CANOD.pdfCity of Edmonds
Critical Area Notice of Decision
Applicant:
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L0114-6
Property Owner:
Critical Area File #-.
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Pen-nit Number;
P> e-6 Zo 130 67
Site Location:()'
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arcel Number:
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Project Description:
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❑ Conditional Waiver. No critical area report is required for the project described above.
1, There will be no alteration of aCritical Area or its required buffer,
I The proposat is an allowed activity pursuant to ECDC 23,40,220, 23.50.220, and/or
23.80,040.
3. The proposal is exempt pursuant to ECDC 23,40,230,
❑ Erosion Hazard. Project is within erosion hazard area, Applicant must prepare an erosion and
sediment control plan in compliance with ECDC 18.30.
.Critical Area Report Required. The proposed project is within a critical area and/or a critical area
buffer and a critical area report is required. A critical area report has been submitted and evaluated
for compliance with the following criteria pursuant to ECDC 23.40.160:
I The proposal minimizes the impact on critical areas in accordance with ECDC 23.40:120,
Mitigation sequencing;
2. The proposal does not pose an unreasonable threat to the public health, safety, or welfare
on or off the development proposal site;
3. i The proposal is consistent with the general purposes of this title and the public interest;
4. Any alterations permitted to the critical area are mitigated in accordance with ECDC
23.40. 110, Mitigation requirements.
5. The proposal protects the critical area functions and values consistent with the best
available science and results in no net loss of critical functions and values; and
6. The proposal is consistent with other applicable regulations and standards.
E] Unfavorable Critical Area Decision. The proposed project is not exempt or does not adequately
mitigate its impacts on critical areas and/or does not comply with the criteria in ECDC 23.40.160 and
the provisions of the City of Edmonds critical area regulations. See attached findings of
noncompliance,
a$+avorable Critical Area Decision. The proposed project as described above and as shown on the
attached site plan meets or is exempt from the criteria in ECDC 23,40 . 160, Review Criteria, and
complies with the applicable provisions of the City of Edmonds critical area regulations. Any
subsequent changes to the proposal shall void this decision pending re -review of the proposal.
❑ Conditions. Critical Area specific condition(s) have been applied to the permit number referenced
above. See referenced permit number for specific condition(s).
141�Q- c6v)
Reviewer
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Date
Appeals: Any decision to approve, condition, or deny a development proposal or other activity based on the
requirements of critical area regulations may be appealed according to, and as part of, the appeal procedure, if any,
for the permit or approval involved.
Revised 12/16/2010
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10406 - 23 1 " Street S W
Edmonds, WA 98020
M
13240 NE 20th Street, Suite 10
BeHevue, Washington 98005
Phone: (425) 649-8757
Group Northwest, Inc.
August 26, 2013
Greg & Rania Carter
10406 - 23151 Street SW
Edmonds, WA 98020
Subject: GE®TEcmicAL REPoRT
Proposed Garage Addition
Greg and Rania Carter Residence
10406 - 2315` Street SW
Edmonds, WA 98020
Geotechnical Engineers, Geologists
& Environmental Scientists
�BS1111
Ref: City of Edmonds, "Plan Review Comments For Plan Check # 2013-0678, Addition At
10406 231St Street SW" dated July 2, 2013.
Dear Mr. and Mrs. Carter:
At your request, GEO Group Northwest, Inc., reviewed the proposed garage addition plans,
conducted a site reconnaissance, explored the site soils and have prepared this geotechnical
engineering report to address the above referenced plan review comments from the City of
Edmonds. This report was prepared pursuant to ECDC 23.40.090 and 23.80.050 addressing
project compliance with the critical area code requirements for development within geologically
hazardous areas. The report also addresses buffer reduction in accordance with.the development
standards in ECDC 23.80.060 and 23.80.070.
A site reconnaissance was conducted on August 7, 2013. The subject lot (Tax Parcel No.
004261-000-008-00) is located at the end of 2315[ Street SW, east of the cul-de-sac at the end of
231" Street SW, as illustrated on the Vicinity Map, Plate 1. Lot access is. from the cul-de-sac by
a private road that ends at the subject lot. The parcel is bordered to the north by Edmonds School
District property and by residentially developed property to the west, east and south.
