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Home My WebLink AboutPermit Field Test & Inspection Report 2005-6-20 Jun-20-2005 06,50pm From-K & A Enllne6rlnl, Inc +54; -68H358 T-ZEG P 002/004 F-i48 <<3" " . ..ngln~frlng K " A Engineering, Inc. P.O. Box 23624, Eugen., OR 87402 521 Martel St., Suite B, eugeRe, Oft 91402 (1541) 684.1890 Voice (841) 684-1368 FAX JURa 20, 2005 Scott Jordan 3520 Celeste Way Eugene, OR 97108 Project: 118.05 Subject: Foundation Soils 277 S. 6711l ct., Sprlngfleld, OR Springfield Permit No. COM2005-00619 PURPOSE AND SCOPE As requested, K & A Engineering, Inc. has completed a limited evaluation of tt1e foundatIOn salls at the subject project site, Our understanding is that a new conventionally framed single-famify residence supported by a cast-in-place concrete spread footing foundation Is proposed for construction at the site The purpose of our investigation Is to prOVIde recommendatIons for foundation beating at the site wJth respect to expansIve soils, bearing capacity, and draInage. iNVESTIGATION AND FINDINGS GUlrel Surface Conditions The prOjtlct site located at the end of a cul.de.sac located in southeast Springfield. The lat slopes to the north (toward the street) at approximately 13%. The general arel! has had a mooeram vegetative cover consistIng of timber and light understory consisting of native and non-native shrubs We did not obs9IVelndlcatJons of slope movement such as scarps, slump.s, depressions, or tension cracks The trees on adjacent lots did not appear to indicate slgnl1lcant soil creep (bent trunks). We did not see surface seeps or springs. SUnsurtacfl Condltlona ExcavatIOn for the foundation resu~ed in a foundation pad at one elevation aut into 1he hdlslde with the highest cut nelght at approxImately 6-teet along the south sida. The cuts around the foundation pad diminish In height around the cut to a cut height of approximately 1-foot along the nortr, edge of the excavation. A second terrace was cut behind the foundation pad to aocommodate a yard, Cut slopes along the back yard cut are as high as approximately 8-feet. SOils exposed in the cut conslst.ot 1 0 to 1.5-(eet 01 dark brown organic silts (topsoil) over tall decomposed or highly weathered tuffaceous siltstone, The siltstone con1alns included rounded and subrounded large gravels and cobbles. Groundwater was not encountered In the excavation. J"~-20-2005 06:50pm From-K , A ~nilri.rlri, Ine +541-684-9358 T-2S6 P 003/004 F-748 K & A Engineering, Inc. Fl3undl1iol Pad Preparation After the pad was cut into the hlPside, the base of the excavatIon was graded smooth to undisturbed native sandstone. The undIsturbed sandstone at the bass of the exoa~ation was covered With approximately 3.inches of o/.-lnch nllnus crushed aggregate. SUMMARY AND RECOMMENDATIONS Benenl Aecommenddans The foundation pad, as prepared, will proIJide adequate bearing support of the foundation with a low to moderate hazard associated with soU expansion and excellent bearing capacity. The compaction of the granular fills is sufficient to provide excellet1t bearing capacity without slgnltlcant settlement The preparation of this foundation pad complies with the recommendations of GeoStandards.' We recommend acceptance of the foundation pad, as oOlJstructed, by the fDcal building official. Foundation Support We recommend a design allowable bearing pressure of 2,000 pounds per sQuare foot for oonventl0!181 spread strip W1d isolated footings. A concrete slab.,cn-grade is acceptable for the garage floor as long as footing drainage is installed as recommended below Expansive Soils The highly weathered or decomposed siltstone has a moderate potent!al for volume change with ch:mges In water content, We recommend that perimeter fcotrngs be located so that the undlsturblJd native decomposed siltstone IS Ii minimum of 24.lnchas below the fm3l grad8. Based on our obserilatlol1 of the exoavation and foundation pad grading these crltella stlould be easily m0t. Drainage Final grading should slope away from the pelimeter foundation. footlna drains should be Installed to Intercept possible groundwater around the entlra foundatIon, This drain system should consIst r;f rlgld perforated pipe covered with a minimum of 12-lncnes of dram rock that is wrappsd by separatIon gootsx!:ile. The perforated drain stltJUfd be placed so that the pipe along the SOUlll foundation rests at bas6 of the excavation at the same grade as tho rlstiv8 siltslone. Roof dralllage st10uld be well constructed to oollect all roof runoff aoo rolJte it to the street storm drain systam. SPEClFICA'f80NS Foundation Drain Partorated drainpipe should consist rigid ADS 3000 Triple Wall pipe The perforations should be placed ~own The foundatIon drain should NOT be connactoo to the roof drain unless the connection Is made downhill of the foundation utiliZing a backflow pr8V811t1on device that prohibits roof drainage from backing up Into the foundation drain system. , Geotechmcal E'I9ll.1allon Report1hecl wIth the City of Sprlnglle!d - "Proposed St. Lucia Place SubdiVision lot 12 through lot 18 Springfield, Oregon", GaoStandards Project No. E03.0165, GioStllndards (geotllchnicsleogmeer), June 11, 2003, PrOject: 118 05 Client. Scott Jordan 277 S 67th Ct., Springfield, OR Page 2 of 3 June 20,2005 .. JU:l-ZQ-200S Of.'51pl!I FrOI!1-K &. A Enilneerlni. Inc +5l;-aB4-9358 T-256 P 004/004 F-748 K a A Engineer/ltg, Inc. Drain Rock Drain rock should consIst 01 clean, durable, 1 Ve.inch round rock. The rock should be placed over and to the side 01 the pst10raied pipe so that the pipe has a IT1Inimum of 12-lnches of cover The drain rock should be coveraci with separation geotextlle Separation Geotmira Separation gaotoxtU9 should be placed on the grdde (at footing level) prior to plaoement of the perforated pipe so thBJt after the pipe Is laid and drain rock place. the geotextils Carl completely wrap around the dram rock, ~eparatlon geote.xtue shall consist of a polypropylenij non-woven needle-punched fabric tnat is stabilized against degradation from ultraviolet light e>;posurl:l (sunlight), The fabric should meet the specifications for Amoco Propex 4535. LIMITATIONS Of THIS REPORT This report has been prepared for the exclusl\le use of Jordan Construction and Its subcontractors for the subject proposed structure This geotechnlcal invElstigatlon, analysis, and recommendations meet the standards 01 care of competent geotechnical engineers provkllng similar servICes at the time these services ware proV1ded. We do not warrant or guarantee these recornmendat!ons, site surface, or subsurface conditions. Exploration test holes indicate soil cotlditions only at specific locations (I.e, the test hole locations) to the depths penetrated They do not necessarily reflect sOil/rock materials or groundwater conditions that exist between or beyond exploration locations or limfts. The scope of our services does not Include constructIon safety plecautlons, techniques, sequences, or procedUl'6S, excapt as speCifically recorrimended in this report, Our services should not be interpreted as an enVIronmental 88Sa8Sment of sne conditions. Tnank you for the opportunltlj to be of servlt:e, Please call us 11 you have questions or need furth8r assistance. Sincerely, ~:J'~ ~"'~~-'C'~~"",...... Michael Remboklt, P,E. K & A Engine&rlng, IrlC. eftAES l--A(vfr. I ProJect: 118.05 Client: Scott Jordan 277 S. 67t~ Ct., Springfield, OR Page 3 ot 3 June 20, 2005