HomeMy WebLinkAboutObservation of Excavation 05.21.2024K+nHffi fi',T#fffin1[ir;"*"
An Employce Ownsd Compony
5020 County Road 154
Glenwood Springs, CO 81601
phone: (970)945-7988
fax: (970) 945-8454
email: kaglenwood@kumarusa.com
www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
May 21,2024
Todd Christman
5970 County Road 109
Carbondale, Colorado 81 623
todd@unionpropertycapital. com
Project No. 23-7-705.A
Subject: Observation of Excavation, Proposed Residence, 5970 County Road 109,
Garfield County, Colorado
Dear Mr. Christman:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on several occasions between April30th and May 21,2024to 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 February 12,2024,
Project No. 23-7-705.
The proposed residence will be a one and two-story wood frame structure with an attached
garage.
At the time of our visits to the site, the foundation excavation had been cut in multiple levels
from2Yz to 4 feet below the adjacent ground surface. The soils exposed in the bottom of the
excavations consisted of relatively dense silty sandy gravel. No free water was encountered
in the excavation and the soils were slightly moist to moist. Onsite sand and gravel soils were
placed as backfill to re-establish foundation grade in the lower, eastern part of the site.
The soils in the garage area consisted of relatively dense, natural silty sandy gravel with cobbles.
The main part of the house was placed on the nafural gtavels with some structural fill placed on
the eastern end of that area. The lower, eastern end of the house was placed on structural fill
over the natural clay soils. The eastern side of the house encountered old fill soils and the patio
area was sub-excavated and structural fill consisting of on-site sandy gravel soils was placed in
8-inch lifts to support this area. The structural fill soils were too rocky to test by nuclear gauge
method but the compaction of the fill appeared satisfactory when observed on May ITth and2l't
in this area.
The soil conditions exposed in the upper part of the excavation were consistent with those
previously encountered on the site. The lower part of the lot was not accessible to our drill rig
at the time of drilling in late January. The clay soils that were encountered in the lower part of
the lot at the time of excavation were not suitable for foundation support and were sub-excavated
and replaced with compacted structural fill suitable for support of spread footings designed for
the recommended allowable bearing pressure of 3,000 psf. Other recommendations presented
in our previous report which are applicable should also be observed.
Todd Christman
May 20,2024
Page2
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 leffer. 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 & Associatest
Daniel E. Hardin,
Rev. by: SLP
cc: Hinge kurt@
Kumar & Associates, lnc. @ Project No.23-7-705.A