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HomeMy WebLinkAboutPermit Field Test & Inspection Report 2004-9-20 ~D~t \J{tO\~ Qk S,p-20-20D4 D2:Slpm Frcm-k & A Enflneerlnl. Inc +541-B84-8S58 T-735 P 002/007 F-952 a .ngln"rlng K I A Engineering, Inc. P.O. BOI28624, EGgen.. OR 174O! 521 MIf'bt Il, Suite II. EuIflH. OR 17. (&41) __ Voice (141) .... FAX September 21, 2fJ04 Hayden Homes 2464 5W Glacter Placo, Suite 110 Redmond, OR gn5fl SUbject Quality assurance. house foundation pad construation Jasper Meadows SubdMsion - 2nd AddlUon SprlngfISkJ, Oregon PmjeI:t: 74.04 PURPOSE AND SCOPE As 1'8qU98ted. K & A Engineering, Inc, has complel8d mDnltoring the coostrucUon of IndMdual foundation pads at the SUbJect new residantlalauoolVl8/on. 39 inDIVidual foundation pads WIt$ tgMftUCfBd at the site and prepared ready for fonnIng new foundaUons. Prior to construction. a Geotechnlcallnv~gaticn' was made of the subdivision to develop specific l8Commsndatlons for developIng ttI8 slt810r JlsldentI8I foun,datlons,~, and UtIUtIa8. The purpose Of our aBJVices was to provide monItOr constructlon of foundation padS to as&tJr8 that c:onatruution crlt8r1a otJtIIned In the ge0f8c1m1caJ Investigation was addressed. ' 1ht8 report documents foundatfon pad construction and makes reaamrnendations for suitability for re$kfentlal foundation construcIIon. fOUNDATlON PAD EXCAYAnGN GIIIBI'II The foundltion pads developed for this project are to BUpport conventionally framed residential atructul'88 supported by conventional cast-in-place conCl'fltB $pf'&ad footings. Due to 1he slope or 1118 Sb most of the foundation pads WGI'8 constructed In two or more benohes, B8par1ted In grade by apprmcLo ,(hly 1 to 2-feet. FountIIUGII SOill 1lIe aeoteclmlcaf lnve8tIQatIon (BoIre) had predicted that high plasticity slits or clays would underlie the site. excavation for the padS conflrmed 1hat in most of the foundation pads, 1here was 1 to 3-feet of a gray, highly plutlc, modsrat8ly stiff. and moist silt. In some locations the gray sift contained a slgnlffcant amount of sub- rounded Ign80uB cobbJe$, 111Is silt was orten covered by 0.&.10 i.D-feet of damp, very lowoodenslty peaty siltS. Weathered )'tIIlOW-tan tuffaceous siltstone or sandstone was encountGrud underneath the pIastIt silts. 1 BOfte AsaocIatBs. Ine" G~ 'J,41IolJca/ MdpllOll tor lie Jasper MeatJOWJ Seeond AdditiCll. SprtnQfl8Id. Oreaon. FtbnIary 16, 2003. 8 'd lU9'oN S3~OH N3GAVH ~dH:l 900l 'g 'uer S8P-20-2004 02:31pm From-K & A En,ln88rlnl. Inc +541-894-8358 T-735 P 0091007 F-9S2 K , A EJlgfneerlng, Inc:. The gray plastic sIItB and gray plastic ~11te with cobbles were deepest through the westem portion 01 the subdivision. loiAlw...d zones of gmy plastic silt Dr plastic silt wfth cobbles WlI1 a1SD encountered throughout the central and eastern portions of the eubdMslon. faumblliDD hd CoollruclloR Because the depth and m4ent of solis varied significantly across the 9ubdlv~lQn. .,ach pad was evaluated IndlYlduallY to determfne the proper depth of excavation and tile amount of select 1In to be placed in the excavation. For many of ~ foundatiOn pads, the depth to weathered slRstone or sandstone was less than 2..feet and. In these casas. the foundation pads were excavated to bedrOCk, and gilded smooth, level, Bnd free from loose materials, In ~ casas the base or the excavation was in two benches separDd in grade from 1 to 2.feet. select Granular fill WU placed In the prepared ma:avatIon and brought to footing grade, In those .,. of deeper aray plastic sUI, the sifts were I'8tTlOY8d to a minimum depth of 1 &-inche8 below footing grade. Tho battDmB Of th9 excavatlons were graded smoottl, level, and me from loose materials. In most cases the base of the exoavatIon was In two benches separated In grade tram 1 to 2-fael Select granular no was placed in tha ~ 8XC8VldIon and brought to footing orade. In aU cases where peaty slits were encountered, the peaty-slits were completely remavad frOm the foundallon area. IGIeot CIrImdar FilII Select granular fills consisted of a sub-base material and a baSe material. The ~bue . I "I: rial was plaoed on 1M prepaIId subglade in the foundation pads and COMfstDd 01 a S-Inch rn!nuI waU.grBd8d quany ~rogate. 'Tbe bQe material was placed over the StJb-I>aSe rock and con8l8tBd of a 1 *lnph minus densel1raded quany aggr&gate. Both aggreQ8t.eS were produced at the Morse Bros. Quany In Sprlngfleht llJ& sub-base thiOIalIII generallY ranaed from 6 to 12-inch88. Base rock ranged from 4 to 12-inches In 1hIokne88. In a few aUlS (Iot8 33 through 39) tf1e sub-bae rock was eliminated and base rock was l.IS8d exclUalv8ly for1he salect granular fill. The select granular fiUs WII1 weO comnacted in 12-inch maximum lifts (loose) using 8 ste8i-Wheeled VIbratory roller. Water was applied 88 necessary to maintain optImUm water content during compaction. DenIIty cd 811cc1 0rInu1ar filii SUb-base The density of the sub-base was evatuatad by InSpection of placcmmt methods and fleld evaluation of water content The denslly was considered adequate It passes by the large vibratory 8tsekJrum roller did not IBM , visible markS In the stlb-base 8gg~ at the edges of 1he drum BJ1d if the 80iI waler content appeared 10 be near optimum 88 determined In the field.' 2 SqueezIna a smafI amount at lis liner IOQf8O'ld8 in (he hand did not produce siDJlfficantfree water and would I8Il'IaIn In a relllively unIfonn btJI wtJKJUt imm8dIateIy failing apart. Project 74.04 Jasper Meadows SUbdivision Phase II, Springfield, OR Page 2 of S ClI8IJt Hayden Homes september 20, 2004 V 'd 68L9'oN S3~OH N30AVH ~d9v:6 9006 '9 'uer