HomeMy WebLinkAboutObservation of Excavation 06.17.16I • ~tech
HEPWORTH· PAWLAK GEOTECHNICAL
June 17. 2016
Aspen Built Homes, Inc .
Attn: Abdi Pirzadeh
P.O. Box 3551
Basalt, Colorado 81621
asnc.nb uilt homes @_g mail.com
llq•\11•r!h•l .1\\'l,1k GL·nfL0d1111c..1l. In_
5(.120 CtllllH\ Rt• td I 'i-l
GIL n1n ~ ,J Spnni.:;, Col11r:11l11 HI «iO I
Ph1 inc 9 iO ~l4; • 7tJtiS
F 1x tJiu-9-15-S-!'>~
cm 111 hri..l11&11p::Lo[lCh ._.1111
Job No. 116 030A
Subject: Observation of Excavation, Proposed Residence. Lot 3. Four Mile Ranch,
Red Cliff Circle, Garfield County, Colorado
Dear Mr. Pirzadeh:
As requested, a representative of Hepwonh-Pawlak Geotechnical, Inc. observed the
excavation nt the subject site on June 14, 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 October
31. 2016, Job No. 105 772.
The proposed residence will be one and two story wood frame structure above a basement
and with an attached garage. Basement and gar.1ge floors will be slab-on-grade .
At the time of our visit to the site, the foundation excavation had been cut in two levels
The basement was cut from 3~ to 6~ feet below the adjacent ground surface and the
garage area was cut 2Vz to 3 feet below grade. The soils exposed in the bottom of the
excavation consisted of sandy silty clay. Results of swell-consolidation testing performed
on a sample taken from the site, shown on Figure 1, indicate the soils are slightly
compressible under conditions of loading and wetting. No free water was encountered in
the excavation and the soils were slightly moist to moist.
The soil conditions exposed in the excavation arc 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. Loose and disturbed soils should
be removed in the footing areas to expose the undisturbed natural soils. The excavation
bases should be moistened and compacted prior to placing concrete. 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
Parker 303-841·7119 • Color.ido Springs 719 -633-5562 • Silverthorne 970-468-1989
concerned about MOBC, then a professional in this special field of practice should be
consulted.
If you have any questions or need further assistance, please caU our office.
Sincerely,
HEPWORTH -PAWLAK GEOTECHNICAL, INC.
Reviewed by:
attachments Figure J -Swell-Consolidation Test Results
Job No 116 OJOA
~·
Moisture Content = 13 7 percent
Ory Density -113 pcl
Sample of: Sandy Srlty Clay
From: Bottom of Excavation near Northwest
Corner
~ 0
c: .Q \ ~ ~tl ti)
U) 1 Q) ~ ....... a
§ ~~ (..) 2 No movement
upon
wetting
0.1 1.0 10 100
APPLIED PRESSURE -ksf
116 030A ~
Ht11worth-Pciwlok GeolechnlCCll
SWELL-CONSOLIDATION TEST RESULTS Figure 1