HomeMy WebLinkAboutPermit Field Test & Inspection Report 2000-11-6
fC I . ~q
FORD ~ '1:55 ~ =A553-'1~:R
LAND SURVEYING . CONSTRUCTION SUPERVISION . WATER RIGHTS EXAMINATIONS
November 6, 2000
Bruce Wiechert Custom Homes, Inc
3375 Park Hills Dnve
Eugene, Oregon 97405
Attention Mr Dernck Westover
RE: Subgrade Evaluation
909 So. 67th Street
Springfield, Oregon
Permit No. 00-05284-01
On November 6, 2000, an engineer observed and hand-probed the subgrade exposed on the
above referenced residential bUilding pad to assess beanng capacity and shrink/swell potential
of the soil The follOWIng observations and recommendations are presented to assist In the
foundation and drainage design for the residential structure
The building lot is located on a northwesterly sloping site The rear of the lot has been cut Into
the hillSide exposing an approxImately 5-foot high vertical face of the near surface sOIls The
upper 2 feet of the site IS comprised of dark brown soft topsoil underlain by varying degrees of
weathered basalt. The building Will have tiered foundation with the majority of the liVing space
on the uphill side of the structure The exposed subgrade at the time of my site viSit IS sUItable
for an allowable bearing capacity up to 1,500 psf
I recomm~nd that 12-inches of crushed aggregate be placed over the subgrade immedIately
after excavation to stabilize the mOisture content of the subgrade soil and mitigate the potential
for sOil shrink/swell. The aggregate shall be compacted to at least 95% of its maximum dry
denSity as determined by AASHTO Method T-99
Adequate subsurface drainage of the bur/ding site is imperative. During the site ViSIt, a 3-lnch
dIameter drain-pipe with a filter sock was placed around the perimeter of the building pad and
Will be covered With open graded aggregate A drain should also be placed adjacent to the
base of the footing. A typical footing drain detail IS attached. I recommend that landscaping
and soil adjacent to the foundatIons be sloped to direct surface water away from the structure,
roof drain should outlet to the street and water should not pond adjacent to footings
Ronald J Derrick P
--,./ Pnnclpal Engineer
.. ~ .. .
~
RET WALL
///-<--\'<//
/~
~\Y(//
12"
IMINI
0f7/
@~
r--=-----,
100 00"01
"0 l> O' 0001
I fl' C ~
I LJ C> /l 0
IDD (}oc'l~
o I) j ~
I 0 .0 0 I ~
p ,Co D () I ~
I ~ 0 0 .~ 0 (
Il() 0 AO. 0 () I
II, U <J ,6. I
L.:=..., Cl /-- I rl"
J o\~Y I ---L
\.:__=7
/I/~'o/
..
PROPERLY
;;:- COMPACTED BACKFILL
///~~'o/
~ -%" CRUSHED ROCK
H
2/3 H .
. --=- - FILTER FABRIC ENVELOPE
3" DIA. PERFORATED A B S
OR ADS PIPE
NO SCALE
RETAINING WALL DRAIN DETAIL