot (pcf) for ttte active pr.Jur. . condition. For rigid s'alls, \\'e recornn'rerrd a value of 55 pcf (cquivatent fluid pressure) for the at-rest pressurecondition. Design of subsurface u'alls should include appropriate laterat pressures caused by any adjacentsurcharge loads. For surcharge pressures, a unifonnll'distributed lateral pressure of 0.3 times and 0.45 times the calculated additional surcharge rveight should be added for f ielding and non-l,islding rvalls, respectively fie tateral earth pressures recomtnended above for retainirrg u'alls assurne drained conditions behind the walls and therefore do not include hydrostatic \\,ater pressure. Accordinglv, the backfill placed behind retaining walls should be free-draining sand and gravel rvith less ttran three percent passing the No. 200 mesh sieve, based on a wet sieve analysis of that portion passing the US No. 4 sieve. In addition, we reconrmend that a drain be installed belorv the base of tlre u,all rvitlr a minimum 4-inch diameter perforated pipe surrounded by granular filter material such as buckslrot or pea sand. Lateral loads may be resisted b1' passive earth pressures and soit friction. For design purposes, a passive resistance of structural fill placed against the sides of tlre footings nray be considired equiuaieni to the pressure developed by a fluid (equivalent fluid pressure) rrith a density of 300 pcf. This value assumes drained conditions that q'ill prevent the buildup of h5'drostatic pressure in the structural fill. A coefficient of base friction of 0.35 may be used betrveen the base of the footings and the native soils or structurat filt. Drainage Considerati ons 8W.D. PURNELL & ASSOCIATES, INC.FILE:95046E.9ilSl,COcEO.RPT May 8, 1997 Island Construction Report - Enginccring Gcologr and Geoteclrrricnl Engincedng ': -Water that is allorved to collect in lorv-lfing areas rvill percolate into the ground due to the high :.= permeability of tlre subsoils at the site. The buildings should be corrstnrcted such that the surface around.-.'' the buildings will direct stormrvater nrnoffarvay fronr the buildings to a suitable drainage outlet. We "*-- recommend a minimum slope gradient of l% outside of building pads, as u'ell as in pavement and .- . landscaped/lau'n areas. Permanent cut and fill slopcs, hos,ever, slrould not be stecper than 2 horizontal to I _ . vertical (50% gradient). '=''*-. Pavement Sections .. Some of the important factors that affect tlre durability of pavernent surfacing include stability and permeability of the subgrade soils and base nraterials, tlre prcscrrce of ground \\'ater, the trafTic volume, and :'...th!.F"quency of heavy truck traffic. We recommend that typical pavement sections for car and light truck parking areas for this site consist of a minimum of 2 inches of asphatt concrete over at least 2 inches of crushed rock base over existing soils encountered on the site or a minimum of l2 inches of structural fill (i.e., clean, rvell graded sandy gravel pit run material as recommended in the Fill nnd Conrpaction section). All driven'ay or parking areas should be ptaced on a properly prepared subgrade. Access roads or traffic lanes typically should consist of 3 inches of asphalt concrete over 4 inches of crushed rock base over a properly prepared subgrade. Tlrese sections assume a minimum CBR value of about 10. The CBR value is a fi.rnction of soil t1'pe and its densitS'/consistency. Note