01575a
1. 114TRODUCTIO!+
A geotechnical investigation has been completed and the results
are presented herewith. The purposes -of this investigation are
as follows:
a) to delineate subsoil condition,
b) to delineate slope stability conditions of the existing slope,
c) to recommend foundation type, basement wall pressure, and
wall drainage.system.
An authorization to proceed with this investigation was made by
Mr. Dennis Mortensen of 01son Walker Associates on April 7, 1980.
2. PROPOSED DEVELOPMENT
Fourteen unit multiple family residences are planned for all five
lots in the subject property. it is understood than cne two story
structures will be built with.daylighted basements. Some terrace {
foundations and floors are also contemplated. A high retaining
wall which may be as high as 15 feet was also contemplated for the
proposed structures'on the subject properties.
3.' SURFACE FEATURES
In general, the site is covered with weeds, underbrush, fir, cedar
and maple trees. The existing street 2nd Avenue cul-de-sac is located'.
east of the proposed site (see Figure 1). A shallow natural creek
is located on west part of the proposed building areas. The height
of the bank is approximately 15 feet from the bottom of the creek.
The bank slope in the site is stable with some minor erosional scars.
The existing slope -angle is almost 2H:1V or safe against a potential
deep seated landslide.. No noticeable seepage .flow was noted on the
bank along the creek.. The general site topography is gently downsloped
westwards.
4. SOIL EXPLORATIONS
Field evaluations of subsurface conditions were hased on observation
of test pits dug on the site at loca.tions.shown in Figure 1. The soils
were visually classified in the field froii, examining soils that
were exposed on the test pit walls. Detailed soil logs are presented
in Figure 2 and 7.
The following is a summary of the generalized stratigraphy noted at
the site.