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HomeMy WebLinkAboutPermit Field Test & Inspection Report 2004-9-20 SIP-20-2004 ~2:Slpm Frcm-K & A Enlln"rIRI, Ine \&bt ~ O~~(cL CJ\ +541-B84-8358 T-735 P 002/00T F-952 ~ a ,n9,,,,er'"; K I A Engineering, Inc. P.O. BOI28&24, Eugene, OR 87a 521 M1rb18L, Suite B. Eugene. OR 17. (&41) ..... Voice (&41) 11114-8368 FAX september 21, 2804 Hayden Homes 2464 5W Glacier Pllce, SuIte 110 Redmond, OR gn5S SUbject: Quality assurance - house foundatIOn pad Construotion Jasper M6adows SubdMsion - 2"1' Addltlon Springfield, Oregon Pmjecf: 74.04 PURPOSE AND SCOPE As 1'8qU88t8d. K & A Engineering. Inc, has complet8d mDnrtor1ng tfle constructfon of IndMduaf foundation pads , at the subject new residentlal.Ub6IV18Ion. 39 indMdual foundation pads were canstrucf8d at the site and prepared ready tor 1mmIng naw foundaUons. ' ,,< PrIOr to con&1JUOtion. a Geotechnlcallnverigation1 was made of the subdivision to develop specific f8Commsndatlons for developfng ttI8 slt810r IISIdent181 foun~atlonsr~' and UU1lt18s. The purpose of our 'lIYices was to provkle monftOl' construction of foundation paas to as&ur8 that conGtnJo1ion cl1t8rla OUIIIned In the geotachnlcallnvestlgation was addreSaed. . 11lI8 report documents foundation pad construction and makes recommendatiOns for suitability for residential foundation c..j~L JCIIon. fOUNDA11ON PAD EXCAYAnON 6MBI'll The foundltion pads developed for this project are to support conventionally framed ruidBntial 8InrotUI'88 cuppol11ld by convsntlonal cast-ln-pIace conCMB SprBad footings. Due to the slope or 1118 Site most of the foundlltion pads WlI1 constructed In two or more benches, separated In grade by approxima:lely 1 to 2-f8et. FouncI8Uon hill l11e Geotechnlcallnv88tlgaUon (BoIre) had predicted that high plasticity "Its or clays would unde~1e the site. Excavation for the padS conftrmed that in most of the foundation pads, 1here was 1 to 3-feet of a gray, highly plilStic, modBrat8Iy atIff'. and moist silt. In some locations the gray 8I~ contained a signlffcant amotmt of sub- rounded Ign8oU8 cobble$, ThIs silt was often covered by 0.6--10 i,D-feet of damp, very 1ow..cJens1ty peaty siltS. Weathered )'IIIIoW-tan tuffaceous siltStone or sandstone was encounterod uFldemeath the plastic sills. 1 BOlte As$OcIates, Inc., Ga, ~" .[nIcaIlnvesIlgallon for lie Jasper Meadows Second Addition, Springfteld, Oreoon. fIbnJIry 16, 2003, 8 'd ZEL9'oN S3~OH N30AVH ~dH:Z 900Z 'g 'uBf $ep-20-2004 02:31pm From-K & A En,lneerlni, Inc. +S41-GB4-D35S T-735 P ODS/007 F-9S2 K & A ERalneerfng, Inc. The gray pJaatic: iIIts and gray plastic tlllt8 with oobble8 were deepest through the western portion 01 the subdivision. IsoIatBd zones of gmy plastic silt Dr plastic silt with cobbles Will also encount8l'8d throughout the centJaI and eastern portion! at the eubd/vlslon. faumblliaD Pad Gonllrllcllon , Because 1he depth and lD4ent of solis varied significantly across the subdlvl~lQn, .,aoh pad was evaluatecl IndIVIdually to d*""Ra ttre proper depth of excavatioo and the amount 01 select 110 to be placed in the excavation. For many C1f th" foundation paela, the depth to weathered slRstone or sandstone was less than 2.feet and, In these cases, the foundation pads were excavated to bedrOCk, and graded smooth, level. and free from loose materfals. In ~ casas the base or tJ1e excavation was in two benches separDd in grade from 1 to 2-f6et StIlet aranular fill wu placed In the prepared excavation and brought 10 footing grade. In those areas of '*Per aray plastic sUI, the sifts were removed to a minimum depth of 1 &-inche8 below fooUnu gtade. The battDlTB of the excavations were gJlded smooth, level, and free from loose mate~als. In most cases the _ of the mccavatIon waa In two benches Separated In grade from 1 to 2-fael Select granuf8r no was placed in iha pttpat'Qd axcavatlon and brooght to footing grade. In all Ci$eS where peaty slits were encountered, the peaty-sUts were completely removed frOm the foundation aru. SIleOt 8I'InUIar Fills Select granular fills consisted or a BUb-base matertaJ and a baSe matertaI. The SCJb.obue matlriaI was Placed on the pt8f)8IId subgrzde in the foundatton pads and con9Itt8d 01 a S-1nch ITIInUs weu..gradQd quany 19911gata. The blee mat8rIaI was placed over the sub-iJase rock and consl8tBd of a 1 *Inch minus denae.graded quarry aggr8g8le. Both aggregates were produced at the Morse Bros. Quany In Springfield. l11a aub-ba88 ttioImIu generallY ranaed tram 6 to 12-inche8. Base rock ranged from 4 to 12..tncheS In 1hfokne8a, In a fvw GutS (bt8 33 ttJrvuQh 39) the sub-ba8e rock was eliminated and base rock was used exclU9/V11y for the islect gfWlUlar flU. The select Granular fills W8I1 well compacted in 12-inch maximum lifts (loose) using a steel-wheeled vibratory roller. Water was applied 88 necessary to maintain optImUm water contant during compaction. DenIIty Gf 8111c1 0rImI1ar FIlla SUb-base llle density of the sub-base was evaJuatBd by InSpection Of placement methods and fleld evaluation of water content. The denslly was considered ~daquate If passes by the large vibratory stael-drum roller did not I8ave YisIbIe marks In the sub-base aggr1girtB at th8 edges of 1he drum Bnd if the soil waler content appeared to be near optimum as determined In the field. e 2 SqU862lng a small amount of 118 liner aaaream in the hand did not produce sillJlificant free water and would r8ma1n In a rellliYely unIfonn ~ witIGUt imIYl8dIateIy 1aII1ng apart. Project 74.04 Jasper Meadows Subdivision Phase II, Sprff1gfieJd, OR Client: Hayden Homes Page 2 of 3 september 20, 2004 V 'd 68L9'oN S3~OH N30AVH ~d9v:6 9006 '9 'uer