HomeMy WebLinkAboutObservation of Excavation 06.20.2018P%KU MAR
Geotechnical Engineering 1 Engineering Geology
Materials Testing 1 Environmental
5020 County Road 154
Glenwood Springs, CO 81601
Phone: (970) 945-7988
Fax: (970) 945-8454
Email: hpkglenwood@kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, Summit County, Colorado
June 20, 2018
CMC Group
Attn: Jim Bickling
200 S. Colorado Blvd, Suite 10500
Denver, Colorado 80222
jimbickling@gmail.com
Subject:
Dear Jim:
Project No. 17-7-174.A
Observation of Excavation, Proposed SRE Building, Garfield County Airport,
County Road 352, Garfield County, Colorado
As requested, a representative of H-P/Kumar observed the excavation at the subject site on June
20, 2018 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 March 6, 2017, Project No. 17-7-174. The current observation was performed
according to our Agreement for Professional Services with CMC Group Dated June 11, 2018.
At the time of our visit to the site, the foundation excavation had been cut in one level from 1 to
3 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of sandy silt and clay in the northern part of the excavation and clayey silty sand and
gravel in the southern part of the excavation. The soils appeared to be well compacted. No free
water was encountered in the excavation and the soils were slightly moist to moist. A few
oversized rocks tgreater than 6 inches) were observed on the surface of the excavation.
The soil conditions exposed in the excavation are consistent with those previously encountered
on the site and suitable for support of continuous spread footings designed for the recommended
allowable bearing pressure of 1,500 psf and column footing pads designed for the recommended
allowable bearing pressure of 2,000 psf. Loose and disturbed soils should be compacted or
removed in the footing areas to expose the undisturbed natural soils. Oversized rock (greater
than 6 inches) should also be removed in footing and floor slab areas. 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
CMC Group
June 20, 2018
Page 2
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. 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 a professional in
this special field of practice should be consulted.
If you have any questions or need further assistance, please call our office.
Sincerely,
H -P; KUMAR
Robert L. Duran, E. I.
Reviewed by:
Steven L. Pawlalk
RLD/kac
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H-PtKUMAR
Project No. 17-7-174.A