HomeMy WebLinkAboutObservation of Excavation 05.03.24lGn flff*fl'mfmiHfd-*
email:
An En$oygc Otf,ncd ComPonY
5020 County Road 154
Glenwood Springs, CO 81601
phone: (970) 945-7988
fax; (970) 945{454
kag lenwood@kumarusa.com
wuryv.kumarusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs' and Summit County, Colorado
May 3,2024
Revised May 15,2024
Walt Posluszny
412 Sun King Drive
Glenwood Springs, Colorado 81601
wa1 tnoslusmv@comcast.net
Subject:
Project No.24-7-286
observation of Excavation, Proposed Shop,412 Sun King Drive, Lot 2, Oak
Meadows Subdivision, 2nd Filing, Glenwood Springs, Colorado
Dear Walt:
As requested, the undersigned representative of Kumar & Associates observed the excavation
at the subject site on May 2,2024 to evaluate the soils exposed for foundation support. The
findings of our observations and recommendations for the foundation support are presented in
this report. The services were performed in accordance with our agreement for professional
engineering services to you dated April 30,2024.
The proposed shop building will be a one-story building with a slab-on-grade floor. The
concrete building walls will be supported on footings designed for an allowable soil bearing
pressure of2,500 psf.
At the time of our visit to the site, the east foundation wall excavation had been cut in three
levels about2Yzto 6 feet below the adjacent ground surface. The soils exposed in the bottom
of the excavation consisted of medium dense, clayey sand and gravel with small rock fragments
No free water was observed in the partial excavation and the soils were moist.
Considering the conditions exposed in the excavation and the nature of the proposed
construction, the proposed footings, placed on the undisturbed natural soil and designed for
an allowable soil bearing pressure of 2,500 psf can be used for support of the proposed shop'
Loose and disturbed soils in footing areas should be removed and the bearing level extended
down to the undisturbed natural soils. Minimum frost depth for footings in this area is 3 feet.
Foundation walls should be reinforced top and bottom to span local anomalies such as by
assuming an unsupported length of at least 10 feet. Foundation walls acting as retaining
structures should also be designed to resist alateral earth pressure based on an equivalent fluid
unit weight of at least 50 pcf for on-site soil as backfill. A perimeter foundation drain should
not be needed for the at-gradeinterior slab elevation. Sffuctural fill placed below floor slab
areas can consist of the on-site soils compacted to at least 95% of standard Proctor density at a
moisture content near optimum. We assume there will be at least 4 inches of 3/o-inch road base
placed directly below the proposed slab-on-grade shop floor. Backfill placed around the
Walt Posluszny
May 3,2024
Revised May 15,2024
Page2
structure should be compacted and the surface graded to prevent ponding within at least 10 feet
of the building.
The recommendations submitted in this letter are based on our observation of the soils exposed
within the foundation excavation and do not include subsurface exploration to evaluate the
subsurface conditions within the loaded depth of foundation influence. This study is based on
the assumption that soils beneath the footings have equal or better support than those exposed.
The risk of foundation movement may be greater than indicated in this report because of possible
variations in the subsurface conditions. In order to reveal the nature and extent of variations in
the subsurface conditions below the excavation, drilling would be required. It is possible the
data obtained by subsurface exploration could change the 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 & Assoclates,
Daniel E. Hardin, P
DEH/kac
Kumar & Associates, lnc. o Project No.24-7-286