The lot is approximately 11,696 sf (0.268 acres) in size, and measures approximately 130 feet
along the north property line (includes vacated ROW) and 93.59 feet along the east property line,
as illustrated on the Topographic Survey, Plate 2. The house was constructed in 1973 and is
located in the central portion of the lot with the front of the house facing west. The driveway is
13240 NE 20th Street, Suite 10 Bellevue, Washington 98005
Phone 425/649-8757 Fax 425/649-8758
August 26, 2013
Geotechnical Report
Proposed Garage Addition, Carter Residence
G-3501
Page 2
located on the west side of the house. Roof downspout water is currently dispersed onto the
ground surface. An attached garage is located in the northwestern portion of the structure. The
elevation of the existing garage floor is lower than main floor of the house and is estimated at
approximately Elev. 193.3 feet, based on the surveyed elevations at the garage entrance.
Elevations across the lot range from about Elev. 200 feet at the southeast corner to Elev. 181 feet
at the northwest corner. The east yard of the lot is relatively flat and level. The north end of the
lot slopes gently down to the west, with a grade change of about 4.5 feet across the area of the
proposed addition. The southwestern corner of the lot slopes down from the house to the
driveway with a grade change of about 12 feet.
The school district property to the north is forested and gently slopes to the west in the eastern
portion then slopes down to the west at a gradient of 38 to 51 percent. The property west of the
subject lot slopes down to the west at a gradient of 51 to 64 percent, with the slope gradient
generally increasing towards the south. Two rockery retaining walls are located on the slope
above the neighboring house located southwest of the subject lot. The slope is vegetated with fir
trees, some alder trees and underbrush.
Construction of an addition at the north end of the Carter's house is proposed. The size of the
addition is 16 feet by 39 feet, as illustrated on Garage Addition Plan, Plate 3. The addition will
be two stories. The bottom floor will be a garage and the second floor will have an exercise
room and deck with a hot tub. We understand the finished floor of the bottom`floor garage will
be at the same elevation as the floor of the existing garage. The west wall of the existing garage
is setback 43.3 feet from the west property line at the northwest corner, based on the topographic
survey. The addition will be set back 2 additional feet from the front of the existing garage
(Sheet 3 of the plans), or 45.3 feet from the west property line. The west side of the addition will
be setback about 38 feet from the west edge of the driveway (top of slope). Note: The building
setback from the west property line of 37'-6" shown on Sheet 1 of the Plans (Plate 3) is incorrect
based on the dimensions shown on the survey.
GE® Group Northwest, Inca
August 26, 2013 G-3501
Geotechnical Report Page 3
Proposed Garage Addition, Carter Residence
According to the area geologic maps, the site soil is mapped as Advance Outwash (Qva),
consisting of glacially consolidated pebbly sand deposited by streams issuing from the advancing
ice sheet during the Fraser glaciation period that ended some 12,000 years ago.
According to the Soil Survey of Snohomish County 2, the soils are mapped as Alderwood-Urban
land complex, 2 to g percent slopes, in the upper portion of the project area. The west facing
slope is mapped as Alderwood-Everett gravelly sandy loams, 25 to 70 percent slopes.
The Alderwood-Everett gravelly sandy loam unit is described as being on till plains, terraces, and
outwash plains. It also includes colluvial soils, slump areas, and escarpments. The Alderwood
soil formed in glacial till and is yellow to dark to olive brown very gravelly sandy loam, lies over
weakly cemented hardpan at a depth of about 3 feet, is moderately well drained above the
hardpan, and has a high water erosion potential. The Everett soil formed in glacial outwash sand
and gravel and is very deep, has a high permeability, and has a moderate water erosion potential.
The Alderwood-Urban land complex soil, mapped in the higher portion of area, is mapped on the
glacial till plain. The Alderwood soil is as described above. The Urban land complex soils are
developed areas where the soils are obscured or altered and soil identification was not possible.
Soil Investigation
The subsurface soil conditions were evaluated with two hand auger borings on August 7, 2013.
The boring locations are illustrated on the Topographic Survey, Plate 2. Boring HA -1 was
drilled at the west end of the proposed addition to evaluate the soil bearing conditions and
Minard J. P., 1983, "Geologic Map of the Edmonds East and Part of the Edmonds West
Quadrangles, Washington," U.S. Geological Survey, Miscellaneous Field Studies, Map MF -
1541, Scale 1:24,000.
1953, "Soil Survey of Snohomish County Area Washington," U.S. Department of Agriculture,
Soil Conservation Service.
August 26, 2013
Geotechnical Report
Proposed Garage Addition, Carter Residence
G-3501
Page 4
encountered 10 -inches of crushed rock gravel at the surface, underlain by fine-grained sand with
pebbly gravel and some silt. Soils were dense at a depth of 2 feet, the total depth of the boring.