that proof-rolling of tlre exposed subgrade, inrmediately prior to placing the structural fill layer, will be necessary to ensure the native subgrade soits are firnr and non-1,ielding. The proof-rolling should be observed by a geologist or engineer fronr our staff. An1' soft soils or f ielding areas encountered during proof-rolling should be overexcavated and replaccd at the directiorr of the engineer. Base course materials should be compacted to a nrinimum 95 percent of ma-rimum dry density, as determined by the ASTM D-1557 test procedure. Asphalt concrete should be Class B aggregate material' . conforming to Section 5-04 of the Washington State Dcpartnrent of Transportation (WSDOT) , . . specifications. Crushed rock gradation should be 5/8-inch nrinus, per WSDOT specifications. Construction Monitoring We recommend that W.D. Purnell and Associates be retained to review the foundation design and grading, plans prior to construction to ensure confornrance rvith our recornrnendations. We recommend that a geotechni cal engineer or engineering geologist from our staff be present to inspec_tllr-e__glpilgdgbg1ar{e before acement of structural fill e should also be present during all fill placement, compaction vities,and during any operations to veri$, tlrat the required soil conditions are obtained beneath the proposed building and paved areas. In addition, rve reconrmend that density testing and/or hand W.D. PURNELL & ASSOCIATES, INC.9 FILE:950468.9ilS L,COGEO.RPT May 8, 1997 Islanci Construction Repod - Engineering Geologr antl Gqrtcchnical Enginccring - ' probing be performed on prepared foundatiorr subgrade. Graclation of fill and drainage material shoutd '."- also be checked for conformance rvith our recomrnendations. INDEMNIFICATIONS AND LIMITATI ONS This report has been prepared to aid in the general devetopnrent ofthe site from a geotechnical engineeringstandpoint. The discussion of site development is conceptual in nature and must be refined to take into account the final structural configurations and building la1'out rvith a revierv of final grading ptans. It is'therefore recommended that ue revierv the foundation design for this project during the aesign period inorder to ensure that the plans and design are conrpatible u'ith the reconrmendations in this report and accepted engineering practice. Our test logs shorv subsurface conditions at thc dates and locatiorrs indicated. It is not rvarranted to assumethat they are representative of subsurface conditions at other locations and times. The analyses, conclusions, and recommendations contained in this report are based on site conditions to the limited jepth of our test pits at the time of our exploration. We assume that the exploratory test pits are representati'e ofthe subsurface conditions througbout the site. If, during,ssll5tnrctiori, different subsurface c-onditions from those encountered during our explorations are obsened or appear to be present in excavations, we must be advised promptly so that tve can revierv these conditions and reconsider and./or rnodify our conclusions andrecomrnendations rvhere necessary. Our services are provided in accordance n'ith ttte tenns presented in our General Conditions. As is now common in the industry, our general liability ittsurance carriers specifically exclude coverage for claims or damages related to the release of pollutants. As a condition of our