HomeMy WebLinkAboutGEO2014-00005 for BLD2014-00066 - BLD Engineering / Geo-tech Reports - 2/12/2014 20 +14- QED Lo(,o �-"2�I q ..{�p5
PLANNING RECEIVED
Mason County Department of Community Development FEB 12 2014
Submittal Checklist For a Geotechnical Report
426 W. CEDAR$TD
Instructions:
This checklist must be submitted with a Geotechnical Report and completed, signed, and stamped by the
licensed professional(s)who prepared the Geotechnical Report for review by Mason County pursuant to
the Mason County Resource Ordinance. If an item found to be not applicable, the report should explain
the basis for the conclusion.
Applicant/Owner Wilson-Jerome Partnership Parcel#s 32233-44-00020
Site Address
7627 E SR 106 Union, WA 98592
(1) (a)A discussion of general geologic conditions in the vicinity of the proposed development,
Located on page(s) Pages 1-3
(b) A discussion of specific soil types
Located on page(s) Pages 2,3,4&5
(c) A discussion of ground water conditions
Located on page(s) Page 5
(d) A discussion of the upslope geomorphology
Located on page(s) Page 2
(e) A discussion of the location of upland waterbodies and wetlands
Located on page(s) Page 3
(f) A discussion of history of landslide activity in the vicinity, as available in the referenced maps
and records
Located on page(s) Pages 3—4
(2) A site plan which identifies the important development and geologic features.
Located on Map(s) Plan Sheets 1 & 2
(3) Locations and logs of exploratory holes or probes.
Located on Map(s) Plan Sheet 2
(4) The area of the proposed development, the boundaries of the hazard, and associated buffers and
setbacks shall be delineated (top, both sides, and toe) on a geologic map of the site.
Located on Map(s) Plan Sheets 1 &2
(5) A minimum of one cross section at a scale which adequately depicts the subsurface profile, and
which incorporates the details of proposed grade changes.
Located on Map(s) Plan Sheet 3&GALENA Stability Analysis Gages 1 &4
6 A description and results of slope stability analyses performed for both static and seismic loading
( ) P P Y Y
conditions. Analysis should examine worst case failures. The analysis should include the
Simplified Bishop's Method of Circles. The minimum static safety factor is 1.5, the minimum
seismic safety factor is 1.1. and the quasi-static analysis coefficients should be a value of 0.15.
Located on page(s) Page 5 and GALENA Stability Analysis Printout pages 2& 5
(7) (a)Appropriate restrictions on placement of drainage features
Located on page(s) Pages 5-6
(b) Appropriate restrictions on placement of septic drain fields
Located on page(s) Pages 2, 3& 4
(c) Appropriate restrictions on placement of compacted fills and footings
Located on page(s) Page 6& 7
Page 1 of 2 Form Effective June 2008
Disclaimer: Mason County does not certify the quality of the work done in this Geotechnical Report.
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(d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other
slopes on the property.
Located on page(s) Pages 5-6
(e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of
other slopes on the property.
Located on page(s) Pages 5-6
(8) Recommendations for the preparation of a detailed clearing and grading plan which specifically
identifies vegetation to be removed, a schedule for vegetation removal and replanting, and the
method of vegetation removal.
Located on page(s) Page 6
(9) Recommendations for the preparation of a detailed temporary erosion control plan which
identifies the specific mitigating measures to be implemented during construction to protect the
slope from erosion, landslides and harmful construction methods.
Located on page(s) Page 6
(10) An analysis of both on-site and off-site impacts of the proposed development.
Located on page(s) Page 6
(11) Specifications of final development conditions such as, vegetative management, drainage,
erosion control, and buffer widths.
Located on page(s) Page 7
(12) Recommendations for the preparation of structural mitigation or details of other proposed
mitigation.
Located on page(s) Page 7
(13) A site map drawn to scale showing the property boundaries, scale, north arrow, and the location
and nature of existing and proposed development on the site.