No groundwater or mottling of the soil was encountered.
Boring HA -2 was drilled between the proposed addition and top of slope to evaluate the soils
above the steep slope area. Fill soil was encountered to a depth of 3.4 feet. The fill appeared to
have been placed to create the driveway when the lot was originally developed. The fill
consisted of loose fine-grained sand with pebbly gravel and some silt. A topsoil layer was
encountered at a depth of 3.4 feet underlain by the fine-grained sand with pebbly gravel and some
silt. Dense soil was encountered at 4.4 feet, the total depth of the boring. No groundwater or
mottling of the soil was encountered.
A cross section soil profile is presented on Plate 4, Cross Section A - A. The sand with pebbly
gravel encountered is consistent with the Advance Outwash soil as mapped on the geologic map
and is consistent with the Everett gravelly sandy loam unit mapped on the soil survey map. For a
more detailed description of the subsurface conditions encountered, please refer to the hand auger
boring logs in Appendix A.
The slope on the neighboring properties to the north and west exceed a gradient of 40 percent and
is classified as a "landslide hazard area." The slope has an estimated height of 50 feet. The top
of the 40 percent slope is located at the west edge of the driveway as illustrated on the
Topographic Survey, Plate 2.
The Advance Outwash (Qva) deposits consist of relatively clean, fine to medium sand with some
pebble gravel that was glacially consolidated by glacial ice. No groundwater or indicators of
groundwater seepage, such as springs, were observed in the borings or on the slope below the
site. The Advance Outwash sand has a moderately high permeability and infiltration rate.
Surface water accumulation and runoff during construction of the addition is not anticipated.
Based on the presence of dense glacially consolidated soil, the site is seismically classified as
111 � ; 11 c
August 26, 2013
Geotechnical Report
Proposed Garage Addition, Carter Residence
G-3501
Page 5
Site Class C (very dense soil), in accordance with Table 1613.5.2 of the 2006 International
Building Code (IBC). The potential for liquefaction, lateral spreading, or a deep seated slide to
occur as a result of a large magnitude seismic event, is negligible. No known faults intersect the
subject property and the risk of surface rupture, as a result of a large magnitude seismic event, is
very low. No geotechnical seismic mitigation measures are recommended.
The slope on the property below and north of the subject lot appears to be an undisturbed, natural
slope. We did not observe evidence of past landslides or slope instability on the subject lot or on
the adjacent slope. The trunks of the trees on the slope are generally straight and we did not
observe signs of slope instability such as slumps, slides, scarps, or tension cracks, or water
seepage emanating from the slope. The slope appears to be stable, based on the geology and the
site condition observations.
The driveway fill was likely placed when the house was constructed in 1973. The fill is loose,
consisting of reworked Advance Outwash sand and gravel based on the soils encountered in
Boring HA -2 at the north end of the driveway. We estimate the fill thickness to be about 6 feet
along the west side of the driveway, decreasing in thickness up-slope to the east. The surface of
the driveway slopes down to the west and southwest and the surface has a slight concave
appearance. A small settlement crack was observed in the asphalt in the middle of the driveway
in front of the garage. The driveway appears to have settled several inches since it's
construction. No downslope movement of the driveway fill was observed. The driveway fill has
been in place some 40 years and appears to be stable.
There is minimal risk for a deep seated slide to occur due the presence of dense glacially
consolidated Advance Outwash soil. Construction of the proposed addition will not decrease the
factor of safety for a landslide occurrence beyond the current condition. There is a minor risk for
shallow sloughing or slumping to occur in the loose driveway fill. This is due to the loose nature
of the fill soil. The driveway fill appears stable and no site work, grading or vegetation removal
is proposed in that area. It is our opinion the risk is low for sloughing or slumping to occur,
based on the site conditions and past performance of the driveway fill. This risk will not be
increased as a result of the construction of the proposed addition.
+,1 ib, � '
August 26, 2013 G-3501
Geotechnical Report Page 6
Proposed Garage Addition, Carter Residence
Lazard Analysis
The top of the steep slope is located at the west edge of driveway. The west end of the garage
addition will be set back approximately 38 feet from the top of the slope. The addition will not
be located within the area of the driveway fill soil, based on the soil encountered in boring HA -1.
The area of the proposed garage addition principally consists of gravel surfacing and ornamental
plants. Based on the site conditions and presence of dense glacially consolidated Advance
Outwash soil, it is our opinion the addition will not negatively impact the stability of the steep
slope area, during construction or post construction, including the subject property and adjoining
properties.
