Plans NOV -06 -1997 17:53 5032480223 503 248 0223 P.01'02
1.
• i• \ a:.•ti E w a i... v :l. ..
PBS 50-' Q7-- 00
ENVINONNLNT•L
November 7, 1997
Mr. John B. McCroskey
do Meadowlark Partners
Attn: Mr. Dave Lintz
. 1750 SW Skyline Boulevard, Suite 224
Portland, OR 97221
RE: PROPOSED DENTAL CLINIC
SW 69 AVENUE
TIGARD, OREGON
Dear sirs:
At your request, and in general accordance with our proposal dated October 30, 1997, an abbreviated .
scope of design phase work has been completed. The purpose of this work was to review available
subsurface data in the vicinity of the proposed dental office, and render a professional opinion of the
probability of the subsurface soils to liquefy when subjected to design level shaking (0.3g peak
acceleration).
Test pit information, and our experience with sites in the vicinity of the proposed development
indicate that liquefaction of the upper 8 feet of subsurface soils is not probable, in my opinion; i.e.,
direct bearing failure of spread footings is not probable.
All persons should be aware that a geotechnical literature review of available data may or may not
reveal the seriousness of geotecimical risks. Inasmuch as no subsurface explorations were performed
for this assessment, we can only offer you opinions based upon our review of the available data, and
ENVIRoNtAtNTAL
MANAGEMENT
AND CONSULTING
1220 SW Mogpwn Glut. Suitt Epp Vonlaad. OR 97ZOS 303/248 -1939 Fax 303/2484227
DENVr* xu6LNL PORTLAND VCRs AND SEATTLE
NOV-08 -1997 17:54 5032480223 503 248 0223 P.02/02
Bob McCroskey PBS # 12189.03
RE: Proposed Dental Office
November 7, 1997
Page 2, 1997
supplemented to some extent by technical knowledge and any past experience with this formation in
the general area of the site. Thus, if we do not note specific hazards existing on the property at this
time, it is not a guarantee or assurance that no hazards exist or will be found to exist in the future.
In any event, additional geotechnical work is recommended during design and construction of the
facility. The scope of the work should at a minimum include Plans and Specs Review and
construction observations and testing of foundation bearing surfaces and structural earthwork.
If you have any questions, please call me at 248 -1939.
Sincerely, � ' r 'o
a 15,951
/ �' . ,OREGON 9
P 21 1 9
44ri P. 8E- 4
Alan P. Bean, P.E.
Senior Geotechnical Engineer
TOTAL P.02