Report Main Office Salem Office Bend Office
P.O. Box 23814 4060 Hudson Ave., NE P.O. Box 7918
c 1� Testing, gard, Oregon 97281 Salem, OR 97301 Bend, OR 97708
C a rl s o i Inc. I Phone (503) 684 -3460 Phone (503) 589 -1252 Phone (541) 330 -9155
FAX (503) 684 -0954 FAX (503) 589 -1309 FAX (541) 330 -9163
Special Inspection ' h o f (� 5S ' _ - CO3-7.3
FINAL SUMMARY LETTER
July 26, 2000
G9801757 RF,c _ .. - __
I
City of Tigard JUL 2 7 2000 1
13125 SW Hall Blvd.,
Tigard, OR 97223 -8199 BY:
Attn: Tom - Building Department
Re: Pacific Utility Trailer
12805 SW 77 Place, Tigard, OR
Permit No.: 1,P98:0373 --e ''' --e '''
Dear Sir:
This is to certify that in accordance with Section 1701 of the Uniform Building Code and Chapter 24.20,
Title 24, we have performed special inspection of the following item(s) per our inspection reports only:
Reinforcing Steel
Concrete — Compressive Strength Testing
Structural Masonry
Installation of High Strength Bolts
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 any further questions regarding this matter, please do not hesitate to contact this office.
Respe fully submitted,
C ° RL`ON TESTING, INC.
/ / O/
�- ' ., Hietpas
• J : i I, Assurance Manager
H: +k
cc: GFC Construction — Geoff
Walker Diloreto Younie, Inc.
P: \WORD \REPORTSIFINLTR\G9801 757
Main Office Brach Office
P.O. Box 23814 4060 Hul.lsan Ave., NE
Tigard, Oregon 97281 Salem 0 I Si7301
C :'Destine, Inc.
Phone (503) 6134.3460 Phone (,iO3 589-1252
.�..► FAX (so3) ss -ossa FAX (5(3) 569-1309
October 21, 1998 D �A , n�
CTI 096-G1757
GFC General Contracting
17017 Cana( Circle
Lake Oswego, OR 97035
DISCUSSION OF LIQUEFACTION POTENTIAL AND SOIL STRENGTH LOSS
PACIFIC UTILITY TRAILER BUILDING ADDITION - HUNZ!KER ROAD
TIGARD, OREGON
Pursuant to your request, an engineer from Carlson Testing, Inc. ICTII has reviewed the tit
and proposed construction with regards to reviewing the dynamic soil response during seis:ni
events. The proposed construction is a single- story, steel framed bu !ding with a concret
slab -on- grade. thickened footings around three sides, and a Std 9 foot tell cantilever concrete
retaining wall along the back side.
The primary purpose of this letter Is to address the soil iiquefactior hazard, its pater l:iEI
detrimental effects on the structure, and to present recommended mitigating measures. '"h
site is underlain by fine- grained silt soils classified as ancient flood deposits (Off). Beset oil
the DOGAMI Open File Report No. 0 -90 -2, the site is underlain by eboet 60 feet of Qft a ver
400 feet of very stiff undifferentiated iacustrine sediments over basement rock consietine of
Columbia River Basalt. Based an our extensive experience with nearby sites containing
ancient flood deposits, the Off has a high potential for liquefaction generally at a depth of
about 10 to 20 feet below original grade during a very large seismic event (0.34g PGA he ail
event recurrence interval every one thousand years or a 5% chance of occurrence in next 51)
years), For the code required design event which hes PGA of 0.24g end a recurrence inter yr 1
of every 500 years or a 10% chance of occurrence in the next 50 years, the potential for
damaging liquefaction is only considered law to moderate.
If liquefaction should occur, we do not expect a significant loss of bearing strength within th��
zone of influence beneath the spread foundations, nor do we expect that significant Iat::, 1
spreading would occur. Seismic induced settlement is estimated to range between one t )
three inches. Given the type of structure, although the estimated settlements could ca axe
significant damage to the structure, the effective hazard to occupants is considered minimal.
To mitigate seismic induced settlement, after performing deep subsurface explorations, wpm-
cast piles could be drilled to a depth below any expected liquefiable layers. This we ulr l
mitigate settlement below the foundations, but not beneath the slab -on- grade. The projec terl
extra costs for design and construction are estimated to be between $30,000 to $50,0$0.
The decision to mitigate against liquefaction is the responsibility of tl"e owner.