Based on the findings of this geotechnical site evaluation, the garage addition, as proposed, will
not negatively impact site stability and will not increase erosion. We recommend a reduction of
the buffer to 10 feet from the top of the slope and a building setback of 20 feet from the buffer,
thus allowing. construction of the proposed addition.
Based on the results of this geotechnical evaluation, the recommended buffer reduction will not
increase the threat of the geologic hazard to adjacent properties beyond predevelopment
conditions; will not adversely impact the steep slope critical area; is designed so that hazard to
the project is eliminated or mitigated to a level equal to or less than predevelopment conditions;
and is certified as safe as designed and under the anticipated conditions by the geotechnical
engineer and engineering geologist.
Mitigation recommendations consist of the following:
1. Installation of erosion control measures prior to the start of earthwork.
2. Deepening of the west foundation wall footing of the addition.
Details regarding the above mitigation recommendations are discussed in the following sections.
August 26, 2013 G-3501
Geotechnical Report Page 7
Proposed Garage Addition, Carter Residence
Temporary erosion control measures should be installed prior to the start of grading, such as
perimeter silt fencing installed down -gradient of the work area. If the existing gravel surface is
not adequate to mitigate tracking of mud onto the street, a crushed rock construction entrance
should be installed. During wet weather, exposed soil should be covered with straw mulch and
cut slopes protected with plastic sheeting to mitigate erosion. Minimal surface water runoff is
anticipated due to the sandy nature of the site soils, however crushed rock check dams, hay bales,
and silt fencing should be used, as needed, to reduce suspended sediment and reduce the velocity
of the runoff.
Temporary cut slopes for the foundation excavation should not exceed 1H:1V in the loose sandy
soil. We anticipate a maximum cut of about 6 feet at the northeast comer of the addition. We
anticipate the base of the perimeter footing will be approximately Elev. 191.8 feet (about 1.5 feet
below the finished floor elevation of the addition), except across the west side where we are
recommending the footing be deepened. The addition will be setback about 8 feet from the north
property line, so there appears to be adequate space for the temporary cut without encroaching
into the neighboring property.
Minimal regrading is anticipated around the addition for the final site grades. `In general,
permanent cut or fill slopes should be inclined no steeper than 2H: IV. Permanent fill slopes
should be compacted to a minimum of 90 percent of the material's maximum dry density and be
constructed with a granular material. Permanent slopes of 3H: IV, or less, are recommended if
the slope is to be mowed and maintauied.
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Soils supporting the building foundation, slab -on -grade floor, retaining walls, and driveway
should be grubbed and stripped of topsoil and soils containing wood and organic debris. Soils
supporting the addition should be dense and non -yielding. If loose soils are present we
recommend the subgrade be evaluated by the geotechnical engineer. Compaction of the
subgrade, or removal of the loose soil and replacement with compacted structural fill may be
August 26, 2013
Geotechnical Report
Proposed Garage Addition, Carter Residence
required.
STRUCTURAL FILL
G-3501
Page S
Structural fill is defined as compacted engineered fill soil used to support building foundation
loads, floor slabs, patios, porches, retaining walls, sidewalks, and pavements. During dry
weather, any non-organic granular soil may be used as structural fill, provided the material is
near the optimum moisture content for compaction purposes and the material achieves the
compaction specifications when compacted. The sandy site soil should be a suitable material for
use as structural fill. During wet weather we recommend a sand and gravel material with the
following specifications in order for the material to achieve the compaction specification:
1. Free draining, granular material, which contains no more than 5 percent fines (silt and
clay -size particles passing the No. 200 mesh sieve);
2. Free of organic and other deleterious substances;
3. Maximum size of three -inches.
Structural fill material should be placed and compacted at or near the material's optimum
moisture content. The optimum moisture content is the water content in soil that enables the soil
to be compacted to the highest dry density for a given compaction effort. If feasible, the site
grading and earthwork should be performed during the dry summer months. Soils containing
organics, debris and/or rubble should not be used as structural fill.
STRUCTURAL;u OOSPECIFICATIOILIS
Structural fill should be placed at or near the material's optimum moisture content and be
compacted in 10 -inch thick lifts, or less. Structural fill supporting building foundations, slab -on -
grade floors and other structural elemnts, should be compacted to a minimum of 95 percent of
the material's maximum dry density, as determined by ASTM Test Designation D-1557
(Modified Proctor). Fill adjacent to foundations should be compacted to 90 percent (95 percent
if supporting slabs, patios, porches, CMU retaining walls, or other structural elements).
