HomeMy WebLinkAboutObservation of Excavation 09.13.2023Kumar & Aaaactato% tnc.®
'( 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 Employes OWMd Company www.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
September 13, 2023
Woodstone, Inc.
Attn: Alan Short
263 Lewis Lane
Basalt, Colorado 81621
alan(a)woodstoneinc. com
Project No. 23-7-104
Subject: Observation of Excavation, Proposed Rec Room Addition, Nickolay Residence,
5011 County Road 154, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the partial excavation at the
subject site on September 13, 2023 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 February 13, 2023, Project No. 23-7-104.
The rec room addition is off of the southeast corner of the residence and gridlines E-H and 2-4.
Spread footings placed on the natural soils below existing fill and sized for an allowable bearing
pressure of 1,500 psf with a risk of differential settlement were designed for the foundation
support.
At the time of our visit to the site, the foundation excavation had been cut in three levels from
about 6 to 15 feet below the adjacent ground surface and down to the bearing level of the
existing building foundation. The soils exposed in the bottom of the excavation consisted of red,
very silty clayey sand with scattered gravel and cobbles. No free water was encountered in the
excavation and the soils were slightly moist. The southeast corner of the rec room area was still
being excavated.
The soil conditions exposed in the excavation are consistent with those previously encountered
on the site and can be used for support of spread footings designed for an allowable bearing
pressure of 1,500 psf with a risk of differential settlement and building distress. The exposed
soils in footing areas should be moistened and well 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
Woodstone, Inc.
September 13, 2023
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,
KI
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Kumar & Associates, Inc. ® Project No. 23-7-104