HomeMy WebLinkAboutObservation of Excavation 05.09.16~tee
HEPWORTH· PAWLAK GEOTECHNICAL
May9, 2016
Tom Jurmu
1902 County Road 214
Silt, Colorado 8 I 652
tomjurrnu@gmail.com
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Job No. 114 505A
Subject: Observation of Excavation, Proposed Residence, Lot 3, Dutch Major
Exemption, 997 County Road 229, Garfield County, Colorado
Dear Mr. Junnu:
As requested, a representative of Hepworth-Pawlak Geotechnical, Inc. observed the
excavation at the subject site on May 2, 2016 to evaluate the soils exposed for foundation
support. The findings of our observations and recommendations for the foundation
design are presented in this report. We previously conducted a subsoil study for design of
foundations at the site and presented our findings in a report dated November 26, 2014,
Job No. 114 505A.
We understand that the proposed walkout basement was eliminated and the lower level
will be slab-on-grade.
At the time of our visit lo the site, the foundation excavntion had been cut in one level
from I Vl to 3 feet below the adjacent ground surface. The soils exposed in the bottom of
the excavation consisted of medium stiff to stiff, sandy silt and clay. The exposed footing
subgrade had been compacted. Results of swell-consolidation testing performed on a
sample taken from the site, shown on Figure I, indicate the soils have low to moderate
compressibility under conditions of loading and wetting with a minor collapse potential
(settlement under constant load) when wetted. No free water was encountered in the
excavation and the soils were slightly moist to moist.
The soil conditions exposed in the excavation are consistent with those previously
encountered on the site and suitable for support of spread footings designed for the
recommended allowable bearing pressure of 1,500 psf. An underdrain system should not
be needed for the proposed slab-on-grade lower floor level and we recommend that it not
be installed. Site grading around the house should drain away on all sides as described in
the S111face Grading section of our previous report. Other recommendations presented in
our previous report which are applicable should also be observed.
The recommendations submitted in this letter are based on our observation of the soils
exposed within the foundation excavation and the previous subsurface exploration at the
site. Variations in the subsurface conditions below the excavation could increase the risk
of foundation movement. We should be advised of any variations encountered in the
excavation conditions for possible changes to recommendations contained in this letter.
Parker 303-841-7119 • ColorndoSprings 719-633-5562 • Sihenhornc 970468-1989
Tom Jurmu
May9, 2016
Page2
Our services do not include determining the presence, prevention or possibility of mold or
other biological contaminants (MOBC) developing in the future . If the client is
concerned about MOBC, then u professional in this special field of practice should be
consulced .
If you have any questions or need further assistance, please call our office.
Sincerely,
HEPWORTH -PAWLAK GEOTECHNICAL , lNC.
Rev. by: SLP
DEH/ksw
attachment Figure 1 -Swell·Consolidation Test Results
cc: Albright & Associates -Jack Albright iiack@albri ghHt >~ociatcs.com
Job No . 114 SOSA
Moisture Content ,., 12.1 percent
Dry Density = 106 pcl
Sample of: Sandy Silt and Clay
From: Foot .ng Grade Near Southeast Corner of
House
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1
~ .. ~ ~ -;...---" -,, • Compression j~ t _1-:.."-upon
~ 2 weltlng
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0 I 1.0 10 100
APPLIED PRESSURE • ksl
114 505A ~ SWELL-CONSOLIDATION TEST RESULTS Figure 1
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