Uct. '_ice C:ii F'. 0
1 #98 -G1757
Page 2of2
This letter is based on our best understanding of the types of deposits at the site and state ti-
the-art evaluation of dynamic behaviors of silts. No deep detailec investigations vier
performed specifically at the site, Information contained herein is rct to be reproduced,
except in full, without prior authorization from this office. If there are any further question:;
regarding seismic hazards, please do not hesitate to contact this office.
Respec • • itted,
• C - c.
td 14743 r
P.-
� - OREGON
'do v4� 23 , ,g� �s.
es 0, itAS
James D. Im.rie, P.E., C.E,G.
Principal Engineer
P.O. Box 23814
j Special Inspection Tigard, Oregon 97281
gos / Phone (503) 684 -3460
1 FIELD REPORT 1 , FAX # 684 -0954
PROJECT I PO v t'U DATE: 9 Z 3 5 6
JOB ADDRESS: C O L / 471 ' 6-7 /g -
Z (IGMW 'TYPE OF INSPECTION: R' KY CC A--
PERMIT NO.: (J? 55 - O3 - 73 LAB. REPORT NO.: 7 c
WEATHER:
Inspection Notes: (Include location, testing data, substitutions /deviations, materials and methods of construction,
conformance statement, etc.
30A) ■c/ 6.-■ i ,1 /7-
, 30 - 3c>c 21) /k)
60/1-,
(A) aiiureizi/A>0-0_,
T , c ) ! )07 c 5 - Z , e 0z-
W/ a1/7(,& C C U cOc ( f R4)
■
r� /)t, - (2/ ZI Ct J ,
0-0a)7" 1r7d/1 2- g i ` - - � U,'L- ccki
l /Cam- / r / itt& c 1'� 'O 7o ' � 0/ 0 V fsr !vim
vr, 5 cc0 41'
Time Arrived: Inspector:
Time Left Job: Certification No.: C'7 (/ -
Information contained herein is not to be reproduced, except in full, without prior authorization from this office.
SEP -11 -94 11:19 PM
Main Office branch Office
Box 23814 40E0 Hudson Ave., NE
Tigard. Oregon 97281 Salem, OR 97301
Carlson Testing, Inc. Phone X503) 684 -3460 Phone (503) 589 1252
FAX (503} 68:-0954 FAX (503) 589.1309
September 10, 1998
CTI #98-G1757
GFC General Contracting
17017 Canal Circle
Lake Oswego, OR 97035
GEOTECHNICAL REVIEW FOR RETAINING WALL CONSTRUCTION
PACIFIC UTILITY TRAILER BUILDING ADDITION - HUNZ!KER ROAD
TIGARD, OREGON
Pursuant to your request, an engineer from Carlson Testing, Inc. (CTI) has visited the above
referenced building addition with regards to reviewing the soil conditions for the proposed
cunstruciion of a 6 to 9 foot tall cantilever concrete retaining wall that will be a part of the
warehouse -type building wall on the east end of the property. The purpose of our review was
to note the soil conditions and provide recommendations for design of this new wall.
The existing soil conditions exposed in the cut were fine grained flood deposits (brown SILT)
that are typical of the Portland area. The central portion of the Cut was wet and has softened
because the silt has no clay and the groundwater seepage is causing the soil grains to
essentlully float.
We recommend thot the center 75 feet be overexcavated e depth of 2 feet and backfilled
immediately with one foot of 1 Yz "-% crushed drain rock and one foot 1'Y " - crushed
aggregate base rock compacted to at least 90 percent of the modified Proctor maximum dry
density. Replacement with compacted gravel should be performed quickly so that the weight
of the gravel is in place before the soil is allowed to soften. Once the overexcavation work
is performed, the allowable bearing at the base of the wall is 2,0001b/ft The equivalent -fluid
active pressure for a well drained wall is estimated at 55 Ib /ft
The coefficient of friction between soil and concrete may be taken as 0.35; however we
suggested placing at least a 4 -inch thick layer of lightly compacted 1 Y2" crushed aggregate
base over the subgrade over in areas not recommended for overexcavation. This should
improve the coefficient of friction to at least 0.48. Passive resistance may be assumed at 300
lb/ft
Information contained herein is not to be reproduced, except in full, without prior authorization
from this office. If there are any further questions regarding this matter, please do not hesitate
to contact this office.
Respectfully ,submitted, ��s �tiGl Ef fy ` ' o
CARLSON TESTING, INC. �o �' ^r
mo 11:;43 Ir
James D. rmbrie, r'.E., C. e. v Principal Engineer ,,_ 23 19 4.
'' ES D. ltr� C y • 0 - k
4