HomeMy WebLinkAboutAdditional Observation of Excavation 07.05.2022lGrtiffi,ffir'#'i*"
An Emdoyåa Oû,vncd Compony
5020 County Road 154
Glenwood Springs, CO 81601
phone: (970) S45-7988
fax; (970) 945-8454
email: kaglenwood@kumarusa.crm
www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Surnmit County, Colorado
July 5,2022
Eric Conklin
1800 Black Diamond Mine Road
Glenwood Springs, Colorado 8ló01
conklinweldinq(r¿gmail'corn
proJect No. 2r-7-751
Subject: Additional Observation of Excavation, Proposed ADU, 1800 Black Diamond
Mine Road, Garfield County, Colorado
Gentlernen:
As requested by Rick Penin, a representative of Kumar & Associates, Inc. observed the
excavation at the subject site on June 30, 2022 to evaluate the soils exposed for foundation
supporl. The findings of our observations and recommendations for the foundation design are
presented in this report. Úe previously evaluated the soils at the original ADU location for
design of foundations and presented our findings in a report dated September 27 ,2021, Project
No. 2l -7-751. The current observation was conducted supplemental to our professíonal services
agreement with Eric Conklin dated September 14,2021.
The current ADU building site is located immediately west of the original site and will be of
similar design and construction. Spread footings placed on the natural soils and sized for an
allowable bearing pressurçcf 2,000 psf were designed for the foundation support.
At the time of our visit to füç"site, the foundation excavation had been cut in one level from 1 to
9 feet below the adjacent grouird,surface. The soils exposed in the bottom of the excavation
consisted of stiff sandy.clay with scattered gravel and occasional cobbles. No free water was
encountered in the excavation and the soils were moist. Spread footings and foundation walls
had been constructed.
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 disturbed soils should be removed in the footing areas to
expose the undisturbed natural soils (if any). Other recommendations presented in our previous
report which are applicable should also be observed.
The recomrnendations submitted in this letter are based on our observation of the soils exposed
within the foundation excavation and the previous limited subsoil evaluation 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 rnold or other biological
Eric Conklin
July 5,2022
Page2
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 &, Inc.
Louis E. Eller
Reviewed by:
Steven L. Pawlak,
LEE/kac
cc: Rick Perrin
Kumar & Aseociales, lnc. @ Project No. 21-7-751