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Home My WebLink AboutMiscellaneous Field Test & Inspection Report 2011-2-1 . "j ; ';'lFeb 8. 2011 9:20AM d '.'. ~ K&A Engineering 5416849358 No. 4064 P. 6 \. , -a engineering K & A Engineering, Inc. 91051 S Willamette Street PO Box 8486, Coburg. OR 97408 (541)684-9399 Voice (541) 684-9358 FAX kaengineers.com February 1, 2011 L6'1 \---- 'Of" UJ n tJO/~J Project 11009 , Kast Construction 2860 Martinique Ave Eugene. OR 97408 Subject Foundation Soils 3175 Douglas Drive, Springfield, Oregon Nittany Meadows Subdivision Springfield building permit- 811-SPR2011-00141 PURPOSE AND SCOPE At your request K & A Engineering, Inc. has completed a geotechnical investigation of the exisMg soils on the subject property. Our understanding is that a wood-framed single-family residence is proposed for construction on this site. The purpose of our investigation was to determine the suitability of the soils for construction of the proposed structure, and provide recommendations for construction of the foundation. The scope of our services is limited to general suitability with respect to bearing capacity and expansive soils and did not include testing in-place density of embankments. SITE OBSERVATIONS ExIsUng Sile Condition The lot is located on the south side of Douglas Drive on the west side of South 32" street in Springfield, Oregon. n is Lot 2 in the Nillany Meadows subdivision. The south side of the lot borders a field of the Agnes Stewart Middle School. The lot is on a gentie south facing slope with a gradient of approximately 10-percent Prior to construction, vegetation on the site consisted of moderately dense grass with a few maple trees in the'. south east comer of the iot " We did not observe any slope movement hazards or other indications of overly soft or unstable soils on the subject project site. Subsurface Soil Conditions Based on the foundation pad excavation, soils generally consist of approximately 1 to 2.5-feet of light brown, dense/stiff, moist, organic moderately plastic silt over brown, damp. dense/stiff gravely sandy silt. Visual observations during excavation confirm that the embankment soils are clean (i.e. free from organics or other deleterious materials) and very dense. The foundation excavation. excluding the driveway, was approximately 50-feelx 50-feel in plan. . , , , I. , reb. ~. 1011 9:10AM K&A Engineering 5416849358 No.4064 P) K & A Engineering, Inc. The foundaMn pads were excavated with level benches, with a cut rangJng from approximately 2 to 7 -feet Foundation pad preparation involved constructing a multlple..IJench, level foundation pad on undisturbed native sandy si~ at a depth that would mitigate any geological hazards and was also below the desired footing elevation. We encountered a massive root system In the southeast comer of the foundation pad. The major roots were grubbed out and removed (over Y.-Inch in diameter). After excavation and removal of unsuitable soils, approximately 6-inches to 6.5-leet of 3-inch open graded crushed aggregate was placed, graded. and compacted onto the prepared subgrade. The open-graded liII was placed in approximately G-inch lifts on the subgrade and compacted using a vibratory steel drum roller. An approximately 6-inch lift of 'I.-inch minus. dense-graded crushed aggregate was piaced on the open-graded aggregate. graded and compacted with a steel drum vibratory roller. We observed placement, and tested, the In-place densfly and water content of the crushed aggregate fill. We . have determined 1hat the average dIy density meets or exceeds the 95% of maximum as determined by ASTM 0698. A copy of the test resuns are attached to this report. Note the variability of the compaction results are due to the cleanliness of the imported aggregate materials. RECOMMENDATIONS The foundation pad, as constructed, Is suitable to support conventional cast-in-place concrete spread and strip foo~ngs supporting the proposed light residen~alloads. Foundation loads can bear on the founda~on pad, as prepared, a minimum depth of 12-inches below final grade. The foundation pad. as prepared, will provide an allowable service bearing capacity for conven~onal cast-in- piaced concrete spread footings of 1,500 pounds per square foot The foundation soils at this site have a very low shrinl<lswell potential. Measures to ensure solis moisture con lent stability are not required at this site. Project: 11009 Client Kast Construction Lot 2. 3175 Douglas Drive. Springfield, OR Page 2 of 3 February 1, 2011 ftb, 8, 2011 9~21AM K&A Engi neer ing 5416849358 No. 4064 p,' 8 K & A Elgineering, Ine. UMITATIONS OF THIS REPORT This report has been prepared for the exclusive use of Kast Construction, its design consultants and construction subcontractors for the subject proposed structure. This geotechnical Investigation, analysis, and recommendations meet 1I1e 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, s~e surface, or subsurface conditions. Exploration test holes indicate soil condnions only at specific locations (i.e. the test hole locations) to the depths penetrated. They do not necessaJily reflect soil/rock materials or groundwater conditions that exist between or beyond exploration locations or IImtts. The scope of our services does not Include construction safety precautions, techniques, sequenoes, or prooedures, exoept 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 K you have questions or need further assistance. Respectfully, Chuck Du Faull, r.E. K & A Engineering. Inc. rroject: 11009 Client: Kast Construction Lot 2,3175 Douglas Drive, Springfield, OR Page 3 of 3 February 1. 2011 Fell 8 2011 9:21AM K&A Engineering 5416849358 No.4064 P 9 DenSIty 01 Soil and Soil-Aggregates In-Place ASTM D2922 and D3017 Proiect; 11009 SRe Address: 3175 Doualas Dr., Springfield, Olllnon Perm" No: 811.SPR2011.00141 Dale: 1/27/2011 Densitv Teal Type ': OT iiDaretar: eeo M~lerial Tuna: 3/4' minus dense araded crushed aggreaate Sorinafield Quarry MaDmumDNDeRdw.D~ 141.0 SlandanllZallon and Referenoe Check 11 Density I I~ Moisture'T (Standard DevlatlDns S.D.) 0.32 (S.D:) 1.01 Moist Dry Density, Denslly, Waler Compaction, Test No. pel pel COntent, % % Remarks 1 140.4 132.6 5.9 94.0% 2 146.5 136.7 7.2 97.0% 3 141.2 132.0 7.0 93.6% 4 152.7 142.8 6.9 101.3% Average: 96.5% Std. Ilev.: 3.53% , Direct Transmission (01) (specify depth, in.) or Air Gap Backscatter (AGB) (specifiy(T)ouchable or (U)ntouchable mode Test performed using Seaman Nuclear Corp model e.300, SN 21113 Client Kast ConstruGtion Project: 11009 K & A Engineering, Ino. 2/4/2011