Structural fill supporting driveways and sidewalks should be compacted to 90 percent, with the
exception of the top 12 -inches which should be compacted to 95 percent. Structural fill within
the street right-of-way should be compacted to the city/county specifications. The Utility District
may require 95 percent compaction for trench backfill below pavements. Structural fill in utility
trenches should be compacted to the utility district or city/county specifications.
August 26, 2013 G-3501
Geotechnical Deport Page 9
Proposed Garage Addition, Carter Residence
Foundations may be supported on conventional spread strip and column footings. We
recommend the west (down -gradient) foundation footing be deepened to a minimum of 30 -inches
below the finished floor elevation. Footings may be supported directly on dense soil or on
structural fill that extends down to dense soil. A representative from GEO Group Northwest
should verify that the soil bearing conditions are suitable for foundation support. Fill supporting
foundations should be compacted to 95 percent of the material's maximum dry density.
Structural fill below footings should create a prism that extends out and below the footing at
1H:2V, so for 2 feet of over -excavation the structural fill should extend out beyond the footprint
by a minimum of 1 foot. The following building foundation design criteria is applicable to
spread footings supported as described above:
® Allowable bearing pressure, including all dead and live loads:
Supported by structural fill soil or dense undisturbed soil: = 2,500 psf
® Minimum depth to bottom of perimeter footing below
final exterior grade: = 18 inches
® Minimum depth to bottom of perimeter footing below
final exterior grade for the west foundation footing: = 30 inches
® Minimum depth to bottom of interior footings
below top of floor slab: = 12 inches
® Minimum width of strip footings: = 16 inches
® Minimum lateral dimension of column footings: = 24 inches
® Estimated post -construction settlement: = 1/4 inch
— Across building width: = 1/4 inch
A one-third increase in the above allowable bearing pressures can be used when considering
short-term transitory wind or seismic loads. Lateral loads can also be resisted by friction
between the foundation and the supporting compacted fill subgrade or by passive earth pressure
acting on the buried portions of the foundations. For the latter, the foundations must be poured
"neat" against the existing undisturbed soil or backfilled with a compacted fill meeting the
GEO Group Northwest, Inco
August 26, 2013 G-3501
Geotechnical Report Page 10
Proposed Garage Addition, Carter Residence
requirements of structural fill. Our recommended parameters are as follows:
- Passive Pressure (Lateral Resistance)
® 350 pcf equivalent fluid weight for dense site soils and structural fill
- Coefficient of Friction (Friction Factor)
® 0.35 for dense site soil and structural fill
The existing garage floor steps up about 16 -inches to the game room located on the east side of
the garage. The foundation footing of the north wall of the existing structure may also step up in
this area. If it steps up and it is higher than the finished floor elevation of the addition, then the
existing house foundation footing will need to be extended deeper. The above geotechnical
design parameters may be used for the deepened foundation footing, however we recommend the
geotechnical engineer review the condition and provide recommendations to avoid
compromising the existing foundation support.
Subgrade support for the slab -on -grade floor should be prepared so the floor slab is supported on
dense soil or supported on structural fill compacted to 95 percent of the material's maximum dry
density, in accordance with the specifications for structural fill.
Slab -on -grade floors should be placed on a capillary break to prevent wicking of moisture
through the slab. The capillary break should consist of a minimum of six (6) inch thick free -
draining layer of 1.5 inch minus gravel containing no more than five (5) percent fines passing the
No. 4 (1/4 -inch) sieve. To reduce wafer vapor transmission through the slab we recommend
installing a 10 -mil reinforced vapor barrier, such as Moistop® by Fortifiber Corporation, between
the capillary break and concrete floor slab. Two to four inches of sand may be placed over the
membrane for protection during construction (optional).
GE® Group Northwest, Inc.
August 26, 2013
Geotechnical Report
Proposed Garage Addition, Carter Residence
i I I) y I TIT
G-3501
Page 11
The below grade portion of the foundation walls should be waterproofed and a perimeter footing
drain installed, as illustrated on the Footing Drain Detail, Plate 5. The foundation walls should
be backfilled with a clean free -draining granular soil. The onsite sandy soil should be usable for
this purpose. The footing drain should consist of a four (4) inch minimum diameter, perforated,
rigid drain pipe laid at or near the bottom of the footing with a gradient sufficient to generate
flow. The drain line should be bedded in washed drain rock and the drain rock protected from
clogging with geotextile filter fabric, such as Mirafi 140N, or equivalent, wrapped around the
drain rock. The footing drain should outlet to the storm drain or an appropriate discharge
location. The footing drain will not generate much water due to the sandy soil conditions. If a
storm drain system is not available, discharge to the bed at the end of the driveway is acceptable
in our opinion.
