HomeMy WebLinkAboutObservation of Excavation 02.09.2015Yeh and Associates Inc.lït Consulting Engineers & Scientists
February 9,2015 Project No.213-112
Mr. Chuck Caron
c-coN, LLc
PO Box 1097
Rifle, GO 81650
Subject: Excavation Observation, Proposed PDC 300 Building, Divide Road Water
Facility, Garfield County, Colorado.
Dear Mr. Caron,
As requested, a representative of Yeh and Associates, lnc. observed the excavation at the
subject site on February 9,2015 to evaluate the soils exposed for foundation support. The
findings of our observations and recommendations for the foundation design are presented in
this report. The services were performed in accordance with our agreement for professional
services to you under Job No. 213-112.
We understand the proposed building is called the PDC 300 building and is located within the
Divide Creek Water Facility. At the time of our visit to the site, the foundation had been
excavated to a depth of approximately 48 inches below existing grades. The exposed surface
material appeared to be broken sandstone bedrock which extended to the foundation depths.
Approximately 6 to 12 inches of base course was placed and compacted at the bottom of the
excavation as a leveling course. No free water was encountered in the excavation.
According to our geotechnical engineering report dated June 10, 2013, main structure
foundations can be designed for a maximum allowable soil pressure of 2,500 psf, and other
foundations at the project site can be designed for a maximum allowable soil pressure of 4,500
psf. We understand this structure to fall in the 4,500 psf category as it was not named
specifically in the above mentioned report.
Based on our observations of the completed foundation excavation, the subgrade appears to be
generally consistent with soils referenced in the above report which are capable of providing an
allowable bearing capacity of approximately 4,500 psf. We did not verify bearing elevations or
excavation depths as part of our observations.
We trust that this provides the information requested at this time. lf you have any further
questions, please contact our office.
Sincerely,
YEH AND ASSOCIATES, INC
þ";r-*-
ScottW. Richards, P.E., P.G.
Colorado Northwest Region Manager
2000 Clay Str€et, Suite 200, Denver. CO 80211, (303) 781-9590, Fax (303) 781-9583
1525 Blake Avenue, Glenwood Springs, CO 81601, (970) 384-1500, Fax (970) 384-1501
588 North Cornrnercial Drive, Grand Junction, CO 81505 (970) 242-5 125, Fax (970) 255-8512
570 Turner Drive, Suite D, Durango, CO 81303, (970) 382-9590, Fax (970) 382-9583
Yeh and Associates, lnc.
Proiect Diary,ül
Project Number
213-113
Project Name
Divide Road Water Facility
Date:
02t09t2014
Page I
Time Arrived on Site
11:00 am
Time Left Site
11:45 am
Weather
Partly Cloudy
Approx. Temp ('F)
46
B¡llable Miles:
137
Nuclear Gauge (lD No., Std Counts (Density and Moisture)
N/A
Other Test Equipment (Desc and Serial No.)
S¡gned
Stu McClaskey
Title: Observer
ENG. TECH
Location Station: PDC300 Bldg.
Equipment on Site
ïrack hoe
CAT Loader
Walk behind sheep foot roller
Upright Tamper
Personnel and Company on site:
Jack w/ CCON
Discussion Log (With Who, Discuss¡on Summary)
Jack w/CCON
Observations (Specification, Observation) :
Upon arrival today CCon had 4 holes opened up for the proposed PDC 300 building. The contractor encountered hard sandstone dur¡ng the
excavation from surface to approximately 48"in depth, base course in depth oÍ y." to 1" was placed and compacted for a leveling coarse.
3'd hole form the East
West hole
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