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Home My WebLink AboutPermit Field Test & Inspection Report 2004-9-20 "J 'Lt~ Ofchtcllr\ $1P-20-20D4 ~2:Slpm Frcm-K & A Eniineerlnl, Ine +54H84-935& T-TS5 P 002/001 F-952 a 'ngln'erlng K" A Engineering, (nc. P.O. Bar 28&24, EDgene, OR 87402 521 MIrIcef Il, Salite B. Eage... OR .7. (141) __ Voice (141) 184-8368 fAX 8sptember HI 2fJG4 Hayden Horne!l 2464 SW Glacier Place, Suite 110 Redmond, OR 9n56 Subject: Quality assurance - house foundaUon pad construotion Jasper M4adows Subdlvlsion - 2nd Addltlon Springfield, OrtUon Project: 74.04 PURPOSE AND SCOPE AsI'8t1uested. K & A Engineering, me, has completed mOnltor1ng the coostructlon of Individual foundation pads at 1he subject new residentlalSUfJdlVl8lon. 39 individual foundation pads were construcf8d at the site and prepared readyforformfng new foundations. Prior to construotion. a Geotechnlcallnve5tlgation' was made of the subdivision to develop specific recommendatlons for developing 1tI8 alteror rlsldentl8l foun,datlons,~. and UUlltlas. The purpose of our allViceS \WS to provide monItOr constructlon of foundation padS to 8SSUl'8 that oonmmtion criteria otJtlIned In the geofsclmicaf Investigation was addressed. . 1l1Is report documents foundation pad construction and makes reoommendations for sullablllty for resldentllll foundation construcUon. .. FOUNDAllON PAD EXCAYAnGN Genn The founda:tion pads developed for this project an: to support conventionally framed resmllntial atnJctur88 tupportdd by conventfanal cast.fn-ptace cancrum $prBld footings. Due to the slope CJlIhs Sit most at the foundation pads'were constructed In two or moro benches, separated In grade by approximately 1 to 2-feet. FoundIdOII SOUl ll1e geOtechnlcallnve8tklaUon (BoIre) had predicted that high plasticity eJlls or clays would underU! the site. Excavatlon forb ptd8 confirmed that in most of the foundation pads, 1here was 1 to 3-feeI: of a gray, highly plastic, modllratlly atIff. and moist silt. In some IoeatiDns the gray sI~ contained a slgnlffcant amount or sub- rounded Igneou8 cobbles. This silt was orten covered by O.&.to 1.().feet of damp, very Iow..(fenslty peaty siltS. Weathered ydow-tan tutfaoeous siltStone or sandstone was encountered underneath the plastic silts. 1 BOIre ~ IRe,. G8OleChnlcallrw8slgallon for lie Jasper Meadows Second AdditiCII, Springfield, Oreoon, fIbnIary 16, 2003. , 8 'd l8L9'oN S3~OH N30AVH ~dH:l 900l 'g 'uer $1P-20-2004 02:31pm From-K & A Enilneerlnl. Inc. +541,,684-935& T-735 P 00S/007 F-952 K & A EJlalneerlng, Inc. The gray plastic 8IIts and gray plastic ~lIte with oobbles were deepest through the western portion of the subdivision. IsoIat8d 20008 of gray plastic silt or plastic silt wtth cobbles Wire also encountered throughout the central and eastern portions of the eubdMslon. FUlDluliDl Pad GonllnlctlOR Because the depth and m4ent of soDs vaned significantly across the subdlv~n, ~h pad was evaluated IndlYldually to detwmlne the proper depth of excavation and tile amount 01 select fin to be placed in the excavation. For many (If ~ foundafion pads. the depth to weathered slRstorm or sandstone was less than 2.feet and, In these case&. the foundation padS were excavated to bedrOCk, ane! gl'lded smooth, level, and free from loose materials, In IlWt casas the base or the excavation was in two benches separated in grade from 1 to 2.feet SeleCt aranular III WI8 placed In the prepared excavation and brought 10 footing grade, In those af!a of deeper gray plastic sUl, the sifts ware removed to a minimum depth of 1 &-inche8 below fooUno grade. The batlDms of the 8lCCMtIons were graded smootl'l, levsl, and me from loose mat8~als. In most cases the base of tho excavatfon was In two benahes sepamteclln arade from 1to 2-fset. Select granular no was placed in the pmparad QltCavatIon and broooht to footing grade. In all cases when! peaty slits were encountered, the peaty-silts were completely remavad frOm the foundation area. SGIeot CIrInuIar Fills Select granular fills consisted of a sub-base mater1al anti a Due material. The SlJb..buu matlrial was placed on 1h8 prepared subgrade in the foundation pads and con9lst8d of a S-Inch minus waU.grad8d qU8tl'y aggragatB. The bQe material was placed over the sub-J>ase rock anti conslstBd at a 1 *Inch minus denaellraded Qll8lTY aggr&gat9. Both aggragates were produced at the Morse Bros. Quarry In Spr1nahe1d. 1l1a 8lJb.basG thiOIa1ISS generallY ranged from 6 to 12-inches. Base rock ranged from 4 to 12oo1nches In 1hICJcneaa. In a few Goes (Iot8 33 through 39) the sub-ba8e rock was elimInated and base rock was used exclUslv8Iy for the ielect granular fill. The select granular fills were weD compacted in 12-inch mmdmum lifts (loose) using a steel-Wheeled vibratory roller. Water was applied 18 necessary to majntain opflmUm water content during compaction. DIIIIIly III 811ec1 Bnmular filla ~ The denstty of the sub-base was evaluated by inspection of placement methods and field evaluation of water content The denslly was considered adequate If passes by the large vibratory stael-drum roller did not I8ave vtsJble markS In the stJb.ba&e 8gg~ at the edges of the drum and if the eaR water cont8nt appeared 10 be near optimum 8S determined In the field. II 2 Squeezlng a small amount of 118_ aalJJ8ual8 in the hand did not produce BilJllificant free water and would f8ITI8fn In a . "/"I~'.Jy uniform baJ wtIKIut immediately failing apart. " Project 74.04 Jasper Meadows Subdivision Phase II, Springfield, OR Client Hayden Homes Page20fS S8ptamber 20, 2004 V 'd G8L9'oN S3~OH N30AVH ~d9v:G 900G '9 'uer