HomeMy WebLinkAboutBuilding Correspondence 2013-6-11 (Branch
ENGINEERING=
Since 1977
June 11, 2013 civil • transportation
structural geotechnical
Mr. Derrick Westover SURVEYING
Bruce Wiechert Custom Homes, Inc.
3073 Skyview Lane
Eugene, Oregon 97405 ,1 99
RE: BUILDING PAD SIBGRADE EVALUATION ��i- ~G�l -000)-itt
584 MTN GATE DRIVE
LOT 54 MOUNTAIN GATE WEST SUBDIVISION(PHASE IV)
SPRINGFIELD, OREGON
BRANCH ENGINEERING INC PROJECT NO. 13-017
A geotechnical engineer visited the above referenced site on June 5, 2013 to observe the building
pad excavation and assess the shrink/swell potential of the subgrade soil, and determine the bearing
capacity of the final building pad grade for construction of a single-family residence. The flat, fill
pad has been scraped of vegetation exposing a hard miscellaneous stone fill subgrade. The pad was
leveled by covering the subgrade with 4- to 6-inches of 3/4"-0 crushed aggregate. Testing of the
subgrade soil indicated a low shrink/swell potential (IS 2720 result of<5%).
The April 5, 2004 by Boire Associates Inc. indicates that Lot 54 is a fill lot as confirmed by our
observations. Slope stability of the lot is good and no other geologic/geotechnical factors will
impede site development as planned. The subgrade is suitable for a conventional perimeter-style
foundation, and an allowable soil bearing capacity of 2,000 psf. We recommend Drat the foundation
perimeter he backfilled and graded to slope away from the structure as soon as concrete curing
allows. Differential settlements are expected to be less than 1/4-inch over a span of 20 feet. Fooling
drains are not required as the subject and adjacent lots area relatively flat. Surface drainage shall be
conveyed to a suitable disposal area, and final perimeter landscape grades shall slope away from the
foundation and surface water not be allowed to pond adjacent to the foundation.
Sincerely,
Branch Engineering Inc,
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Ronald J. Derrick, P.E., G.E. Expires 12/31/2013
Principal Geotechnical Engineer
EUGENE-SPRINGFIELD SALEM-KEIZER
310 5ih Street, Springfield, OR 97477 I p: 541.746.0637 I www.branchengineering.com