services, it is understood that, to thefullest extent permitted by larv, our clients agree to defend, indemni8, and hotd harmless w.D. purnell & Associates, Inc., its o}1ners, emplol,ees, subcontractors, and agents from any future pollution-retated claimsor damages at the site, including potcntial clainrs from third parties that may name W.D. purnell &Associates, Inc. as a claimant. The earthrvork contractor is responsible to perform all ryork in conformancewith all applicable WISFWOSHA regulations. . W.D. PURNELL A ASSOCTATES, INC.l0 Fl LE:95046 E.97\lS LCOGEO.RpT lvlay 8, 1997 Island Con$ruaion Report - Enginccring Geolog' an d Geotechn ical En ginec ri n g .--:..,We appreciate the opportunity to be of service to 1'ou. Should you have any questions concerning this report or require fi.rrther information, please do not hesitate to contact our ofTice at (360)-676-9589 or :; (800)-859-5597. Sincerely yours, ' w. D. PURNELL & ASSOCIATES, INC., AN TJ-^\? u-t"^ P.E.G.Robert P. Bailey, P.E. Civil EngineerProfessional Engineering Geologist ---Atiachments: Site Plan USCS Soil Chart Test Fit Logs RB:bb ETHRES 11/21l I 11.E W.D. PTJRNELL & ASSOCIATES, INC.ll FI LE:95046 E.9il S L,COC EO. RPT Subject Bottom of Bluff ?( r oP e rtpv TP-4 tl B- TP_3 gt eu ?;fs:;'vw-: o B-4 TP_2 OB-s B-zzO TP_ 1 ApproximoteTop of ErodedBluff Moteriol +,u !O" \N ,,<\_<\ 6'crb %t ( GRAPHIC SCALEMw-# or B-#O rP_# o = Previously lnstolled Well = Test Pit Excovoted 4/25/97 2502550 100 (rru rrn) Site plon token from tooooroohic survevby Fokkemo & Kingmo, 'lni. 'Ook Horb'or, WA I INCH = 50 FEEI .!a tF.!95046e.97 oEotlD tt:RPB oi^ra 3fi RPB APPROXIMATT TTST PIT LOCATIONS MASSEY COMMERCIAL SITE PORT IOWNSEND, WASHINGTON olco(q, tr'!lEB CONSULTINO ENOINEERS'Odr6 r Qlyg . Orhbbd . Elvfnmrul F.8 ltaol At'&.tz' ltll Hr-loLr SanP.o. 8cr ltlaEollrrr|.r IVA $rtt l'-5O5tt/97 u IVA OAIE :cr{-e E Key to Test Plt Logs Uolng theUnified Soll Cjlassiflcutlon Systom5tt I t95CONSULTINO ENOINEENSkbdr r cl"I . O*14d. !|ftux.dtL X.-bUt lra?.O. t r llLl.uqb+ rA t,!tt\ oaat a?a.t.tat r 1160l t?&lataTfPICAL DESCRPIIO}Fwftt -GR^Dto ctrAvtts. cR^wL-s Ho!rnuR$. uInE oR }lo ftNtsPOOfi tY-GMOto cR^\rtls. CM\rtL-salo uxrunEs. unLt ofi M,nffisSfl,r 6R !,tts.MXn RfScnAV&-s^lt0-$_rcr ifY cR wLs. 6R^vtt-sxo-ct^r!0nuRtsrtfrl- GRTDIO SA|oS. OR^VtttYS^NDS, Utru OR }lO nNtSPOORTY-CR^DEo Sltos,srfios. umE oR NooR^lrtuyfiNtSs[rt S^NDS. S^tD-gLl rD(lwtscr,^YF 3^rD5, s^lto-clAt uxnRESlNo8c$nc s[ts Alto vtFY flNtsqos. Rocx ltoun 911y 9xcllYEY nM S^flDS tO CtAYfas[.ts rllx srE]tY P(Ancorlloqc[rc ct Ys oF lon to ltto0uPtrslrcllY, CR vfrlY cl"rYs_s^fiD/ cr,^Ys, si,r crlYs.'lErltct^Ysonc rJc s{,ls All0 0R6^]rc slLTYqlYs of Lof PusrrnrNORCI}TC Strts. ucrctor,s 0RDAIOllACIOi,s ftNf SAO ORsi"r so(sl}lm6a&c curs of lxcil. pusncrY. f^t crrY3oRc^l0c ct^YsPt.^silctr,of lfoura tooRGrlIc st-rsHICHPEAr. ]IUMUS. STVA{P SOttS nrHhlcfl ORG^fltC Co.rtBtrsLETTEBStxaq-GWGPc$/GCswSPSMsclfl-CLOLlvlFlCHOHPTGflAPHsY1€OLlittlititiMA"I)R DMSTONSCLEAN GRAVELS(umt oR ltoftlrts)<5tGRAVELSWTH FINES(lPPRECuart ^!ouMor |llltsl<t 2rCLEAN SANDS(trmt oR xoftNES)<5rSANDSWIH FINES(^PpRtcuaf arouMof n&s)<t2rSILTSANOCLAYSuo{Jro tutrlfs rlr N 50SILTS^lIDCLAYSllQ'JO lull!8fdIE nuil 0oHIGHLY ORCANIC SOILSGMVELANDGMVELLYsorLsl{,nt fi^r{ 501 ofC(uAST FilCIbNSIIAdID o{tlo. t smEsAr.l0ANDSANDYsorLsrrcnt l}l^N 50t ofco^Rst Ffi cmilfasrHc [o. Isf\{COARSEGRAINEOSOILSl{rrt rHAx got ofurtRr^r. s u6i!lItuN ro. 2dglt StZtFINEGRAINEOsotLsrsat tlsa tol ofultFrar 6 gtArEIlr x r{). .26gtvt &rtUNIFIED SOIL CLASSIFICATION CHART (USCS)GRADATION CHART. U.S. STANO fiO r CLEIR SeTARE OpENtltCS5-122 FTNES (S|LT & Ct y) ouAL CLASSSTRENGTH OF CLAY SOILSPARTICLE SIZEUPPTR IIMrIsrf\tr stztfro rlro tl1 ,J/( of,rIto1,ll LrMEttRso.422.004-76r9t762JO{.E9 1.1./tLOWER LIMITsrEvE stzElzoo tlrc,fto rl+,J/1' .f,rItrr.iltUrrEI€Rs.07{o.