Located on Map(s) Plan Sheets 1 &2
I, Alan A.Tahia, P.E. hereby certify under penalty of perjury
that I am a civil engineer licensed in the State of Washington with specialized knowledge of
geotechnical/geological engineering or a geologist or engineering geologist licensed in the State of
Washington with special knowledge of the local conditions. I also certify that the Geotechnical
Report, dated 2-6-14 and entitled Jerome Partnership—Brad Wilson Geotechnical Report
meets all the requirements of the Mason County Resource Ordinance, Landslide Hazard Section, is
complete and true, that the report demonstrates conclusively that the risks posed by the landslide hazard
can be mitigated through the included geotechnical design recommendations, and that all hazards are
mitigated in such a manner as to prevent harm to property and public health and safety. (Signature and
Stamp)
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Page 2 of 2 Form Effective June 2008
Disclaimer: Mason County does not certify the quality of the work done in this Geotechnical Report.
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TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Mason County DCD
Planning Division
PO Box 279
Shelton, WA 98584
Jerome Clark Partnership c/o Brad Wilson
100 East Lilly Pond Lane
Shelton WA. 98584
360-490-2837
Re; Geotechnical Report—Jerome Clark Partnership
Hazard Area Reduction Request
7627 E. SR 106 Union, WA, 98592
Parcel No.: 32233-44-00020
Mason Co. Case No.s: BLD2014-00066
Mason County's geotechnical document review process will determine that the proposed
Jerome Clark Partnership residential property improvements will result in encroachment inside
the 50-foot vegetated Hazard Area Buffer required under Resource Ordinance 17.01.100.
Stability analysis of the slope above the proposed building replacement location indicates that
the structure will satisfy Mason County safety requirements,and the replacement of the garage
&residential structure will not result in any adverse effects.
Therefore, on behalf of the Jerome Clark Partnership I request that a reduction in the Landslide
Hazard Area buffer required in Section 17.01.100 be reduced to as little as a 5-foot dimension
to allow the construction of a replacement residential garage as promoted in my site plans and
geotechnical report dated 2/6/2014.
Sincerely,
W T z
'P �784,;.
�SSIONAL�tyGti
Alan A. Tahja, P.E.
File:C.IProjectslWilson 1410arklHA Buffer Reduction Rqst 1 of 1 2/6/2014
I I
TAHJA ENGINEERING, Inc.
PO Box 235,Hoodsport, WA 98548
(360) 877-9512
Mason County DCD
Planning Division
PO Box 279
Shelton, WA 98584
Brad Wilson
100 East Lilly Pond Lane
Shelton WA. 98584
360-490-2837
Re; Geotechnical Report
7627 E. SR 106 Union,WA, 98592
Parcel No.: 32233-44-00020
Mason Co. Case No.s: BLD2014-00066
INTRODUCTION
I was contacted in Dec 2013 by Mr. Brad Wilson of BRAD WILSON CONSTRUCTION
representing the Jerome Clark Partnership who requested my investigation and documentation of
slope stability and landslide hazard issues relating to the permitting and development of the
Jerome Partnership property located East of Union Washington on the uplands side of SR 106 of
Mason County Washington.
The site was visited in January of this year to collect topographic information and verify
measurements and feature locations. Measurements were made using a Trimble T5415 total
station, a 4-foot range pole, a Sokkia model No. 8047-55 inclinometer, 100 foot and 300 foot
long fiberglass surveyor's tapes and other field equipment common to surveying. Software
employed in creating a site plan and writing this report included AutoCAD 2006, a Terrain 3-d
contour modeling program, GALENA Slope Stability Analysis software, and Microsoft Office
Word 2003. Areal contours were developed from Mason County's GIS website information.
Contours within the property boundaries were developed from topographic survey information
collected for this project.
The site is roughly rectangular in shape running roughly a quarter mile in the north south
direction and roughly 115 feet in its east-west direction. The subject property runs from an
upland elevation of roughly 300 feet sea level to Hood Canal on the north end of the property.
