HomeMy WebLinkAbout20 Baker Lane (18)2
DR. CLARENCE WELTI, P.E., P.C.
GEOTECHNICAL ENGINEERING
227 Williams Street - P.O. Box 397
Glastonbury, CT 06033
860)633-4623/FAX(860)657-2514
February 18, 2000
Mr. George Folwer
Levin/Brown Associates, Inc.
15 Greenspring Valley Road
Owings Mills, MD 21117 Fax 1-410-5 81-0108
Re: Foundation Bearing Pressures at Temple Beth Hillel; South Windsor, CT. Site Visit of
18 Feb 2000 to Inspect Footing Sub-grades
Dear Mr. Fowler:
Yesterday I was informed by your structural engineer that there was a question as regards the
appropriateness of the design bearing pressure at the subject site. This was apparently based on the
optimum density being less than 120 pcf. I visited the site today to inspect the prepared sub-grade
for placement of footings at 3,000 psf presumptive design bearing pressure. The soils were exactly
those described in the test borings on which the bearing pressure was based.
Apart from the fact that the footing pressures have been previously assessed with the boring data and
a rational evaluation of the possible settlements with this data;the building code itself permits the
above loading(3000 psf) a priori. The soil at the footing level is a Fine Sand on which most of the
buildings in the industrial area of South Windsor have footings with presumptive bearing pressures
of 4,000+psf. Most of the sands in the area have optimum densities below 120 pcf and many have
optimum densities below 110 pcf. This does not disallow placement of footings with a loading
typically of 4,000 to 5,000 psf. With blow counts of at least 12/foot(in footing influence zone) and
in most cases of 20+/foot the ultimate capacity of soil at the proposed footing levels would exceed
8 Tons/sf. Using stiffness moduli of at least 300 Tons/sf(based on numerous pressuremeter results
done on similar soils in the Connecticut River valley) the settlements with 3,000 psf will be well
within the settlement criteria in the geotechnical study of 13 Sept1999.
In summary the compacted sub-grade is more than adequate to receive the footings with the
allowable loading of 3,000 psf.The value has been established by rational analyses typically applied
for such assessments.
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If you have any questions, please call me.
Very trul urs. 40:c
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Clarence Welti, PhD, P. E.
r`r:Y,ftPres. Dr. Clarence Welti, P. E., P.C. 0;
cc Mr. John Collins, Building Inspector; Town of South Windsor F, -•,,,.• c
NCTICE OF
cc Dr. Karim Adib, P.E. @ Materials Testing, Inc. Fax 1-203-878-1504
cc Wes Laramee @ Podogil Builders Fax 291-9306
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