HomeMy WebLinkAboutObservation of Excavation 05.29.2019air
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�lecttnicxl an[1lJ�aferials fn ineaers
and Environmental $clenlisis
An Employee Owned Company
5020 County Road 154
Glenwood Springs, CO 8] 601
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
May 29, 2019
Heyl Construction
Attn: Dave Heyl
6560 County Road 335
New Castle, Colorado 81647
d.heyl (lieylcivil.com
Project No. 19-7-117
Subject: Observation of Excavation, Proposed Residence, Lot 3, Block 1, Oak Meadows 3,
TBD Oak Crest Drive, Garfield County, Colorado
Dear Mr. Heyl:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on May 28, 2019 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 provided a subsoil study report for foundation design for the subject property
dated February 5, 2019, and foundation alternative recommendations in a report dated April 26,
2019, Project No. 19-7-117. Compaction testing of below -footing backfill was performed as
requested on May 8 and 28, 2019.
The proposed residence will be a 2 -story wood -frame structure with an attached garage. Ground
floors will be slab -on -grade or structural over crawlspace. The residence was designed to be
supported on spread footings with 3,000 psf allowable bearing pressure on at least 3 feet of
CDOT Class 6 aggregate base course compacted to a minimum of 98% of standard Proctor
density, overlying the natural sandy clay soils, based on our foundation alternative
recommendations.
At the time of our visit to the site on May 28, the foundation excavation was complete and had
reportedly been sub -excavated 3 feet and replaced to footing grades with compacted Class 6
aggregate base course. The excavation was in multiple levels up to about 8 feet below the
adjacent stripped ground surface. Compaction tests performed on May 8 and 28 (attached for
reference) indicate the backfill below footing areas was compacted to at least 98% of standard
Proctor density as recommended. No free water was encountered in the excavation and the soils
were slightly moist to moist.
The soil conditions observed in the excavation are consistent with those previously encountered
on the site and the backfill as placed and tested is suitable for support of foundations designed
for the recommended allowable bearing pressure of 3,000 psf. Other recommendations
presented in our previous reports which are applicable should also be observed.
Heyl Construction
May 29, 2019
Page 2
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. 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.
Thomas J. Westhoff
Reviewed by:
Steven L. Pawlak,
TJW/kac
Attachments: Earthwork * `` = y ... " +'' est Reports (2 pages)
cc: Tamarack Grove Engineering — Tyler Maier tyler.maier@tamarackgrove.com
Kumar & Associates, Inc. Project No. 19-7-117
5020 County Road
Geotechnical and MEmail:
(+A Kumar A ' al and Materials Engineers Associates, Inc. ® Phone: (970)
and Environmental Scientists
Earthwork Compaction Testing Report
Client: Heyl Construction Project No.: 19-7-117
Attn: Dave Heyl
6560 County Road 335
New Castle, Colorado 81647
Project: Residence, Lot 3, Block 1, Oak Meadows 3, TBD Oak Crest Drive,
154, Glenwood Springs, CO 81601
945-7988, Fax: (970) 945-8454
kaglenwood atkumarusa.com
Day: Wednesday
Date: 5/8/19
Page: 1 of 1
Garfield County, CO
Weather: Overcast, windy, dry Temperature: 52° at 4:30 pm
Earthwork Contractor: Heyl Construction
Equipment Used: excavator, plate compactor
Description of Earthwork Structural backfill below footing areas.
Tested:
Verbal Communication: Dave with Heyl Construction
_
Placement and Compaction Procedure: Not observed
by Kumar
Associates
Lift Thickness: Max. Rock Size:
Compactor(s) Used:
Moisture
Conditioning:
Number of Passes:
Nuclear Gauge Moisture/Densl Test Results
Test
No.
'
Location
Depth or
Elev.
Field Dry
Densit
(pcf) y
Field
Moisture
Content
Field
Com
(%) '
Min.
Comp.
Req.
(%)
Proctor
Lab No.
