Report Mein Office San. Office Bend Office
Carlson Testing, Inc. 8430Si( Hmaib 4060 Hudson .54, NE 6302508 Rilry Rd6/1
Tigard OR 97113 Salon OR 97301 Bend, OR 97701
Phone: (503/ 661 -3160 Phone: (503) 5891151 Phone. 1541) 3309135
Construction Materials Testing & Inspection Far. 13031 644-0954 Far 15031 5894309 For 15411 330-9163
•
Special Inspection
FINAL SUMMARY LETTER
June 21, 2006
T0508516H
City of Tigard
13125 SW Hall Blvd.,
Tigard, OR 97223 -8199
Attn: Building Department
Re: Arbor Summit- Lot# 17
14988 SW Lookout Drive- Tigard, OR
Permit# MST2005 -00408
Dear Sir or Madam:
This is to certify that in accordance with Section 1704.1.2 of the International Building Code, we have performed special
inspection of the following item(s) per our inspection reports only:
Installation of Adhesive Anchors
All inspections and tests were performed and reported according to the requirements of Project Documents and, to the
best of our knowledge, the work was in conformance with the approved plans and specifications, approved change orders
and applicable workmanship provisions of the State Building Code and Standards, as well as the structural engineer's
design changes, approvals and verbal instructions.
Our reports pertain to the material tested /inspected only. Information contained herein is not to be reproduced, except in
full, without prior authorization from this office.
If there are - ' further questions regarding this matter, please do not hesitate to contact this office.
Respectfu / ; submitted,
CARLSO TESTING, IN .
I , ,.
Jame: . Hietpas
Opei: tions Manager
J - /ks
Arbor Custom Homes- Wyatt Jean Faivre
I • Froelich Consulting Engineers
Pollard Hosmar & Associates
Jan. 26. 2006 9:47AM MS Zoos - OOyo$ No, 1958 P. 1/4
I '9ee Si.) Lootcc r L 1 4.
1_04" I 1 MQce soMM r COOP IN
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Real -World Geotechnlcal Solutions
Investigation • Design • Construction Support
January 26, 2006
Project No. 04 -8608
Terry Kinney / Jim Cavanaugh
West Hills Development
15500 SW Jay Street �
Beaverton, Oregon 97006 c)te.c° *6
Fax No. (503) 641 -7661 \ �P � `'
fc1. ‘0
ANA
Copy: Froelich Consul jng Eng (Fax 503- 624 -7005) G1' N SAO
Wyatt Field Office (Fax 503 -524 -4403) $e(9
Subject: Geotechnical Observation of Foundation Excavation and Consultation
Arbor Summit Lot 17 —
Tigard, Oregon
References: 1. Preliminary Geotechnical Engineering Report, Oregon State University Property,
12780 SW Bull Mountain Road, Washington County, Oregon, GeoPacific
Engineering, Inc. report dated February 17, 2004.
2. Preliminary Geotechnical Engineering Report, Arbor Summit, 12950 SW Bull
Mountain Road, Washington County, Oregon, GeoPacific Engineering, Inc. report
dated May 24, 2004.
3. Summary Report of Geotechnical Observation and Testing, Arbor Summit, Tigard,
Oregon, GeoPacific Engineering, Inc. letter report dated September 8, 2005
At your request, GeoPacific Engineering, Inc. (GeoPacific) performed a geotechnical review of the proposed
residential construction on Lot 17 of the Arbor Summit development. The location of the subject lot is shown
on the attached plan. GeoPacific performed geotechnical studies for the project (References 1 and 2), and
provided on -call testing and construction observation services during mass grading. Results of our observation
and testing are presented in our report dated September 8, 2005 (Reference 3).
Lot 17 is underlain by engineered fill, with on -call monitoring and testing performed by GeoPacific. The
proposed development on Lot 17 consists of a two -story conventional timber - framed residence. The garage
floor will be elevated as will the living space, with a crawlspace beneath. GeoPacific visited the site on January
24, 2006 to observe foundation excavations.
The existing lot grades slope down toward the south. Building plans for Lot 17 call for square column footings
to support the elevated garage floor. Unfortunately, during foundation excavation, the toe of the slope was
overexcavated such that some of the square column footings would be near the edge of a vertical excavation
extending about 6 feet down to the lowest bench of the foundation excavation. Following discussion of various
options, it was decided the most effective method for dealing with the situation would be construction of a
7312 SW Durham Road Tel (503) 598 -8445
Portland, Oregon 97224
Fax (503) 59 8-8705
Jan. 26. 2006 9:47AM No. 1958 P. 2/4
- January 26, 2006
Project No. 04-8608
monolithic strip foundation extending down the entire slope, including the vertical cut that has been
overexcavated at the toe.
For design of this option, GeoPacific recommended using an allowable soil bearing pressure of 2,000 psf, active
earth pressure of 30 pcf acting on vertical elements of the foundation system, and ultimate friction coefficient
0.5.
Froelich Consulting Engineers developed the attached foundation plan for the affected area, which we
understand incorporates the recommended soil parameters. This foundation plan is in our opinion consistent
with the geotechnical recommendations and may be implemented.
Results of our site visit indicate that the remainder of the footings have adequate embedment depth
(minimum 12 inches), and that adequate footing -to -slope setback distances have been maintained. In
our opinion, the observed subgrade conditions on the subject lot are adequate to support an allowable
bearing pressure of 2,000 psf. Where stepped foundations are present, a 1 H:1 V setback should be
maintained to avoid surcharging of the lower foundation wall.
Care should be taken to avoid saturation or disturbance of footing subgrade soils during and after
excavation. If footing bearing soils become saturated or disturbed, any softened soil or slough should
be removed and replaced with crushed aggregate or additional concrete. In general, footing
excavations should be cleaned such that no more than about 1 /2 inch of loose soils are present prior to
pouring concrete.
This foundation excavation review should be considered supplemental to the above - referenced
geotechnical reports. The conclusions, recommendations, uncertainties and limitations of those reports
remain applicable, except where modified herein.
We appreciate this opportunity to be of service.
•
Sincerely,
GEOPACIFIC ENGINEERING, INC.
r PRO
14- 144
Scott L. Hardman, P.E.
Principal Geotechnit al Engineer �' - • 1 0.,r—
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EXPIRES: 06 -30 -2002_ i
0 8 608.Arbor Summit Lot 17 2 GEOPACIFIC ENGINNEERING,1NC.
Jan. 26. 2006 9:47AM No. 1958 P. 3/4 •
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Jan. 26. 2006 9:47AM No. 1958 P. 4/4
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FRO ELICH 503.644,7005 PROJECT,
CONSULTING z S o .... • SUice 101 PROJECT NUMBER,
ENGINEERS FAX S41.383:7690 ° "M'
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