HomeMy WebLinkAboutPermit Geo-Tech Report 2007-2-23
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K & A Engineering, Inc.
3327 Roanoke Ave., Eugene, OR 97408
(541) 684-9399 Voice
(541) 684-9358 FAX
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engineering
February 23, 2007
Project: 151.06
Hayden Enterprises, Inc,
2464 SW Glacier Drive #110
Redmond, OR 97756
Subject: Jasper Meadows subdivision--Lot207
Springfield, OR
Foundation Soils
PURPOSE AND SCOPE
At your request, K & A Engineering, Inc, has completed a geotechnical investigation of the existing soils on the
subject property. Our understanding is that a wood-framed single-family residence supported by a cast-in-
place concrete spread footing foundation 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,
FOUNDATION PAD PREPARATION
The project site is located on a residential lot on the south side of Cinder St in the new "Jasper Meadows"
subdivision, The lot is level and there are no apparent slope movement hazards, The site is in a traditionally
low-iying area that is being raised to a level even with the surrounding subdivision,
'Based on the foundation pad excavation, soils consist of approximately 12.inches of dark brown, loose, organic
silt, over 12-inches of wet, gray, plastic silt, over saturated, moderately dense, decomposed sandstone.
Foundation preparation involved constructing a'level foundation pad on native undisturbed soils., This required
stripping and removing approximately 24-inches of loose silts and undocumented fill in the foundation pad area,
After the excavation and removal of the unsuitable soils, approximately 48-inches of 8-inch minus crushed
quarry "pit run" was placed and compacted on the foundation pad area, followed by 12-inches of 3;4-inch minus
dense graded crushed aggregate, This served to provide a uniform surface for footing construction. The fill
materials were placed in maximum lifts of 12-inches and compacted using a vibratory steel drum roller. We
inspected the foundation pad excavation, prior to placement of the granular fills,
We inspected the placement of the 8-inch minus crushed quarry "pit-run" and the 3;4-inch minus dense-graded
crushed aggregate. The "pit-run" was too large to test for maximum dry density and optimum water content by
, conventional laboratory testing, therefore, adequate compaction was determined in the field by visual inspection
of the compaction effort The "pit-run" was placed in 12-inch maximum lifts and compacted with a vibratory
steel drum roller,
K & A Engineering, Inc.
We tested the in-place density of the crushed aggregate fill and have determined that the average dry density
exceeds 95% of maximum as determined by ASTM 0698, The field test results are attached to this report
SUMMARY AND RECOMMENDATIONS
The project site, as prepared, is suitable to support the proposed foundations, We recommend a design
allowable bearing capacity of 2,500-pounds per square foot
The soils present a moderate shrink/swell hazard, Foundation loads should bear on undisturbed native silts a
minimum depth of 36-inches beiow final grade around the perimeter foundation, The prepared foundation pad
meets these requirements.
Final grading around the foundation pad should raise the grade above the foundation using native or imported
silts and should slope away from the foundation.
We recommend approval of the foundation pad, as constructed, by the building ollicial,
Thank you for the opportunity to be of service, Please call us if you have questions or need further assistance,
Respectfully,
~
Steve Schultz, En,
K & A Engineering, Inc,
EXPIRES -.nEt.' 3 0 20D8 .
. Revised on 11/19/07 due to the platted lot numbers being different than the design lot numbers,
Client: Hayden Enterprises Jasper Meadows-Lot 207, Springfield, OR
Project: 151.06
Page 2 of 2
February 23, 2007
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Density of Soil and Soil-Aggregates In-Place
ASTM 02922 and 03017
Project: 151.06
Site Address: Jasper Meadows--Lot 207
Permil No:
Date: 2/14/2007
Density Test Type': OT-6
Operator: SS
Material Type: 3/4" (-) from Springfield Quarry
I Maximum Dry Denstiy, pcf 128,0
I Standardization and Reference Check f!" Density
(Standard Deviations) (S,D,) 0,23
If!" Moisture, I
(S.D:)
Moist' Dry
Density, Density, Waler Compaction,
Test No. pel pel Conlent, % % Remarks
1 145,1 135,1 7.4 105.5%
2 138.3 129,3 6,9 101.0%
3 139,3 132.0 5,5 103,1%
Average, 103,2%
Std. Oev,: 2,27%
1.66
. ' Direct Transmission (OT) (specify depth, in,). or Air Gap Backscatter (AGB) (specifiY(T)ouchableor (U)ntouchable
mode
Test performed using Seaman Nuclear Corp model C-300, SN 21113
Client: Hayden Enterprises, Inc,
Project: 151,06
K & A Engineering, Inc.
11/19/2007