HomeMy WebLinkAboutBuilding Correspondence 2002-7-15
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K & A Engineering, Inc.
P.O. Box 23624, Eugene, OR 97402
521 Markel SI., Suile B, Eugene, OR 97402
(541) 684-9399 Voice
(541) 684-9358 FAX
~ngin~~ring
July 15, 2002
Project 62.02
Steve Boffing
746 "0" Street
Springfield. OR 97477
S~ Evaluation of Foundation Soils
1278 Oelrose
Springfield Permit No. 02-00673-01
INTRODUCTION
As requested, K & A Engineering, Inc. has completed a geotechnical investigation of existing foundation soils at
the subject site for a new single.family residence.
The proposed building site is situated on a relatively level lot that is part of a subdivision created in old
agricultural lands on the McKenzie River delta region. The original geotechnical investigation for the
subdivision' made reference to "undocumented fills" in the subdivision. The City of Springfield building official
therefore required that this lot be investigated to determine if it contained loose fills and, if so, make
recommendations for making the site suitable for construction of a single-family residence.
The purpose of this investigation was to determine if loose fill soils were at the are of the proposed foundation
and to make recommendations for suitability of the existing soils for supporting a conventional cast-in.place
concrete spread and strip footing foundation.
INVESTIGATION
Two borings were made on the site. These were made using a 4.inch hand auger to 6-feet below the existing
ground leveL Soil recovered from the boreholes were visually classified and logged.
Borehole AH 1 was located at the southeast corner of the foundation area. Borehole AH2 was located at the
northwest corner of the foundation area. Soils in each borehole were nearly identical in classification, depth,
and consistency. Soils in the boreholes consisted of 3 to 6-inches of 3J.,-inch minus crushed aggregate over
3.5.fee1 ot dense, brown, slightly damp to dry, slightly plastic silt (ML). At a depth of approximately 4-feet the
silt gradually increased in moisture content and fine sand content, having a classification of damp to moist,
dense, slightly plastic sandy,silty (SM).
, Report by PSI, date unknown, a portion of which copy was attached to permit papers for this project.
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K & A Engineering, Inc.
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SUMMARY AND RECOMMENDATIONS
There is no evidence of any loose fills on the site. We could not find a vegetative layer that suggested fills
pushed over existing ground. The soils observed in the boreholes are consistent with local geology, grading
from silty topsoil to more granular soils at depth, and most likely to alluvial gravels at a depth below our borings.
The soils have good drainage characteristics and an allowable bearing capacity exceeding 1,500 pounds per
square foot.
We recommend approval of the site, as prepared, for construction of the proposed cast-in.place, reinforced
concrete foundation.
LIMITATIONS OF THIS REPORT
This report has been prepared for the exclusive use of Steve Boffing and his design consultants for the subject
proposed structure.
This geotechnical investigation, 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 subsurface conditions. Exploration test holes indicate
soil conditions only at specific locations (Le. the test hole locations) to the depths penetrated. They do not
necessarily reflect soiVrock materials or groundwater conditions that exist between or beyond exploration
locations or limits.
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 for the opportunity to be of service. Please call if you have any questions.
Sincerely,
EXPIRES /1-(3, 16'")_
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Michael Remboldt, P.E.
K & A Engineering. Inc.
Client: Steve Bolling
Project: 62.02
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July 15, 2002