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Home My WebLink AboutPermit Field Test & Inspection Report 2005-4-4 Apr-04-2005 06.27pm From-K & A EnSlneer Ina, Inc +541-684-9358 T-07i P 0021002 F-523 r -a .ngln..rlng K & A Engineering, Inc. P.O. 80x 28824, Eugene, OR 07402 521 Market St.. Suite I, Eugene. OR 97402 (541) 684.9309 VolGe (541) e84~83Q fA){ AprtI4.2005 Scott Jordan 3520 Celeste Way Eugene, OR 97108 Subject: Foundation Soils 288 S. 67111 Ct . Springfield, OR Springfield Permit No. COM2005-00198 Prqect: 22.06 PURPOSE AND SCOPE As requested, K & A Engineering, Inc. has completed a limited evaluation of the foundation soils at the subject project site, Our understanding is that a new conventionally framed single~famlly residence supported by a cast-in-place concrete spread footmg foundation Is proposed for construction at the S~ll Ths purpose of our Investigation IS to provide recommendations for foundatIon bearing at the site with respect to expansive soils, bearing capacity, and dralnage. I INVESTIGATION AND FINDINGS General SUrlaCI Conditions The prOject Slt8 located at the end of a cul-de"sac located In southeast Springfield. The lot slopes to the north (toward the street) at approximately 15%. The general area has had a moderate vegetative cover consisting of timber and light understory consisting of native and non-native shrubs. We did not observe Indications of slope movement such as scarps, slumpS. depreSSions, or tension cracks The trees on adjacent lots did not appear to indicate SIgnificant soil creep (bent trunks). We did not see surface seeps or springs. Subsurface Conditions Excavation for the foundation resulted In a foundatIon 'pad at one elevation cut into the hillSide with the highest cut height of approxImately a-feet along the south sIde. The cuts around the foundation pad diminish in height around the cut to a cut height of approximately 1.foot along the north edge of the excavation. Solis exposed In the cut oonsist of 1 5 to 2.0-'86t of dark brown organlo sms (topsoil) over tan decomposed or highly weathered tuffaceous siltstone. The slnstone contains 1.0 to 2.0.foot layers of included rounded large gravels and cobbles. Groundwater was observed at a depth of approximately 3.0-f8et. Apr-04-Z0C5 06:06pl!I Frcln-K & A En,lr.eerln" It'c r +541-684-9358 T-070 P 003/004 F-620 K 6 A Enginollrln.. Inc. FlIlullIdatiotl Pad Pr8parldoB After the pad was cut Into the hUlsid9, the base of the excavation was graded smooth to slops to the north, with a drop of approximately 1-foot. Approximately 6 to O~lnches of 3-inch minus poorly-graded silty-sanoy crushed quarry rock was placed on the north half of the foundation pad and compacted using a vibratory steel drum roller App, ",,;~ "ately 3-lnches 01 %.Iflch minus dense graded crushed aggregate was placed on the entire foundation area and compacted. SUMMARY AND RECOMMENDATIONS eeneral Rec:ommddut.ona The foundation pad. as prepared, Will provide adequate bearIng support of the foundation with a low to moderate hazard associated With soil expansion and excellent bearing capacity. The compaction of the granular fills Is sufficient to prolflde excellent bearing capaCity without slgnlflcant settlement. We recommend acceptanlle of the foundation pad. IS constructed, by the local building official. Foundation Support We recommend a design allowable bearing pressure 012,000 pounds per square foot for convilntlonal spread strip and Isolated footings. A concrete slab-onugrade Is acceptable for t~e garage floor as long as footlng drainage Is installed as recommended below. . ExpensJve Solis The highly weathered or decomposed siltstone has a moderate potential for volume change with changes In water content. Wa recommend that perimeter footings be located so that the undisturbed native decomposed slltston~ Is a minimum of 24.inches b9low the final grade. Based on our observation 01 the excavation and foundation pad grading these criteria should be eas!!y met Dralne;e Final grading should slope away from the perlmater foundation. Footing drains should be Installed to Intercept possible groundwater around the entire foundation. This drain system should consist 01 rigid perforated pipe covered w~h a minimum o112.lnches or drain rock thai Is wrapped by separation geotextlle. The perforated draln should be piaced 80 that the pipe along the south foundatlofl rests at base of the excavatIon at the same grade as 'tt1e native siltStone. Roof drainage should be well constructed to collect all roof runoff and route It to the street storm drain system SPECIFICATIONS Foundation DraIn Perforated drainpipe should consist rigid ADS 3000 Triple Wall pipe. The perforations should be plaCed down. The foundation drain should NOT be connected to the ro01 drain