Soils ReportBRAUN
I NTE RTEC
The Science You Build On.
May 14, 2015
Mr. Tom Gonyea
Estate Development Corporation
15250 Wayzata Boulevard, Suite 101
Wayzata, MN 55391
Re: Test Pit Observations
Lake Lucy Road Site
Lake Lucy Road and Yosemite Avenue
Chanhassen, Minnesota
Dear Mr. Gonyea:
Braun Intertec Corporation Phone: 952.995.2000
11001 Hampshire Avenue S Fax: 952.995.2020
Minneapolis, MN 55438 Web: braunintertec,com
Project B1503769
We recently completed test pit observations for a proposed 4 -lot single-family residential
development in Chanhassen, Minnesota. The purpose of the test pit observations was to assist you
and your design team in evaluating the subsurface soil conditions with regard to designing and
constructing the new development.
Site Conditions
This site is mostly wooded with some open space in the boulevard area along Lake Lucy Road. The
boulevard area is also about 4 to 8 feet higher than Lake Lucy Road with a high point elevation of
about 1040. The northwest side of the property slopes down into a wetland at an elevation of about
1000. An existing house is also present on this site.
Test Pit Observations
A total of 4 shallow test pits were excavated on May 6, 2015 on the lower side of the slope on this
property. The test pits were taken on the north side of the existing slope on this property. The soils
observed in the test pits generally consisted of about 1 to 11/2 feet of organic clay topsoil followed
by lean clay or sandy lean clay to the termination depths of the test pits of around 3 feet. The test
pits were terminated at shallow depths to avoid disturbing the roots of the trees on this property. At
this depth, the soils observed also consisted of glacially deposited soils that were judged to be stiff.
We also noted several small mounds of soil on the lower part of the north -facing slope that appeared
to be fill soils. The backhoe dug into these shallow mounds and it was determined that these mounds
were fill soils.
AA/r.0r.
Estate Development Corporation
Project B1503769
May 14, 2015
Page 2
Recommendations
Based on the results of our test pit observations, we recommend removing the fill soils and topsoil
from beneath the proposed future houses and then placing engineered fill as needed to construct
the house pads. The excavations to remove poor soil should also be extended laterally at least 1 foot
for each foot of fill required below the proposed house pads (1:1 oversizing). A geotechnical engineer
should evaluate the suitability of the soils in the bottoms of these excavations prior to placing
compacted fill.
As the fill soils are placed on the future house pads, we recommend benching into the natural sloped
soils to key the fill soils into the existing slopes. The benches should be at least 8 feet wide and be
constructed about every 4 to 5 feet vertically.
The fill soils should be placed in thin lifts with each lift compacted to a minimum of 98 percent of the
standard Proctor dry density (ASTM D 698). If clayey soils are used to construct the house pads, the
moisture content of the fill soils should be no less than 1 percentage point below and no more than 3
percentage points above the soils optimum moisture content.
If the compacted fill soils on individual lots exceed 10 feet, we also recommend a construction delay
between site grading and house construction of 3 to 6 months be implemented so that the clay fill
can consolidate under its own weight. If a construction delay is not possible, some of the house pads
can be constructed with imported sand fill and limiting the thickness of clay fill to 10 feet or less.
If the house pads are constructed as recommended, it is our opinion that the natural clayey soils as
well as the compacted fill soils should be suitable to support the proposed houses using typical
spread footing foundations sized for a maximum net allowable soil bearing pressure of up to 2,000
pounds per square foot (psf).
Construction Observations and Testing
As the house pads are being prepared, we recommend that a geotechnical engineer be present to
observe the suitability of the soils to support the additional fill and house loads. Compaction testing
should also be completed on the fill soils used to construct the house pads.
BRAUN
INTERTEC
Estate Development Corporation
Project B1503769
May 14, 2015
Page 3
Remarks
In performing its services, Braun Intertec used that degree of care and skill ordinarily exercised under
similar circumstances by reputable members of its profession currently practicing in the same
locality. No warranty, express or implied, is made.
If you have any questions about this report, please contact Henry Vloo at 952.995.2238 or
hvloo@braLrnintertec.com.
Sincerely,
BRAUN INTERTEC CORPORATION
Professional Certification:
I hereby certify that this plan, specification or report
was prepared by me or under my direct supervision
and that I am a duly Licensed Professional Engineer
under the laws of the State of Minnesota.
Henry Vloo, PE
Associate Principal — Senior Engineer HENRY VLOO, PE
License Number: 21140 '., 21140
May 13, 2015 , o`a ••
I
Ray A. Huber, PE
Vice President —Principal Engineer
Attachments:
Sketch of Test Pit Locations
c: Mr. Mark Rausch; Alliant Engineering
BRAUN
INTERTEC