State Highway 106 (SR 106)traverses the property on the north end of the parcel. The proposed
construction is on the portion of the property lying south of SR 106.
The majority of the site is held in a relatively natural condition with second growth conifer and
deciduous trees. The proposed work is the demolition and replacement of an existing basement
garage structure with a main floor living quarter. The structure is located at the toe of the hillside
which contains steep and near vertical slopes climbing over a height of roughly a hundred feet.
These features are shown on the attached site plan.
File:C.kProjectsMlson-JeromelGeo-Rpt 1 of 6 2/6/2014
TAHJA ENGINEERING,Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Under Mason County's Resource Ordinance, land disturbing activities within 300 feet of a
landslide hazard area(slopes>40%with more than 10 feet of height)requires some level of
technical investigation or special report in the form of either a geotechnical assessment, or a
geotechnical report. The slope to the south of the Jerome Partnership property categorizes Mr.
Straight's building plans as being within the County's Critical Resource Ordinance 50-foot
hazard area buffer, so requires the preparation of a geotechnical report based on the owner's
plans, site conditions, and the County's approval of the proposal. The following thirteen
elements are required by Mason County to be addressed in geotechnical reports prepared to
comply with Mason County's Critical Resource Ordinance Sections 17.01.100 through
17.01.104.
1. SURFACE AND GEOLOGIC CONDITIONS:
The site is located East of Union Washington on the upland(south) side of SR 106 in Mason
County Washington in the area identified on the Geologic Map of Shelton 1:100,000
Quadrangle, Washington' on the following page. Hood Canal is located on the Northern end of
the property. The map reveals that the soils surrounding the Jerome Partnership property are
glacial deposits classified as Continental Glacial(Qgt) soils. The soils are further described as
follows:
Till.late Wisconsinan (Pleistocene)—Unsorted,unstratified,highly
compacted mixture of clay, silt, sand,gravel, and boulders deposited
by glacial ice of the Puget lobe; gray;may contain interbedded strati-
fied sand,silt,and gravel; sand-size fraction is very angular and con-
tains abundant polycrystalline quartz,which distinguishes this unit
from alpine till;cobbles and boulders are commonly striated and(or)
faceted; although unweathered almost everywhere, may contain cob-
bles or small boulders of deeply weathered granitic rock.
The building area at the toe of the hillside has been leveled in the past,requiring a very modest
volume of cutting, which steepens at the transition from the Olympic foothill plateau to the Hood
Canal sea level elevation. The hillside slopes are covered with medium aged second growth fir,
hemlock, cedar, and maple trees with a dense understory of Salal, Oregon Grape, and
Huckleberry. The hillside soils are a moderately dense soil to a depth between 2 and 3-feet where
an underlying glacial till layer is present and the soil character becomes strongly cemented.
An access road which leads to the drainfield location traverses the steep slope located south of
the structure location as shown on the attached plans. The upland geomorphology is represented
by the upland plateau south of the property and may be described as hilly.
As the following portion of the Geologic Map of Shelton 1:100,000 Quadrangle reveals, the
Jerome Partnership property is located in the vicinity of at least one fault line identified on the
following map as (1) a fault line which follows Hood Canal is located approximately 3/8 ws of a
mile east of the Jerome Partnership property. The presence of this feature does not represent a
hazard, and standard seismic analysis of the site is intended to anticipate potential tectonic
impacts.
DNR OFR2003-15 Geologic Map of Shelton 1:100,000 Quadrangle, Washington
File:C:IProjectslWilson-✓eromelGeo-Rpt 2 of 6 2/6/2014
TAHJA ENGINEERING, Inc.
PO Box 235,Hoodsport, WA 98548
(360) 877-9512
�ga Qa
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Fault Line Qapo 1 QaPo
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/ Qapo
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Inspection of the Washington Geologic Map shows an area east of the Jerome site as being
shallow& deep disturbances generally in the vicinity of the Olympic Vista neighborhood. The
Olympic Vista instability did not progress in the Jerome Partnership direction and in my opinion,
the hillside behind(south of)the proposed structure replacement location is stable.
