HomeMy WebLinkAboutEngineer's Letter 10.29.2014Canyon Engineering, Inc,
October 29, 2014
Jarrid Hadland
D.M. Neuman Construction
310 19th Street
Glenwood Springs, CO 81601
RE: Holmes Garage — South Wall Soil
Jarrid:
During HP Geotech's field visit they found the soil on the south wall of the Holme's Garage
project to have a softer clay soil than anticipated. The initial recommendation was to
lower the foundation until a more solid granular soil was reached for the 2,500psf of
allowable bearing pressure described in their original soils report. After excavating
another approximately 10", it was discovered that the ground water was becoming an
issue. At that point HP Geotech advised you to stop digging and requested that we review
the design and determine if a 1,500psf allowable bearing pressure would be acceptable
along the south wall of the structure. After reviewing the loads, the reduced bearing
pressure was determined to be adequate. In the event the floor load for the ADU is added
to this wall in the future, this loading combined with the dead weight of the wall and footer
will be approximately 900 psf.
Though it was not prescribed by HP Geotech, we discussed increasing the footer from an
18" to 24" footing along the east wall from the SE corner to the point where the footer
steps up to the standard 97'-4 top of footer elevation. This too is acceptable and will
decrease the pressure applied to the soil in the event we have softer soil at this corner.
Thank you for requesting our review of this matter. Please give me a call if you or the
building official has any questions.
Sincerely,
- a k
Jeff Peterson, P.E.
CANYON ENGINEERING, INC.
P.O. Box 398 • Glenwood Springs, CO 81602 • (970) 945-5138 • FAX (970) 945-5138