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HomeMy WebLinkAboutPermit Field Test & Inspection Report 2004-9-20 . ~ w'O~'uJ ~eb'D\G ~ SIP-20-20D4 ~2:9Ipm Frcm-K & A Enllneerlnl, Inc +541-884-9358 T-7S5 r 0021007 F-952 a 'ngln'IHlng K I A Engineering, 'nc. P.O. 80128624, E....... OR 87a 521 MI. Il, Suite B. !up.., OR 17. (541) I84-8a8I Voice (141) 184-8368 FAX September 28, _ Hayden Homes 2464 5W Glacler Piece. SUb 110 Redmond, OR 97758 Subject: Quality assurance. house foundation pad construotion Jasper Meadows SubdMsion - 2nd Addition Sprfngfl8ICI, Oregon PrajeId: 74.OC PURPOSE AND SCOPE AsI'8quested. K & A Engineering, Inc, has complet8d monrtortng the consbuctlon of Individual foundation pads at 1he subject new residentlalaU!K!M8Ion. 39 individual foundation pads Wlrt construcl8d at the site and prepared ready for fonnJng new foundaUon$. Prior to construotion, a Geotechnlcallnverigation1 was made of the subdivision to develop specific f8Commsndatlons for developing tile site for I'Isident181 fou~atlons,~. and UlBltl8s. ltt8 purpose Of our IIBJVices was to provide monitOl' construction of foundation paas to as&llr8 that conatruotion crftetla outlined In the geotechnical Investigation was addr8Saed. . 1111s report documents foundatlon pad construction and makes recommendatiOns for suitability for resldentllll foundation construdIon. FOUNDA'OON PAD EXCAYAnON GBllBI'II The foundation pads developed for this project an: to IiUpport conventionally framed residential atnICtul'88 supported by conventional cast..jn-place conCRlte spread footings. Due to 1he slope or tI18 SIt8 most or till foundation pads were constructed In two or more benches, separated In grade by appraxilTJlltely 1 to 2-fllet. FeundIdOD saill ll1e Geotechnlcallnve8tlgatlon (Bofre) had predicted 1hat high plasticity slits or clays would underUe the site. Excavation forb pad8 confirmed that in most of the foundation pads, there was 1 to 3-feet of a gray, hlgtdy plutic, moderallly BtIff. and moist slll In some Ioc:ations the gray sI~ contained a significant amount: of sub- rounded Ign8OU8 cobbJe$, This silt was orten covered by 0.&.10 1.Q..feet of damp, very low--denslty peaty siltS. Weathered ydow-tan tuffaceous siltstone or sandstone was encountonKl underneath the plastic sills. 1 BOIre AsaOcIatBs. Ine" G~,:",,_[ .nIcaIlnvesIgaIlon for tie Jasper Mladowe Second AdditiCII, Sprlngfteld, Oreoon. FtbnJary , 6, 2003. 8 'd 28L9'ON S3~OH N30AVH ~dH:2 9002 '9 'uer ,~ , $ep-ZO-Z004 02:31pm Frum-K & A En"neerini. Inc +S41-GB4-me T-735 P 009/007 F-9S2 K & A Engineering, Inc. The gray plastic slits and gray plastic -ullta with oobbles were deepest through the westem portion 01 the subdivision. IsoIatBd zones of gray plastic sltt or plastic silt wtth cobbles wtIl1 also encountered throughout 1he cerrtJal and eaatem portions at the eubdlvlsfan. Faundllian Pad ConllrlclloR Because 1he depth and extent of soDs vaned significantly across the subdlv~lQnJ .,ach pad was evaluated IndMduaOy to determine the proper depth of excavation and tile amount 01 &elect nn to be placed in the excavation. ' For many t1f tho foundatiOn pad8. the depth to weathered slftstone or sandstone was Jess than 2..feet and, In Iheso cases. the foundatiOn pads were excavated to bedrOCk, anCf graded smooth, level, and free from loose materials. In ~ C8$8S the base or the excavation was in two benches separal8d in grade from 1 to 2.feet select aranular fill wu placed In the prepared excavation and brought to footing grade. In those areas of deeper aray p1astlc sit, the silts wars removed to a minimum depth of 1 &-inche8 below fooUnu grade. The battolTl$ 01 th9 excavatlons were grnded smooth, level, and free from Iaose matBrlals. In most cases 1he base of the mccavatJon W88 In two benches separated In grade from 1 to 2-f8el Select granular fin was placed in the ~ axcavatlon and brooght 1D footing grade. In all cases where peaty slits were encountered, the peaty-slits were completely remavad frOm the foundallon area. SGItOt CIr8nuIar FilIi Select granular fills consisted of a sub-base matertal and a baSe material. The SlJb..bua mabnjaf was placed on 11\8 prepared subgrade in the foundation pads and consrstBd of a a-tnch mlnUc weU.gradld quany aggragat8. 'The baGe material was plac84 over the stJb.i>ase rock anti consl81Bd of a 1 ~nch minus dense-oraded quarry aggregal9. Bo1h aggr1Q8teS were produced at the Marse Bros. Quany In Sprlng1leId. 1110 stJb..basG tf1iCkneIS generallY ranged from 6 to 12-inches. Base rock ranged from 4 to 12-1nches In 1hIckneas, In a fvw aoes (Iot8 33 through 39) tf1e sub-ba8e rock was eliminated and base rock was used exctuslv8ly for1he uIect granular flU. The select granular fiUS were well compacted in 12-inch maximum lifts (loose) using a steel-wheeled v1~ ~t J roller. Water wu applied 88 necessary to maintain optlmUm water content during compaction. DenIIty or ..... Onnmlar RIll SUb-base The densfty of the sub-base was evalUated by InSpection of placement metI10ds and fleld evaluaUon of water content. The denslly was considered adequate If passes by the large vibratory stsel-drum roller did not f8ave visible markS In the stJb.base aggrqm at the edges of the drum Bnd if the 80iI wal8r contBnt appeared to be near optimum 88 d8tennIned In the field. a 2 Squeezing a small amount of 118 ftn8r IOlJJ8Uall in the hand did not produce silJflfficant flte water and would r&maIn In a relllMly uniform ~ .out immediately failing apart. Project 74.04 Jasper Meadows Subdivision Phase II, Springfield, OR Page 2 Of 3 Client Hayden Homes September 20, 2004 t 'd lU9'oN S3~OH N30AVH ~d9t:l gOal 'g 'uer