unless the connection is made downhill of the foundation utlllzlng a backflow prevention deVice that prohIbits ro01 drainage from backlOg up into the foundation drain system. Drain Rock DraIn rock should consist of clean, durable, 1 V2.lnch round rock The rock should be placed over and to the side of the perforated pipe so that the pipe has a minimum of 12-inches of cover. The drain rock should be covered with separa~n geotextilea Project: 22.05 Client: Scott Jordan 288 S 67th Ct., Springfield, OR Page 2 of 3 April 4, 2005 Apr-C4-2005 OS,38pm From-K & A Englneerln., Inc +541-684-9358 T-07Z P 004/004 F-5Z7 'J K & A EltgilllJering, life. foundation utilizing a bacl<flow prevention device that prohibits roof drainage from backing up Into the foundation drain system. Drain Rock OraJr: rock shoUld consist of clean, durable, 1 l/a-inch round Tock. The rock should be placed over and to the side 01 the perforated pipe so that the pipe has a mlnlmtJm of 12-lnches of cover. The drain rock should be covered WIth separatIon gtlotextRe SeparatIon Geotextlfe Separation geotextlle should be placed on the grade (at footing level) prior to placement of the perforated pipe so ttlat aftar the pipe Is laid and drain rock place, the gaotaxtlle can completely wrap around the drain rock. Separation geotextlle shall ConSist of a polypropylene non-woven needle-punched fabric that is stabilized against degradation from ultraviolet light exposure (sunRght). The fabric should meet the specifications for Amoco ProPex 4535, LIMITATIONS OF THIS REPORT This report has been prepared for the exclusIVe use of Scot Jordan and his designer consultants and subContractors for the SUbject proposed structure. This geotechnlcallnve8tlgation, analysis, and recommendations meet the standards of care of competent geotechnical engineers providing SImilar servICes at the tIme these services were provided. We do not warrant or guarantee these recommendations, site surface, or subsur1ace conditions, exploration test holes Indicate soli conditions only at speclflc locatiOns (I,e. the test holalocatlons) to the depths penetrated. They do not necessarily reflect solVrock materlals or groundwater condtt1ons that exist between or beyond e,xploratlon locations or Ilm~s. . The scope of our services does not Include construction safety precautions, techniques, sequences, or procedures, except as specifically recommended In this report. Our services should not be interpreted as an environmental assessment of site conditions. Thank you forthe opportunity to be of service. Please call us if you have questions or need further assistance. Sincerely, " .' ~--~, Michael Remboldt, P.E K & A Engineering, Ino ~ 'f>>'IIB tLff)f &.. - , Project: 2Z,05 Client. Scott Jordan 288 S. 671~ Ct., Springfield, OR Page 3 of 3 April 4, 2005 f '<~":: ::'!~) Apf-04-2005 06 :06pm ,~\_.:/~j r1 ~ iy........ · ,;.& . Frcrn-K & ~ El18,naerlns, Int +541-684-9358 T-070 P C04/004 F-52D K 6 A Engineerlng, Inc. ....' ~ ~ , . ~ . " . " . . , Separation Geotex1ile ~p'aration gaotextile should be placed on the grade (at footing level) prior to placement of the perforated pipe so that after the pipe IS laid and draIn rock plac9, the geotextile can completely wrap around the drain roc 1<. Separation geotextlle shall consist of & pOlypropylene non-woven needle-punched fabric that is stabilIZed against degradatlon from uKravlolet light exposure (sunlight). The fabric should meet tns specJrlcatlons for Amoco ProPel< 4535 ~~ f. LIMITATIONS OF THIS REPORT This report has been prepared for the exclusive use of Scot Jordan and hiS designer consultants and sLlbcontraC1ors for the sUbject proposed structure, This geotechnIcal Investigation, analysis, and recommendations meet the standards of cart! of competent geotechnical engineers providing similar services at the time these services were provided. We do not warrant or guarantee these recommendations, s~e sur1ace, or subsurface conditions. Exploration test holes Indicate _ soli conditions only at speCIfic locations (I.e, the test hole locations) to the depths penetrated. They do not necessarily reflect soiVrock materials or groundwater conditions that exist between or beyond exploratJon locations or limits. The scope of our 881\'Ie98 does not Include construction safety precautions, tecl'mlques, sequences, or procedures, except as specifically recommended In this report Our services should not be Interpreted as an environmental assessment of site conditions, Thank you for the opportunity to be of service. Please call us If you have questlons or need further assistance. Sincerely, EXPIRES hi., J L. I / Michael Rembold!. p,e, K & A Engineering, Inc. Project: 22 05 Client' Scott Jordan 288 S, 67~ Ct., Springfield. OR Pagll 3 of 3 April 4, 2005 .. , .~ >a '.