Report (17) GEOPACIFIC
Real-World Geotechnical Solutions
Investigation • Design •Construction Support
July 25, 2023
Project No. 16-4108 4/5%2-V21
Stonebridge Job No. 3251
Attention: Andy Thomas
Stonebridge Homes NW LLC
4230 SW Galewood St., Ste. 100
Lake Oswego, OR 97035
Fax 503-387-7615
Email Andy(a�stonebridgehomesnw.com; JimDt stonebridgehomesnw.com;
kristen(a�dmhholdingsco.com
FOUNDATION SUBGRADE REVIEW
LOT 41 RIVER TERRACE CROSSING
15090 SW COOLWATER LANE
WASHINGTON COUNTY, OREGON
Reference: NV5, Revised Summary Letter Geotechnical Construction Observation Services, Phases
1 and 2, River Terrace Crossing, SW Woodhue Street and SW 150th Avenue, Tigard,
Oregon, dated September 30, 2022.
GeoPacific Engineering Inc. visited the site today to review the single-family home foundation
subgrade at the above address. We understand that the proposed building is a two-story home. In
our opinion, the observed subgrade is adequate for support to an allowable bearing pressure of
1,500 psf. The mass grading of the site was observed and tested by others.
At the time of our site visit, the excavation was nearly complete, and soils exposed in foundation
excavation consisted of predominantly rocky fill with angular oversized cobbles and boulders capped
with medium stiff to stiff fill soils that could be probed about 2 to 4 inches with moderate pressure
using a steel `T' bar probe. A 10-foot descending wall is present in the rear yard on is daylight
basement lot and a 2-foot ascending wall along the east side. The wall footing-to-retaining wall was
adequate; the side yard wall should likely be buried upon foundation backfilling. Some structural
backfilling of the basement wall will be required. The expected maximum anticipated total and
differential footing movements (generally from soil expansion and/or settlement) are 1 inch and 3/4
inch, respectively, over a span of 20 feet.
Due to relatively impervious silty and clayey soils encountered throughout the site, all foundations
should incorporate appropriate drainage measures in accordance with the International Residential
Code. Adequate crawlspace drainage is not something that geotechnical consultants can verify; the
purpose of our visit is for observations of foundation bearing conditions only.
Our work scope pertains to a geotechnical engineer's foundation excavation review only and the
conditions existing and exposed at the time of our site visit. Within the limitations of scope, schedule
and budget, GeoPacific attempted to execute these services in accordance with generally accepted
professional principles and practices in the fields of geotechnical engineering and engineering
14835 SW 72nd Avenue Tel(503)598-8445
Portland,Oregon 97224 Fax(503)941-9281
• GEOPACIFIC
Job No. 16-4108
Lot 41 River Terrace Crossing
geology at the time the report was prepared. No warranty, express or implied, is made. If you have
any questions, please call.
Sincerely,
GeoPacific Engineering, Inc.
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James D. Imbrie, G.E.
Geotechnical Engineer
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FOUNDATION CERTIFICATION logo ski
LOT 41 OF "CROSSING AT PULL MOUNTA \", 6,tl +„„tt
CITY OF TIGAD, WASH \GTON COU\TY, OEGON tikeVe,
PREPARED FOR — -
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STONE BRIDGE HOMES NW, LLC
4230 GALEWOOD ST., SUITE 100
LAKE OSWEGO, OR 97035
N SW COOLWATER LANE I
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REGISTERED LOT N89'15'00"E 56.04'
PROFESSIONAL
LAND SURRVEYOR 39 LOT
40
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OREGON j CURVE TABLE
JANUARY 11, 2005
ROBERT D. RETTIG CURVE RADIUS DELTA LENGTH CHORD
60124LS
RENEWS: 12/31/24 C27 15.00' 9040'53* 23.74' N4524'33"W 21.34'
I, ROBERT D. RETTIG, A REGISTERED LOT
PROFESSIONAL LAND SURVEYOR IN NE STATE CROSSING AT BULL MOUNTAIN
OF OREGON, HEREBY CERTIFY THAT I HAVE 41
STAKED NE FOUNDATION FOR LOT 41 OF AKS ENGINEERING & FORESTRY, LLC AK ORwr1: DMR
"CROSSING AT BULL MOUNTAIN' WITH 12965 SW HERMAN RD, STE 100 cHKD: PMR
HUBS AND TACKS ON JULY 31, 2023. TUALATIN, OR 97062 AKS JOB:
P:503.563.6151 F:503.563.6152 aks-eng.com 9531
DWG:9531DSTK 1 LOT 41 FC