skjv final geo.pdf63/1212007 08:15 4258277701 FAX PAGE 02104
Associated Farah. Sciences, Inc.
March 12, 2007
Project No. KE050728A
Soundview Homebuilders, Inc.
9026 6' Avenue South
Edmonds, Washington 98020
Attention: Mr. Ron Den Adel
Subject: Geotechnical Final Letter and Rockery Design Considerations
Permit No. 2006-0195
17035 76`h Avenue West
Edmonds, Washington
Mr. Den Adel;
As requested, Associated Earth Sciences, Inc, (AESI) has prepared this letter in response to a
notice provided to you by the City of Edmonds regarding the above -referenced site. This letter
is based on our previous geotechnical reports and memorandums prepared for the project, and
our observation of earthwork activities at the site. The notice provided by the City, dated
March 7, 2007, included two items of geotechnical significance, as described below.
2. Provide a final letter from the geotech of record stating all requirements were met. Letter
should be wet -stamped and signed by geotech of record,
Based on observation of the earthwork activities related to construction of foundations,
drainage, and rockeries, in our opinion, the project has been completed in general accordance
with the project plans, our geotechnical reports and memorandums, and our field
recommendations. Upon observation of site-specific soil conditions, and at the request of the
owner, AFSI reviewed and agreed with substitution of rockeries in place of mechanically
stabilized earth (MSE) block walls at the back of the house. To our knowledge, this was the
only substantial deviation from the site grading plan.
4_ Provide structural calculations for rockery from geotech of record.
The rockery constructed on the north side of Lot 2 was constructed per the attached detail. As
per out geotechnical engineering report for the site, dated February 3, 2006, the following
information is pertinent to the requirements of the City of Edmonds, Section 6 of Handout #63:
"land Offia.• 911 F",.idi Avenue, Suite 100 • KAimA WA 98033 + P 1(425) 827 7701 + F (425) 827-5424
Event 010m • 2911 112 Hewk Atirenm &gw 2 • Eveett, WA 98201 ■ P 1(425) 2.59-0522 • F J (425) 252-3408
03/12/2007 08:15 4258277701 FAX PAGE 03/04
Soil Classification:
Allowable Bearing Pressure:
Active Earth Pressure:
Passive Earth Pressure:
Coefficient of Friction:
Seismic Loads (per IBC 2003):
Water Table Information:
Maximum Slope Behind Rockery:
Rock Specifications:
Pre -Fraser Glacially Consolidated
USC: SM -ML
1,500 pounds per square foot (psf)
40 pounds per cubic foot (pcf) unrestrained
55 pcf restrained
250 psf
0.35
Period = 0.2 seconds: 1.22g
Period = 1 second: 0.438
Minor seasonal seepage at 2 feet
2H: IV (Horizontal: Vertical)
See attached detail
Based on experience, we would estimate the moist unit weight of the native soils to be
approximately 135 pounds per cubic foot (pcf). To our knowledge, there are no additional
surcharges applied to the rockeries.
The rockery was placed against a stable cut slope with a maximum height of 4 feet. The
rockery is in place to reduce the risk of erosion and provide protection to the slope cut. The
rockery is not intended to retain the slope.
We appreciate the opportunity to be of service to you on this project. Should you have any
questions regarding this letter or other geotechnical aspects of the project, please call us at
your earliest convenience.
Sincerely,
ASSOCIATED EARTH SCIENCES, INC.
Kirkland, Washington
�/q Wash?:
T4 gmoeftg64 70
Liu
Jon N. Sondergaard, P.G., P.E.G.
Principal Engineering Geologist
Attachment: Unreinforced Rockery Detail
7
X284 f
EXPIRES 2 I b f
Matthew A. Miller, P.E.
Associate Engineer
INSlld - KBD5729A 1 - Pt0jWs aoW0728kXMWP
03/12/2007 08:15 4258277701 FAX PAGE 04/04
No roadway, parking lots
or building footings
in this area
' Min.
2 or flatter)
1 }J
Min. 164 f
(lin. 1' wide layer of 2"-4" quarry
spalls adjacent to rockery
Stable cut face in natural material
r'
(See note 5)
� Q
..F
I" (or less) diameter washed gravel
min. 6' cover over pipe,
° 2" grovel under pipe
�— Min. 4" diameter perforated
Firm undisturbed soil rigid PVC pipe. Min. 1% continuous
(See Note 2) slope to outlet
NOTES:
1. Rockeries higher than 5' shall be constructed of rocks of graduated sizes from 5–man to 2–man,
from bottom to top. Rockeries of 5' or lower shall be constructed of 3–man to 2–man, from
bottom to top.
2. Inspection of subgrade, placement of base course and drainage, and finished rockery by engineer -
is required.
3. Rock small be sound and have a minimum density of 160 pounds per .cubic foot.
4. The long dimension of all rocks shall be placed perpendicular to the wall, Eachrock rock should .bear on
two rocks in the tier- below.
5. Rockeries are erosion --control structures, not retaining walls. Natural material mi
free standing in cut face. Maximum height of 3 feet for rockeries facing fill sail
Rock Lb. 1 Avg. Qitnensian (Irt } ; �
14Aan ;100-300 I 12 to 18
0 2 -Man 300-800 18 to 28 Al
i 3 -Man ;800-1500 p 28 to 38
' 4 -Man ;1500-2200 36 to 48 EXPIR S 2 ! $ J^ nY
is 5 -Man 12200-4000 , 48 to 54
2
a
Associated Earth Sciences, Inc.
UNREINFORCED ROCKERY DETAIL FIGURE 2
Associated
DATE 51015
76th AVENUE WEST.
® ® DMONDS WASHINGTON PROJECT No. KED60728A
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