Report (88) •
Carlson Geotechnical Bend
Office
Office (541)345-0289 1' : f (OA.
Eugene
A Division of Carlson Testing, Inc. Salem Office (503)589-1252 GEOTECHNICAL
Phone: (503) 601-8250 Tigard Office (503)684-3460
Fax: (503)601-8254
Final Summary Letter—Geotechnical Services RsV.� V\—k Gc\ -
October 18, 2018 `i
McPherson Contractors Inc. —Jeff Heit
3501 SW Fairlawn Road U k.k
Topeka, Kansas, 66614
Final Summary Letter of
Geotechnical Construction Observation Services
Natural Grocers -Tigard
CGT Project Number T1803518
Permit No.: BUP2017-00184/SIT2017-00013 (SITE WORK)
1.0 OVERVIEW
Carlson Geotechnical (CGT), a division of Carlson Testing (CTI), served as Geotechnical Engineer of Record
(EoR) for the Natural Grocers — Tigard project. The site is located at 13125 SW Pacific Highway, Tigard,
Oregon. As geotechnical engineer, we performed a geotechnical investigation of the site, the results of
which were presented in our "Report of Geotechnical Investigation — Tigard Specialty Food Store" dated
March 11, 2015. One Geotechnical Memorandum was issued on July 23, 2016 to provide recommendations
for the bike lane and entrance pavement design section.
2.0 GEOTECHNICAL CONSTRUCTION OBSERVATION AND TESTING SERVICES
We performed geotechnical construction observation and testing services during site grading/foundation
excavation, building pad development, utility installation, and prior to installation of curbs and gutters. These
services were conducted on an on-call, part-time basis between January 15, 2018 and August 29, 2018. Our
site visits were scheduled by the site superintendent for McPherson Contractors Inc. Copies of our field
reports were forwarded as the work progressed and are available in our office for review. The following is a
summary of our observations:
• Site Stripping: Based on our field observations, the building and pavement areas that we observed were
stripped of surface vegetation, previous pavements and organic topsoil in general accordance with the
recommendations provided in the referenced geotechnical report. In addition, concrete footings and
buried structures (vaults, abandoned utility conduits, etc.) associated with previous structures were
removed from the site in general accordance with the recommendations provided in the referenced
geotechnical report.
• Subgrade Soils: Based on the results of our proof roll observations and probing, the subgrade soils
within structural fill locations that we observed were prepared in general accordance with the
recommendations provided in the referenced geotechnical report.
• Site Grading: Site grading consisted of the placement and compaction of imported granular materials
and reused on-site soils. Based on our proof roll observations, in-place density testing, and observation
of compactive effort, the structural fills observed and tested within parking, drive lane and building
Carlson Geotechnical • P.O. Box 230997, Tigard, Oregon 97281
Natural Grocers- Tigard
T1803518
October 18, 2018
locations were placed in general accordance with the recommendations provided in the referenced
geotechnical report.
• Structural Fill Compaction: Based on our results of proof roll (deflection) tests and density testing using
a nuclear densometer, the structural fill that we observed and tested was compacted in accordance with
the recommendations provided in the referenced geotechnical report.
• Building Foundation Subqrades: Based on our field observations, the foundation excavation subgrades
for the residence/building that we observed were prepared in general accordance with recommendations
provided in the referenced geotechnical report.
• Floor Slab Subqrade: Based on our observations, the floor slab subgrade soils that we observed for the
building were prepared in general accordance with the recommendations provided in the referenced
geotechnical report.
• Pavement Subqrade Soils: Based on the results of our proof roll observations, the pavement subgrade
soils we observed in the new parking lot and entrance areas and within portions of School Street west of
the site frontage were prepared in general accordance with the recommendations provided in the
referenced geotechnical report.
• Pavement Base Rock: Based on the results of our proof roll observations and density testing, the
pavement base rock that we observed within the new on site pavement areas, and within portions of
School Street and SW Pacific Highway, was prepared in general accordance with the recommendations
provided in the referenced geotechnical report and project plans.
• Utility Trench Backfill: CGT observed the placement and compaction of backfill within stormwater utility
trenches on the site. Based on our observations and testing using a nuclear densometer, the utility
trench backfills that we observed were compacted in general accordance with the recommendations
provided in the referenced geotechnical report and project plans.
Based on our observations, as documented in our field reports, and to the best of our knowledge, within our
scope of work, the above geotechnical summaries accurately reflect our observations and testing. Our
services were provided on an on-call, part-time basis, in which we relied on the contractor to contact our
office for the scheduling of our services. We cannot be held contractually responsible for those items, if any,
that we did not observe or test.
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Carlson Geotechnical Page 2 of 3
Natural Grocers- Tigard
T1803518
October 18, 2018
3.0 CLOSURE
Should you have any questions regarding the information presented in this report, please contact us at (503)
601-8250.
Sincerely,
CARLSON GEOTECHNICAL
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William M. Weyrauch, P.E., G.E.
Senior Geotechnical Engineer
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Note: The observations of conditions at the times of our site visits were based solely on visual methods. Our
reports pertain to the locations observed at the times of our visits only. Information contained herein is not to
be reproduced, except in full, without prior authorization from this office. The information contained in this
report is provided subject to all terms and conditions of CGT's General Conditions in effect at the time this
report is prepared. No party other than those to whom CGT has distributed this report shall be entitled to use
or rely upon the information contained in this document.
Distribution: McPherson Contractors Inc. —Jeff Heittf2 cz me ahersonbuild,cam
McPherson Contractors Inc.—Jaclyn Gillespie jaclyng@mcphersonbuild.com
McPherson Contractors Inc.—Jon Riley ronr(c mcphersonbuild.corn
City of Tigard—Walter'Chip' Barnett walter{ tietprd-or.ctov
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Deliverables\Final Letter\Final Summary Letter T1803518.docx
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