Roof, yard, and other drain lines should not be connected to the footing drain system. The
footing drain should be separately tight -lined to the outfall point. We recommend that sufficient
clean -outs be installed to allow for periodic maintenance of both the footing drains and roof
down -spout tight -line systems.
Roof downspout water from the existing house discharges onto the ground surface and infiltrates
into the ground or is directed to the asphalt driveway. Driveway surface water appears to flow
south, down the driveway. No areas of erosion or concentrated surface water discharge onto the
slope below the driveway was observed. Concentrated water should not be discharged directly
on the slope. The existing roof water discharge system appears to function without being
detrimental to the stability of the slope.
The addition plans call for roof downspouts to discharge to splash blocks on the ground surface.
It is our opinion that discharge to splash blocks is acceptable, provided a stormwater drainage
system is not available. If a stormwater drainage system is available, we recommend the roof
downspout water be tight -lined to the storm drain.
August 26, 2013 G-3501
Geotechnical Report Page 12
Proposed Garage Addition, Carter Residence
It is recommended that GEO Group Northwest provide geotechnical monitoring/inspection
services to confirm that the subsurface conditions are consistent with those described in this
report and allow design changes in the event subsurface conditions differ from those anticipated
prior to the start of construction. It will also allow us to evaluate whether the geotechnical
aspects of the construction activities conform to the contract plans, specifications, and
geotechnical recommendations.
While on the site during construction, we will not direct or supervise the contractor or the
contractor's work, nor will we be responsible for providing or reviewing on-site safety or
dimensional measurements. We request that the contractor provide a minimum of 24 hours
advance notice to perform inspections so that we can arrange to have personnel available.
II i►i� 1 ll'W.7��►fy
This report has been prepared for the specific application to the subject project. The findings and
recommendations stated herein are based on our field observations, the subsurface conditions
encountered in our site exploration, our experience, and judgement. The recommendations are
our professional opinion derived in a manner consistent with the level of care and skill ordinarily
exercised by other members of the profession currently practicing under similar conditions in this
area and within the budget constraint. No warranty is expressed or implied. In the event that soil
conditions vary during site work, GEo Group Northwest, Inc., should be notified and the
recommendations herein re-evaluated, and where necessary, be revised.
August 26, 2013
Geotechnical Report
Proposed Garage Addition, Carter Residence
Please contact us if you have any questions regarding this report.
Sincerely,
GE® GROUP NORTHWEST, INC.
Wade J. Lassey
Engineering Geologist
William Chang, P.E.
Principal
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Attachments:
Plate 1 - Vicinity Map
Plate 2 - Topographic Survey
Plate 3 - Garage Addition Plan
Plate 4 - Cross Section A - A'
Plate 5 - Footing Drain Detail
Appendix A - USCS Soil Classification Legend and Boring Logs
GE® Group Northwest, Inca
G-3501
Page 13
Adapted from "The Thomas Guide," 2007.
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VICINITY MAP
®Grou Northwest, Inc.
PROPOSED ®s GARAGE ADDITION
Geotechnical Engineers, Geologists, & 10405 - 231st STREET SW
Environmental Scientists
EDM® S, WASHINGTON
SCALE As Shown DATE 8/26/2013 1 MADE WJI CHKD WC JOE NO. G-3501 ELAS 1
(MIYOVA)
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Approx. Scale: 1 inch = 30 feet
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Adapted from the Site Plan on Sheet I of the plans titled, The Carter Residence "Garage Addition", dated 6/9/13, by Keith Beddow, CBD.
MWG—rSITE PLAN
®up Northwest, Inc. PROPOSED GARAGE ADDITION
Geotechnical Engineers, Geologists, 8 10406 - 23151[ STREET SW
® Environmental Scientists
EDM® S, WASBINGTON
SCALE As Shown I DATE 8/20/13 1 MADE WJL CHKD WC I JOB NO. G-3501 I PLATE 3
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WALL
WATER -PROOFING F\
0
SLOPE TO DRAIN ® .
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0 0 0
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GEOTEXTILE
.. Structural Fill
FILTER FABRIC
..:;:;: FOOTING a . :� Compacted to 95%
(Mirafi 140 N, or equivalent)
I II�II��II
FOOTING DRAIN
WASHED GRAVEL
Minimum 4 -inch diameter rigid slotted or
perforated PVC pipe with positive gradient
to discharge.
