HomeMy WebLinkAboutObservation of Excavation 11.16.2019K+AKumar & Associates, Me. 0
Geotechnical and Materials Engineers 5020 County Road 154
and Environmental Scientists Glenwood Springs, CO 81601
phone: (970) 945-7988
fax: (970) 945-8454
email: kaglenwood@kumarusa.com
An Employee Owned Company www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
& Assodatos '
November 15, 2019
D.M. Neuman Construction
Attn: Jason Neuman yL42" sOL
P.O. Box 2317 www.kumarusax m
989_Z
Glenwood Springs, Colorado 81602 �Q�9
jmn : dmneuman.com
Project No. 18-7-692.A
Subject: Observation of Excavation, Proposed Garage, 2808 Four Mile Road (County
Road 117), Near Bottom of Bershenyi Dip, Garfield County, Colorado
Dear Jason:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on November 14 and 15, 2019 to evaluate the soils exposed for foundation support.
The findings of our observations and recommendations for the foundation design are presented
in this report. These services were performed as supplemental to our agreement with D.M.
Neuman Construction dated November 13, 2018. We previously conducted a subsoil study for
design of foundations at the site and presented our findings in a report dated January 28, 2019,
Project No. 18-7-692.
The proposed garage will be a one-story, wood frame structure with a slab -on -grade floor.
Foundation loadings are assumed to be relatively light and typical of the proposed type of
construction.
At the time of our November 14 visit to the site, the foundation excavation had been cut in
2 levels from 6 inches to 5 feet below the adjacent ground surface. Fill soils were exposed in the
bottom of the deeper excavation. The fill soils in their existing condition are not suitable for
support of the garage and need to be removed down to the natural soils prior to placement of
structural fill.
At the time of our November 15 visit to the site the excavation was approximately 85% complete
and had been cut in 2 levels from 6 inches to 10 feet below the adjacent ground surface. The
soils exposed in the bottom of the excavation consisted of natural silty sand with gravel. 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. The exposed soils in the building area should be moistened and
D.M. Neuman Construction
November 15, 2019
Page 2
compacted. Structural fill used to reestablish the bearing grade can consist of the on -site material
devoid of vegetation, topsoil and rock greater than 6 inches. The structural fill and bearing soils
should be protected from frost and concrete should not be placed on frozen soils. 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. 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.
James H. Parsons, E.I.
Reviewed by:
Steven L. l
JHP/kac
Kumar & Associates, Inc. " Project No. 18.7-692.A