HomeMy WebLinkAboutObservation of Excavation 04.27.2020ICLA
Kumar & Associates, Inc.
Geotechnical and Materials Engineers
and Environmental Scientists
An Employee Owned Company
5020 County Road 154
Glenwood Springs, CO 81601
phone;: (970) 945-7988
fax: (970) 945-8454
email: kaglcnwood(a)kumarusa.com
• www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Port Collins, Glenwood Springs, and Summit County, Colorado
April 27, 2020
Juan Cardenas
27653 Highway 6, #609
Rifle, Colorado 81650
ltarreo1a29Qginail.com
Project No. 19-7-258
Subject: Observation of Excavation, Lot 29, Sun Meadow Estates, South Meadow Circle,
South of Antonelli Lane, Garfield County, Colorado
Dear Juan:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on April 22, 2020 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 May 17, 2019, Project No. 19-7-258.
The proposed construction consists of a one story wood frame structure with attached garage.
Ground floor will be slab -on -grade. Spread footings sized for an allowable bearing pressure of
2,000 psf were designed for support of the residence.
At the time of our visit to the site, the foundation excavation had been cut in multiple levels from
1 to 6 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of silty sandy clay in the shallower excavation and silty sand in the deeper excavations.
Results of swell -consolidation testing performed on samples taken from the site, shown on
Figure 1, indicate the soils are slightly compressible under light loading and had a low collapse
potential when wetted under a constant load. The sample was moderately to highly compressible
under increased loading after wetting. 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 2,000 psf. Loose and disturbed soils should be removed in the footing areas
to expose the undisturbed natural soils. Other recommendations including the "Surface
Drainage" recommendations presented in our previous report which are applicable should also
be observed.
Juan Cardenas
April 27, 2020
Page 2
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. 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,
Kumar & Associates, Inc.
9w"'ziv
James H. Parsons, E.I.
Reviewed by:
Daniel E. Hard'
JHP/kac
attachments Fi
cc: Luis Arreola
olidation Test Results
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ADDITIONAL COMPRESSION
UNDER CONSTANT PRESSURE
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L0 APPLIED PRESSURE — KSF 10 100
19-7-258
Kumar & Associates
SWELL—CONSOLIDATION TEST RESULT
Fig. 1