�1711�E1C�TY�7:f
NOTES:
1.) Do not replace rigid PVC pipe with flexiible corrugated plastic pipe.
2.) Perforated or slotted PVC pipe should be tight jointed and laid with
perforations or slots down, with positive gradient to discharge.
3.) Do not connect roof downspout or other drains into the footing drain system.
� � � t;,
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LEGEND CLASSIFICATION % D PENETRATION TEST
UNIFIED SOIL CLASSIFICATION SYSTEM (USCS)
MAJOR DIVISION
GROUP
DESCRIPTION
LABORATORY CLJASSIFICAT10N CRITERIA
SYMBOLTYPICAL.
WELL GRADED GRAVELS, GRAVEL -SAND
Cu = (080 / D10) g than 4
CLEAN
GW
MIXTURE, LITTLE OR NO FINES
DETERMINE
Cc = (1331y) / (D10' D8 n 1 and 3
GRAVELS
PERCENTAGES OF
GRAVELS
(little or no
GP
POORLY GRADED GRAVELS, AND GRAVEL -SAND
GRAVEL AND SAND
NOT MEETING ABOVE REQUIREMENTS
(More Than Hak
fines)
MIXTURES LITTLE OR NO FINES
FROM GRAIN SIZE
COARSE-
Grains
DISTRIBUTION
ATTERBERG LIMITS BELOW
GRAINER SOILSCoarse
Larger Than No. 4
CURVE
Ste)
DIRTY
GM
SILTY GRAVELS, GRAVEL -SAND -SILT MIXTURES
"A7 LINE
CONTENT
or P.I.GRAVELS LESS THAN 4
OF FINES
CLAYEY GRAVELS, GRAVEL -SAND -CLAY
ATTERBERG LIMITS ABOVE
( same
EXCEEDS 12%
Ones)
GC
MIXTURES
COARSE GRAINED
SOILS ARE
or P.I. MORE THAN 7
CLASSIFIED
WELL GRADED SANDS, GRAVELLY SANDS,
FOLLOWS::
Cu = (1380 / Dt 0) greater than 8
SANDS
CLEAN
SW
LITTLE OR NO FINES
Cc = (DW) / (D10. 680) between 1 and 3
SANDS
(More Than Hak
Coarse Grains
(Iiftle a
SP
POORLY GRADED SANDS, GRAVELLY SANDS,
< 5% FineGP, Grained:
Grained -
NOT MEETING ABOVE REQUIREMENTS
More Than Hak
SmaJW Than No.
fin)
LITTLE OR NO FINES
GW, GP, SW, SP
WeightLaW
Than No 200
4 Slave)
ATTERBERG LIMITS BELOW
S1em
DIRTY
SM
SILTY SANDS, SAND -SILT MIXTURES
> 12% Fine Grained:
"A"UNE
SANDS
GM, GC, SM, SC
CONTENT OF
withFINEwithP.1. LESS THAN 4
5 to 12% Fine
EXCEEDS12%
ATTERBERG LIMITS ABOVE
(with some
SC
CLAYEY SANDS, SAND -CLAY MIXTURES
Grained: use dual
"A' LINE
Ones)
symbols
with P.I. MORE THAN 7
SILTS
Liquid Umk
INORGANIC SILTS, ROCK FLOUR, SANDY SILTS
(Below A -Una on
c 50%
ML
OF SLIGHT PLASTICITY
so -
Plasticity Chart,
PLASTICITY CHART
/
A -Line
Liquid Limit
INORGANIC SILTS, MICACEOUS OR
FINE-GRAINED
Negligible
50
FOR SOIL PASSING
I
CH or OH
SOILS
Organic)
> 5
MH
DIATOMACEOUS, FINE SANDY OR SILTY SOIL
_
NO. 40 SIEVE
INORGANIC CLAYS OF LOW PLASTICITY,
CLAYS
Liquid Umk
U%
CL
GRAVELLY, SAND SILTY CLAYS, CLEAN
640
(Above AYS an
<id
COR
Plasticity Chart
Negligible
Liquid Limit
INORGANIC CLAYS OF HIGH PLASTICITY, FAT
Organic)
> 50%
CH
CLAYS
U
CL or OL
More Than Hak by
h
2(3"MH
Weight Larger
Liquid Limit
ORGANIC SILTS AND ORGANIC SILTY CLAYS OF
or OH
Than No. 200
ORGANIC SILTS S
< 50%
OL
LOW PLASTICITY
Sieve
CLAYS
10
or
(Below A -Line on
7
Plasticity Cham
Liquid Limit
OH
ORGANIC CLAYS OF HIGH PLASTICITY
4
OL r M
v
0__
10 20 30 40 50 80 70 80 90 100
110
HIGHLY
ORGANIC SOILS
Pt
PEAT AND OTHER HIGHLY ORGANIC SOILS
LIQUID LMT(°pa)
SOIL. PARTICLE SIZE
GENERAL GUIDA14CE OF SOIL ENGINEERING
PROPERTIES FROM STAN TION TEST'(S�
U.S. STAND SIEVE
FRACTION
Passing
Retained
SANDY SOILS .
