HomeMy WebLinkAboutB16-0209_HP Geotech - Soils Report - 9-16-16_1512688149.pdf H-P ICU MAR 5020 County Road 154
1- Glenwood Springs,CO 81601
Geotechnical Engineering l Engineering Geology Phone: (970)945-7988
Materials Testing ti Environmental Fax: (970)945-8454
Email: hpkglenwood@kumarusa.com
Office Locations: Parker,Glenwood Springs, and Silverthorne, Colorado
September 16, 2016
Division Six Construction
Attn: Randy Fischer
2636 Davos Trail
Vail, Colorado 81657
randy@divisionsixconst.com
Project No. 16-7-352
Subject: Observation of Excavation, Proposed Garage Addition, 2636 Davos Trail, Lot 2,
Block C, Vail Ridge, Vail, Colorado
Gentlemen:
As requested, a representative of H-P/Kumar observed the excavation at the subject site on
September 9, 2016 to evaluate the soils exposed for foundation support. The findings of our
observations and recommendations for the foundation design are presented in this report.
Hepworth-Pawlak Geotechnical (now H-P/Kumar) previously conducted a subsoil study for
design of a retaining wall foundation at the site and presented our findings in a report dated June
13, 2016, Job No. 116 205A.
The garage addition will be attached to the uphill, northeast corner of the residence. Spread
footings placed on the natural soils and sized for an allowable bearing pressure of 2,000 psf were
designed for the garage foundation support.
At the time of our visit to the site, the perimeter trench foundation excavation had been cut in 3
levels from 4 to 8 feet below the adjacent ground surface. The steps in grade were between
about 2 to 5 feet and generally down to the southeast with the slope of the adjacent ground
surface. The soils exposed in the bottom of the excavation consisted of stiff, sandy silty clay
with gravel. Results of swell-consolidation testing performed on a sample taken from the site,
shown on Figure 1, indicate the soils are slightly to moderately compressible under conditions of
loading and wetting. No free water was encountered in the excavation and the soils were moist.
The soil conditions exposed in the excavation are generally consistent with those previously
encountered on the site and suitable for support of spread footings designed for the
recommended allowable bearing pressure of 2,000 psf. Loose disturbed soils in the footing areas
should be compacted or removed to expose the undisturbed natural 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
Division Six Construction
September 16, 2016
Page 2
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,
H-P: KUMAR
i�j�i �4 a-4 t.
Steven L. Pawlak, P.-. s di 5 2 2 2
SLP/ksw te • �
Attachment: Figure 1 —Sw- ., -- •tion Test Results
H-P KUMAR Project No. 16-7-352
Moisture Content = 15.5 percent
Dry Density = 106 pcf
Sample of: Sandy Silty Clay
From: Bottom of Excavation. Garage Area 9/9/16
0
1
No movement
0 • upon
wetting
c 2
0
0
3
4
•
•
0.1 1.0 10 100
APPLIED PRESSURE-ksf
16-7-352 H-P` KU MAR SWELL-CONSOLIDATION TEST RESULTS Figure 1