1
20' east of northwest corner of
foundation
grade of
highest step
of footings
131.0
3.8
98
98
United
Sievers
2
north/northwest corner of
foundation trench, center of
trench
grade of
highest step
of footings
137.1
6.4
100
98
United
Sievers
3
W 20' south of north/northwest
corner of foundation
grade of
highest step
of footings
136.0
3.9
100
98
United
Sievers
4
west/southwest corner of
foundation, center of trench
1' below
grade of
highest step
of footings
131.3
3.8
98
98
,
United
Sievers
Proctor Sample Reference:
Lab No.
Method
Description
Max. Dry
Dens. (pcf)
Opt.
Moist. (%)
United
Sievers Pit
ASTM D 698
Class 6 aggregate base course
134.2
8.5
THIS REPORT PRESENTS OPINIONS A5 A RESULT OF OUR OBSERVAT
COMPACTIVE EFFORT AND MOISTURE TO FILL DURING THE TIMES
THE NUCLEAR DENSOMETER METHOD OF TESTING WAS USED IN
Distribution: Heyl Construction - Dave Heyl (d.heyl(ahnvlcivil.com)
Tamarack Grove Engineering - Tyler Maier tyler.rnaier_a'tamarackgrove.com
/kac
IONSOF FILL PLACEMENT,
WHEN OUR OBSERVER IS
SUBSTANTIAL ACCORDANCE
Drew
WE HAVE RELIED ON THE CONTRACTOR TO CONTINUE APPLYING THE RECOMMENDED
NOT OBSERVING OPERATIONS.
WITH ASTM D 6938.
Huemmler . Steven L. Pawlak, P.E.
Field Technician Reviewed By
5020 County Road
Geotechnical and Materials Engineers
(+ilk,(„mar & Associates, Inc.® Phone: (970)
and Environmental Scientists Email:
----•---L
Earthwork Compaction Testing Report
Client: Heyl Construction Project No.: 19-7-117
Attn: Dave Heyl
6560 County Road 335
New Castle, Colorado 81647
Project: Residence, Lot 3, Block 1, Oak Meadows 3, TBD Oak Crest Drive,
154, Glenwood
945-7988,
kaglenwood(c7kumarusa.com
Garfield
52°
Springs, CO 81601
Fax: (970) 945-8454
Day: Tuesday
Date: 5/28/19
Page: 1 of 1
County, CO
Weather: Cloudy, calm, rain overnight Temperature:
at 1:00 pm
Earthwork Contractor: Heyl Construction
below
next to
progress
Equipment Used: Not observed.
Description of Earthwork Structural backfill consisting of Class 6 aggregate base
Tested: footing areas was tested with acceptable results. Tests
footings as footings were in place and foundation wall
at the time of our site visit.
Verbal Communication: None.
course placed
were performed
forming was in
_
Placement and Compaction Procedure: Not observed by Kumar Associates
Passes:
Lift Thickness: Max. Rock Size: Moisture
Conditioning:
Compactor(s) Used: Number of
Nuclear Gauge Moisture/Densit Test Results
Test
No.
Location
Depth or
Elev.
Field Dry
Density ty
Field
Moisture
Content
Field
C10/
Min.
Comp.
Req.
(%)
Proctor
Lab No.
1
10' south of northeast corner
of house
footing grade
131.4
4.6
98
98
United
Sievers
2
Center of south side of house
footing grade
132.2
5.1
99
98
United
Sievers
Proctor
Lab
Sample Reference:
Moist.
No.
Method
Description
Max. Dry
Dens. (pcf)
Opt.
(%)
United Sievers Pit
ASTM D 698
Class 6 aggregate base course
134.2
8.5
THIS REPORT PRESENTS OPINIONS
COMPACTIVE EFFORT AND MOISTURE
THE NUCLEAR DENSOMETER METHOD
Distribution: Hey! Construction
Tamarack Grove Engineering
TJW/
AS A RESULT OF OUR OBSERVATIONSOF FILL PLACEMENT. WE HAVE RELIED
TO FILL DURING THE TIMES WHEN OUR OBSERVER IS NOT OBSERVING OPERATIONS.
OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM D 6938.
- Dave Heyl (d.heylOhevlcivII.com)
— Tyler Maier tvler.maierptamarack irove.com
ON THE CONTRACTOR TO CONTINUE APPLYING THE RECOMMENDED
Steven L. Pawlak, P.E.
Tom Westhoff
Field Technician Reviewed By