SILTY A CLAYEY SOILS
Sieve
size
Sieve
Size
Blow
Relative
Friction
Blow
Unconfined
(MM)
(MM)
Counts
N
Density
%
Angle
dogma
Description
Counts
N
Strength
qu, tet
Description
SILT / CLAY
#2013
0.075
SAND
0.4
0.15
Very Loose
<2
< 0.25
Very soft
FINE
#40
0.425
#200
0.075
4.10
15-35
28-30
Loose
2-4
0.25-0.50
Soft
MEDIUM
010
200
#40
0.425
10-30
35-65
28-35
Medium Dense
4-8
0.50 -1.00
Medium Stili
COARSE
#4
4.75
#10
200
30-50
> 50
85 - 85
85-100
35-42
38-40
Dense
Very Dense
8-15
15-30
1.00-2.00
200-4.00
Stift
Very Stiff
GRAVEL
FINE
19
04
4.75
> 30
> 4.00
Hard
COARSE
78
19
COBBLES
78 mm to 203 mm
Group Northwest, Inc.
(W
13OUL.DERS
> 203 mm
Geotechnical Engineers, Geologists, S
Ersvlmnmental Scientists
ROCK
—
FRAGNBITS
> 78 mm
13240 NE 20th Street Suite 12 Bellevue, WA 98005
Phone (425) 848.8757 Fax (425) 849-8758
PLATE Al
ROCK
>0.78 cubit motor in velum®
HAND AUGER BORING NO. HA -1
LOGGED BY WJL EXCAVAT10N DATE 8n1l3 GROUND ELEV. 194.5 feet
DEPTH
ft.
USCS
SOIL DESCRIPTION
SAMPLES
COMMENTS
SM
Crushed Rock Gravel, with dark brown sandy soil mix
® _
Sm
(FALL)
(FILL)
- Probed< I" at 9"
— —
— — — — — — --- — — — — — — — — —
S1
Probed to 4'bgs at 18"
SP_
SAND, light brown, fine gained with subrounded pebble
Sl
- Probed 6" at 14"
SM
gravel and some silt, medium dense to dense, damp,
2
---
® —
(Advance Outwash)
S2
.
-
Top Soil Layer at 3.4'
S2
-probed < I" at 24"
Sp-
ed
SAND, light brown, fine grained with subrounded
S3
_
pebble gravel and some silt, loose to medium dense
Total Depth = 2 feet (Gravel Refusal)
(dense at 4.4'), damp (Advance Outwash)
No Groudwater Seepage
Approx. Boring Location: I FN & 4'E of
4 _
Total Depth = 4.4 feet (Gravel Refusal)
SW Comer of Existing Garage
HAND AUGER BORING NO. HA -2
LOGGED BY WJL EXCAVATION DATE 8n1l3 GROUND ELEV. 190.5 feet
DEPTH
ft.
USCS
SOIL DESCRIPTION
Samples
COMMENTS
SM
Silty SAND with organics, dark brown (FILL)
® _
Sm
® ® ® ® ® — ® — — — ® ® ® ® ® — — —
SAND with silt, gray -brown, some gravel, loose, damp
(FILL)
S1
Probed to 4'bgs at 18"
SP-
SAND, brown, fine grained with subrounded pebble gravel
SM
and some silt, loose, damp (FILL)
---
® —
— — ®®o®®®®®®®®®® — —
S2
Probed to 14" at 40"
Top Soil Layer at 3.4'
Sp-
ed
SAND, light brown, fine grained with subrounded
S3
SM
pebble gravel and some silt, loose to medium dense
Probed 0" at 4.4' (Dense)
(dense at 4.4'), damp (Advance Outwash)
Total Depth = 4.4 feet (Gravel Refusal)
No Groundwater Seepage
Approx. Boring Location: 14'N & 23'W of
SW Comer of Existing Garage
OWGroup Northwest, Inc.
Geotechnical Engineers, Geologists, &
Environmental scientists