HomeMy WebLinkAboutObservation of Excavation 05.07.2020It A
11rna? & AuY.Jsi::'!; f , Inc. ®
Geotechnical and Materials Engineers
and Environmental Scientists
An Employee Owned Company
5020 County Road 154
Glenwood Springs, CO 81601
phone: (970) 945-7988
fax: (970) 945-8454
email: kaglenwood@kumarusa.com
www.kumatusa.com
Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado
May 7, 2020
Modfin Design + Build, LLP
Attn: Keith Wittenberg
243 Elk Ridge Drive
Glenwood Springs, Colorado 81601
s h a ags 0 9 [;yahoo. c:o m
Project No. 20-7-167
Subject: Observation of Excavation, Proposed Residence, Lot 67, Spring Ridge Reserve,
Hidden Valley Drive, Garfield County, Colorado
Gentlemen:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on May 5, 2020 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 19, 2020, Project No. 20-7-167.
The proposed residence is essentially the same as described in our previous report. Lightly
loaded spread footings placed on the natural soils and sized for an 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 one level from 1/2 to
4 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation
consisted of sandy silt and clay which was typically porous from roots. We understand that the
footing excavation was lowered 10 inches then moistened and compacted to help remedy the
fairly loose soil condition. 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 with the settlement risk mainly if the bearing soils are wetted.
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. It is very important to provide an impervious
membrane below the perimeter foundation drain of the crawlspace and to not provide a perimeter
foundation drain around the slab -on -grade garage to keep drain water from wetting the bearing
soils.
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
Modfin Design+Build, LLP
May 7, 2020
Page 2
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,
Kumar & Associates, Inc.
Steven L. Pawlak,
SLP/kacts.C/7/zol
. E o 15222
Kumar & Associates, Inc.® Project No. 20-7-167
Dave Argo
From: Dave Argo
Sent: Tuesday, May 26, 2020 9:14 AM
To: Matt Provost
Cc: Keith
Subject: FW: Modfin Design Build
Attachments: 20-7-167 (05-07-20) ExcObs signed.pdf
Matt:
I am just getting back into my home office after being out the past 10 days. Don't know if Keith sent this along to you in
my absence or not, but thought I should make sure that you received this copy of Kumar's open hole soils report.
Dave Argo
Plans Examiner
` - Garfield County 1
Community Development Department
108 8th Street, Suite 401
Glenwood Springs, CO 81601
Tel: 970-945-8212 Ext. 1610
Email: dargo@garfield-county.com
Web: garfield-county.com
From: Keith <shaggs09@yahoo.com>
Sent: Monday, May 18, 2020 1:22 PM
To: Dave Argo <dargo@garfield-county.com>
Subject: [External] Modfin Design Build
Please forward this to Matt and let me know he got it. Thank you, Keith
Sent from my iPhone
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