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G E° ESIGN_ FIELD REPORT
Page 1 of 5
GDI Project: Polygon-129-03 Prepared By Kyle Hanson
Project;Name: River Terrace East Date:
May 17 2018
Locations SW Scholls Ferry&Roy Rogers,Bvrtn. Report#: 226
Arrival: 0930 Departure: 1030
Weather: Overcast, 60's Permit#: TBD
Site Visit Requested By: Brian (Polygon), Ken (Polygon) Met With (on site): Brian, Ken (via phone),
Earthwork crew
Purpose: Subgrade observation -Lots 104, 105, 173-179
Outstanding Issues: Proof roll road and curb base rock and repair as needed before paving
FR-58 (12/06) -Decommission temporary storm and sewer lines through Tract E
FR-177-Soft fill from slope cut in lots 153, 154 and 155
FR-223 -Large roots/organic wooden debris within lot 165 subgrade
FR-226-Wooden debris within lot 104 footing subgrade
SUBGRADE OBSERVATION -LOTS 173-179
I observed retaining wall subgrade for lots 173-179 where indicated on the attached site plan(s). Subgrade appeared
to consist of moist brown sandy silt with gray mottled silt and was firm/unyielding underfoot. Observed probe
penetrations with a Yz"diameter steel'T' probe indicated generally stiff subgrade conditions today.
LOT 199 RETAINING WALL SUBGRADE OVER-EXCAVATION OBSERVATION
Brian with Polygon asked me to observe retaining wall subgrade for Lot 199 where a failing existing retaining wall
had been removed (see site plan(s)). As per our geotechnical recommendations (see previous field reports), crew
had over-excavated the wall subgrade by an additional foot due to the presence of soft subgrade soils. Brian
indicated that they had also scraped away soft soil from the cut face until firm soil was encountered. I observed that
the over-excavated subgrade appeared to consist of variable brown to gray moist silt and granular backfill within
utility trench(es). Observed probe penetrations(under full body weight)of 6"to 1 Yz' indicated generally stiff to
medium-stiff subgrade conditions today. Based on discussion with Shawn Dimke of GeoDesign, we feel the
subgrade conditions observed today are adequate.
SUBGRADE OBSERVATION-LOTS 104& 105
I observed subgrade for lots 104 and 105 where indicated on the attached site plan(s). Subgrade for each lot
appeared to generally consist of moist brown sandy silt. Approximately 1-2"of crushed rock granular base had
been placed over the subgrade areas. Probe penetrations (through granular base)observed at lot 105 indicated
generally stiff to very stiff subgrade conditions today. Lot 104 subgrade exhibited generally stiff conditions based
on probing.
I observed roots/organic wooden debris protruding from lot 104's subgrade at the approximate areas indicated on
the attached site plan(s)and site photos. I also observed dry/crumbly soil, presumably topsoil,just below the
granular base where indicated on the site plan(s)(outer edge of first cut bench, from bottom -see site photos). I
spoke with Ken via phone call (Polygon)and met with onsite earthwork crew and directed them to the areas of
organic debris and dry/crumbly subgrade. I recommended trimming/removal of roots/organic debris from the
subgrade and over-excavation of 6"at the observed area of concentrated roots (see site plan)followed by placement
of compacted crushed rock backfill.
9450 SW Commerce Circle,Suite 300 I Wilsonville,OR 97070 1503.968,8787 I www.geodesigninc.com
GEODESIGN_ FIELD REPORT
Page 2 of 5
Where dry/crumbly soil was present,crew indicated that the footing (2' wide)to be placed over the area would not
extend widthwise to the poor soil,which was approximately 2-4"wide at the bench's edge. I observed the soil
within the proposed footing width dimension at this area(beneath the granular base)to consist of brown silty sand
that probed stiff under full body weight. Should the footings placed extend to the dry/crumbly soil observed, we
recommend removal and replacement of the soil with suitable structural fill. Crew indicated that the footing would
not cover this soil and also indicated that they would follow our recommendations for root removal/over-excavation
prior to footing pour.
Based on observations, discussion with the contractor and on-site crew, and probing, it is our opinion that the
retaining wall subgrade for lots 173-179 and lot 199 and the subgrade for lots 104 and 105 are being/have been
prepared in general accordance with our geotechnical recommendations except for the areas of observed
roots/organic debris protruding from lot 104's subgrade.
Distribution:
Attachments: Site Plan (2), Site Photos(3)
Reviewed by: SMD
This report presents opinions formed as a result of our observation of activities relating to geotechnical engineering or environmental services.We rely on the contractor to comply with the plans and
specifications throughout the duration of the project irrespective of the presence of our representative.Our work does not include supervision or direction of the contractor,the contractors employees
or agents. Our fine is not responsible for site safety.This field reportis a DRAFT representation of our field observations,testing,and preliminary recommendations.The report can only be
considered final upon review of the GeoDesign project manager,as indicated by initials in the'Reviewed By'section.
Signature:: .el�"."a ~
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9450 SW Commerce Circle,Suite 300 1 Wilsonville,OR 97070 1503.968.8787 I www.geodesigninc.com