HomeMy WebLinkAboutObservation of Excavation 06.29.2022K+AKmw & Associates, Inc.*
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.kumarasa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
June 29, 2022
Burkholder Construction
Attn: Todd Burkholder
P.O. Box 400
Carbondale, Colorado 81623
todd(u),burkholderhomesinc.com
Project No. 21-7-665.A
Subject: Observation of Excavation, Proposed Residence, Lot 77, Pinyon Mesa,
374 Pinyon Mesa Drive, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site between June 7 and 21, 2022 for bearing soil conditions and compaction testing of
backfill below footing areas. 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 11, 2021,
Project No. 21-7-665. The observations and testing were performed in accordance with our
agreement for professional services with Burkholder Construction dated June 6, 2022.
The proposed residence is essentially the same as described in our previous report and is
designed for spread footings placed on 3 feet of compacted onsite soils and sized for the
recommended bearing pressure of 1,500 psf.
At the time of our visits, the foundation excavation was cut in multiple levels stepped down to
the southwest with the natural ground surface. The soils exposed in the bottom of the excavation
consisted of slightly moist, sandy clay and clayey silt. Results of in-place density testing
performed on the soil backfill below footing areas (presented separately) indicate compaction to
the minimum 98% of standard Proctor density.
The soil conditions exposed in the excavation and compacted backfill are consistent with those
recommended for foundation support and spread footing sized for an allowable bearing pressure
of 1,500 psf. Loose disturbed soils in the footing areas should be moistened and compacted.
Other recommendations presented in our previous report which are applicable, especially those
to keep the bearing soils dry, 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 limited 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
Burkholder Construction
June 29, 2022
Page 2
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.
Steven L. Pawl,
SLP/kac
Kumar & Associates, Inc. " Project No. 21-7-665.A