HomeMy WebLinkAboutB17-0422 soils report.pdf H-P KU mAR5020 County Road 154
ti Glenwood Springs, CO 81601
Geotechnical Engineering I Engineering Geology Phone: (970)945-7988
Materials Testing I Environmental Fax: (970)945-8454
Email: hpkglenwood@kumarusa.com
Office Locations: Denver(HQ), Parker, Colorado Springs, Fort Collins,Glenwood Springs, Summit County, Colorado
February 19, 2018
Ryan Surroz
2495 South Clayton Street
Denver, Colorado 80210
mrsurroz@outlook.com
Project No. 17-7-409.A
Subject: Observation of Excavation, Proposed Eastern Duplex Unit Residence, Lot 16,
Block 9, Bighorn Third Addition, 4273 Columbine Drive, Vail, Colorado
Dear Ryan:
As requested by Jared Kedrowski, a representative of H-P/Kumar observed the excavation at the
subject site on February 7,2018 to evaluate the soils exposed for foundation support. The
findings of our observations and recommendations are presented in this report. The services are
supplemental to our agreement for geotechnical engineering services to you dated August 3,
2017.
We previously conducted a subsoil study for design of foundations at the site and presented our
findings in a report dated September 12, 2017, Job No. 17-7-409. We also observed the
foundation excavation for the western duplex unit as reported in our letter dated December 7,
2017, Project No. 17-7-409. A. The proposed construction is similar to that discussed in our
previous reports. Our subsoil study report recommended spread footings for foundation support
designed using an allowable soil bearing pressure of 2,500 psf.
At the time of our February 7 site visit, the foundation excavation for the eastern unit was
essentially complete and had been cut in generally two levels from about 3 to 10 feet below the
adjacent ground surface. The soils exposed in the bottom of the excavation consisted of
relatively dense, slightly silty sandy gravel and cobbles with boulders to several feet in diameter.
No free water was encountered in the excavation and the soils were slightly moist to moist. The
footings were in place and the foundation walls being formed.
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 2,500 psf. Loose and disturbed soils should be removed in the footing areas
Ryan Surroz
February 19, 2018
Page 2
to expose the undisturbed natural coarse granular soils and the subgrade compacted. Voids
resulting from large cobble and/or boulder removal below footing areas should be backfilled
with sand and gravel soils compacted to at least 98% standard Proctor density. The bearing soils
should be protected from frost and concrete should not be placed on frozen soils. Other
recommendations presented in our previous report which are applicable 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.
If you have any questions or need further assistance, please call our office.
Sincerely,
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cc: Kedrowski Builders—Jared Kedrowski (jaredkedro@aol.com)
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Prniart Mr 17-7-Ana A