HomeMy WebLinkAboutRe: soil/evaluation �
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ITCO ALLIED ENGINEERING CO.
AN ALLIANCE OF INSTANT TESTING COMPANY AND ALLIED TEST DRILLING
Jobsite and Laboratory Testing, Geotechnica/ Services, Commercial, Residentia/and Municipal
7125 West 126th Street, Suite #500 - Savage, MN 55378
Telephone: (952)890-7366 Fax: (952)890-5883
May 8, 2013
Dean Johnson Homes Phone: 763-242-7301
4700 County Road #19
Medina, Minnesota 55357
RE: 1579 Maple Place
Orono, Hennepin County, Minnesota
As requested, a site visit was made on May 6, 2013 at 2:28 P.M. to evaluate and test soils for the
construction of a full basement single-family residence. The proposed build area is located in a 3-lot
tract. A subsurface geotechnical investigation #11036 conducted by Ailied Test Driliing Company
indicates possible unsuitable soils within the site, with a site inspection conducted 6/29/12 within the
adjacent lot, confirmed the requirement for soil corrections within this section of the site.
At the time of the inspection, except for the garage area, the house foundation had been excavated
to approx. footing elevation. The contractor had completed an exploratory test excavation within
the northeast corner of the foundation excavation. At approximately 15 by 9 feet and 3 to 4 feet in
depth, the excavation indicated fully saturated soils and buried undocumented fill, consisting of old
tree debris and some concrete. Perched water rapidly filled the excavation to a depth of
approximately 2 feet. A 1 5/8`h inch diameter fluted hand auger probe put down approximately 3
feet through the water, and into the subgrade soils, indicated a dark horizon "B" zone, underlain by
a competent fine granular material at a depth of approximately 5 to 6 feet, capable of supporting full
body weight applied to the probe. Observations indicate similar soil conditions and fill depths as
those encountered within the neighboring lot tested June 29, 2012. Because of groundwater
infiltration, soil load bearing tests were not conducted, however we would anticipate values
approaching 2000 PSF as documented within the referenced adjacent lot.
Based upon the observed soil conditions, the house pad should be excavated to remove all
undocumented fill and associated debris. We would recommend some level of de-watering as the
unsuitable materials are removed to the zone of dark granular horizon "B" soils, anticipated at a
depth of 5 to 6 feet. Adjustments to proposed build elevation will be accompfished by a dropped
footing design, and/or the placement of a coarse granular fill to above groundwater elevation. If the
upper zone of fill consists of pit run material, we recommend the installation of a geotextile fabric as
a separating or stabilization layer to minimize particle migration.
RECEIVED
I�iAY 1 0 2013
CITY OF ORONO
M
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In our opinion, with the noted corrections or recommendations, the observed and tested sub-grade
soils are acceptable, and would be expected to meet an assumed minimum bearing capacity
requirement of 2000 PSF, for the proposed construction. Our observations and subsequent soil
evaluation on this date is limited in scope to soil conditions observed within the completed
excavations, and to the depths achieved by a shallow probe.
Sincerely,
Itco Allied Engineering Company Reviewed By:
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Gordon J. Kopacek, Professional Engineer—Registration No. 7254
Gary Standish
Senior Inspector
CC: City of Orono Building Inspections
701 - 0 / #605— 1 1/2 /#610—'/4 / #612—53