HomeMy WebLinkAboutObservation of Excavation 09.09.2022
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
September 9, 2022
Armando Rivas
P.O. Box 964
Glenwood springs, Colorado 81602
armandorivas_19@hotmail.com
Project No. 21-7-142.01
Subject: Observation of Excavation, Proposed Residence, Lot 2, Gobbler’s Knob,
Donegan Road, Garfield County, Colorado
Armando:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on August 29, 2022 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 March 2, 2021, Project No. 21-7-142.
The residence will be above a walkout basement level with the garage at the main level. Spread
footings placed on the natural soils and sized for the recommended allowable bearing pressure of
1,500 psf were designed for the foundation support.
At the time of our visit to the site, the foundation excavation had been cut in multiple levels from
2 to 5 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of mainly silty sandy clay with gravel and gravelly soils in the eastern area. Loose fill
soils covered the southwest part of the basement floor area outside of the footing excavation. No
free water was encountered in the excavation and the soils were slightly moist.
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 1,500 psf. Loose disturbed soils in the footing areas should be moistened and
compacted or removed to expose the undisturbed natural soils. Other recommendations
presented in our previous report which are applicable, including those to compact soils below
floor slab areas to at least 95% of standard Proctor density, should also be observed.
Armando Rivas
September 9, 2022
Page 2
The recommendations submitted in this letter are based on our observation of the soils exposed
within the foundation excavation and the previous 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 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,
Steven L. Pawlak, P.E.
SLP/ljf
cc: Uriel Mellin (uriel.mellin@hotmail.com)
Kumar & Associates, Inc. ® Project No. 21-7-142.01