{22.00{.70r9t76.2JO{.tMATERIAL SIZESANORNEMEDIUMCOARSEGRAIELFINECOARSECOBBLESEOULDERSUnconfined CompressiveStrength(tonslsq. tt.)Consislency<0.25o.25 - 0.500.50 - t.oo1.00 - 2.002.00 - {.00>4.OOVery SoltSoftUedium SliJlsliIVory SlilfHord Table 1: TEST PIT LOGSTest PitNo.DepthInterval (ft)uscsSyrnbolSample #Depth (ft)MoistureContentDryDeruity1/2-inchIron BarPenetrationSoil DescriptionGPSPSPGPSandy CRAVEL parking lot topping(FrLL)Mottled grey-brown poorly gradedSAND with gravel (moisr,dense)(FILL)Brown poorly graded SAND wirhgravel (rnoist, loose)(FILL)GRAVEL with sund(moist, dense)6" by handr408.5-9.01.5-4.04.0-8.5Notes:TP-1 0.0-1.5rlTestletion of excavationbackfilled8'w/hammer wlsome difficultyStrong diesel smell at all locations in pitTest pit completed to 9.0 feet on 4l2Sl97l-1, 0.5l-2,3.5Brown poorly graded SAND withgravel (FILL)Poorly graded SAND with gravel(moist, loose, conc. rubble, claypipe)(FILL)Poorly grurled GRAVEL with sand(nroisl, nrcd rlense), 8'-12' logs @ 6'(FrLL)Poorly graded SAND with gravel(moist, med dense)7%2-1,2.5CPGPSP1.0-5.55.5-6.56.5-8.5GPNotes:TP-2 0.0-1.01o"7" 5"by handhole caving fromabove 5.5'2-2,8.42-3,9.OTest pit completed to 8.5 feet on 4+C44125t97Test pit loosely backfilled upon completion of excavationW.D. PURNELL ASSOCIATES, INC.TP-ISLCO.XLS Table I (Continued)TBST PIT LOGSTest PitNo.DepthInterval (ft)USCSSymbolSoil DcscriptionSarnple #Depth (ft)MoistureContentDryDeruity1/2-inchIron BarPenetrationTP-3 0.0-1.0OLBrown organic-rich SAND withgravel (moist, loose)(tOPSOIL)l.0-3.0SPBrown poorly graded SAND withgravel (moist, med dense)(FILL)3-1,2.5105l0' w/ hammerrather easily3.0-4.0SPDark brown poorly graded SANDwith gravel (moist, dense)(FllL)3-2,3.52' w/ hammer4.0-5.0SPBrown poorly gradul SAND withgravel (moist, med dense) (FILL)3-3,4.2512' wl hammerrather easily5.0-5.5SPBrown poorly graded SAND withgravel (moist, loose, wootl & wirerope, diesel smellXFILL)34,5.256" by hand5.5-8.0SPDsrk brown poorly graded SANDwith gravel (rnoist, med dense lodense)3-5,7.0 57o12' wl hammerwith some difficultyNotes:Test pit completed to 8 feet on 4125197Test pit loosely backfille<l upon completion of excavation2W.D. PURNELL ASSOCIATES, INC.TP-ISLCO.XLS Tuble I (Continued)TEST PIT LOGSDepth USCSInterval (ft) SymbolSample # MoistureDepth (ft) ContentD.yDeruityIron BarSoil DescriptionTest PitNo.1i2-inchTP-4 0.0-0.5OL0.5-4.0SP4.0-6.0SP77.O-9.sDark brown organic-rich SAND withgravel (moist, loose) (TOPSOIL onBluff slope)Brown poorly graded SAND withgravel (moist loose)4-1,2.5Brown poorly graded SAND withgravel (rnoist, dense,tank platformfootings)Surrounding Ground SurfaceBrown poorly graded SAND withgravel (nroist, dense, platform .footings)Brown poorly graded SAND (moist, 4-2,9.75loose)SPSP6%6' by hand9" w/hammer w/some difficulty9'w/hammer w/some difficulty7' by hand9.5-10.5Notes;Test pit completed to 10.5 feet (3.5 feet beneath lhe surroun<ling surface) on 4125197Testbackfilledon ofexcavationtl3W.D. PURNELL ASSOCIATES, INC.TP.ISLCO.XLS