5121 CHINOOK DR 2016-01-01 MF Import

Thomas Jones JN 4EOS0 March 14, 1 O90 Pps 2 The borinpa wsro drllled on January 18, 1990, uainp a Wdc-mounted, hollow-atem auper drfll. Samples wers taken at 5-foot intervals with a standard penetratlon sampler. This aplit-spoon eampler, which has a 2-inch outside diameter, is drtven into the soil with a 140-pound hammK falliny 30 inchea. The number of blows requfred to advancs the sampler a piven distance ia �n indfcatlon ot the soil density or conaistancy. A peotechnical enpinaer from our ata(f obaerved the drillinp proceas, loypad fhe teat borinps, and obtained roproaentativs aamplea of �e aofi ancountered. The Test Boriny Logs are attached as Platss 7 throuqh 9. Our tsat pita and teat borinpa revealed ftll depths of 3 and 11 fest on Lot 11, 4 and 15 feet on Lot 11, 12 and 17 feet on Lot 12, and under 4 faet on Lot 13. The flll on the lota contiats of aliphtly ailty to ailty sand wkh silt Some of the flll contains concrote debds, orpanic m�terial, end wood debris. Lots 10 and 11 contain beMreen 3 and 15 fest ot otd 8il overtyinp looae to medium-denss aand and a(Ity aand. Llkewiae, Lot 12 appears to be auRaced with about 12 feet of pll. Undertyinp the fiil and old topaofl, we encountered looae, ailry, fine-prained sand and ailt overlyfnp denae sand and ailt to tha maximum explorad depth of 29 feet. I The flnal lops ropresent our interprotaUona of the field lopa end laboratory teats. The aVaUftcatlon Iinea on ths lopa ropresant ths approximate boundariea between aoil lypsa at the exploratlon IocaUone. Ths�ctual transidon belwsen soll types may be�radual, and aubeuAecs conditlons pn vary between exploratlan locatlona. The lopa provids speciHc aubsuRacs intortnatlon only at ths Iccadone te:ted. The rolative denai8es and moiaturo deealptlons indicated on the test hole lops are interprotive descripUona based on the conditlona observed durinp excavaUon. The compactlon of backflll was not in the acopa of our serv(cas. Looee aoil wili therefore be found in the area of the test pits. If this prosenta a problem, the back}ill will need to be removad and replaced w(fh structural fili durinp conaUuction. (3roundwatsr Perched yroundwater saepaye was obsarved in Teet Pft 8. Th� Mst holea wen IsR open for only s ahort tlme period. Therofore, the ssepaps levsla on fhs loya nproaent the Iocatlon of tr+msf�nt weter esepaps and may not Indicete ths ataUc proundwater level. It should bs noted fhat qroundwater levels vary aeasonally with rainfall end other factors. We anticfpate that yroundwahr could bo found In more permeable soil layers and beNveen ttie near•aurfaca, weatherod aoU artd the undertyiny danser sofl. CONCLUSIONS AND RECOMMENDATIONS (3�neral The consUucUon of resfdences on the four lots eppeara to be feeeible trom a peotechnidl standpoint. However, aue to the dapth of the exisUnp Ril on Lots 10, 11, and 12, we rocomm�nd aupporUng the homes on these lota on deep foundaUon systsms that extend down to th� competent, naUve, silty sand. Drilled concrete piers or driven pfpe piies are probably the most economical deep foundatlon systems. Oue to the wet, loose till, the casing of aome of the drflled pien would probably bs necessary. To prevent crackinp and settlement, the Ifv(np apace alabs ahould be atructurally OEOTECH CONSULTAMa,INC