No land disturbing activities are planned for any of the steep slopes(>40%) on the property.
2. SITE PLAN WITH IMPORTANT DEVELOPMENT AND GEOLOGIC FEATURES:
A site plan showing the general topography of the area surrounding the Jerome Partnership
property is attached as in appendix. A private well and an Onsite Septic System(OSS)are
generally in the location(s) shown on the attached site plan. No upland water bodies or wetlands
were found in the Jerome Partnership property vicinity,but a seasonal runoff stream courses
northward through the property immediately east of the Jerome Partnership property. This runoff
is accommodated by a highway cross-culvert and pipes which direct the seasonal flow through
the concrete bulkhead located at the north end of the property's waterfront residence.
3. LOCATIONS OF LOGS OF EXPLORATORY HOLES OR PROBES:
Various areas of the Jerome Partnership property were inspected by different methods. The
attached site plan shows the locations of soil probe locations along with the measured depths to a
firm competent substrate layer. The cuts made to construct the access road to the drainfield are
visible at various locations along the length of the access road which further verifies the site's
shallow weathered soil layer located over a more consolidated glacial till layer(s). The probing
showed a moderately dense soil typically 3-feet or less in depth resting on top of a very stiff
cemented glacial till layer. Modeling of the site employed a moderately cemented weathered till
soil layer in the southerly area of the Jerome Partnership property overlying a stronger cemented
till layer beneath the surface soil layer. The northerly portion of the site is modeled as a
homogenous soil of moderately cemented gravelly sand(USCS GP-GC)located above a deep
glacial till layer.
File:C:IProjeetslWilson-JeromelGeo-Rpt 3 of 6 2/6/2014
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
4. AREA OF PROPOSED DEVELOPMENT&BOUNDARIES OF HAZARDS,
BUFFERS,AND SETBACKS:
The attached site plan shows the general locations of existing improvements and planned
replacement construction. The slope(s) south of the Jerome Partnership residence are labeled as
Hazard Areas on the appended site plan. The hazard area's vegetated buffer(50-feet from hazard
areas) is also labeled on the attached site plan.
A building setback from the toe of the southerly ascending slope of 5-feet or more is
recommended to be incorporated into the site's development plans. A request for a reduction of
the hazard area buffer to 5-feet will be prepared for the proposed site development. The existing
structure is located approximately 20-feet north of the toe of the hillside slope and its
replacement is well outside of the recommended buffer distance recommended in this report.
5. CROSS SECTION WITH PROPOSED GRADE CHANGES:
A cross section view of the property is provided in the attached plan sheets as well as a part of
the GALENA Stability Analysis Print-Out.No grade changes are proposed for any of the slopes
on or near the Jerome Partnership property.
6. SLOPE STABILITY ANALYSIS:
The steep slope to the south of the Jerome Partnership property displays no indications of soil
movement or slope instability. The trees on the steep hillside were found to be growing straight
with no indications of trunk curvature typically associated with moving slopes or surface creep
associated with freeze/thaw cycles. Unified Soil Classification System typing places the hillside
soils in a dual symbol category due to its fines content falling between 5 and 12%. The coarse
element of the soil conforms to a GP classification, and the fine soils conform to a GC soil
category. The soils are best described as a GP-GC soils characterized as having a saturated soil
unit weight of 120 lbs/ft, a phi angle of 35°, and a cohesion character of 150 lbs/ft2 for the
weathered surface soils,and a density of 123 lbs/ft3,a cohesion of 300 lbs/ft and a phi angle of
35' for the moderately consolidated glacial till substrate. The water table is located beneath the
till layers underlying the site, and shouldn't affect the stability of the hillside slopes. The site's
stability model used a phreatic surface located above the ground surface to mimic a saturated site
condition.
The slope geometry and soil characteristics provide a factor of safety for the site in a static and a
dynamic analysis that exceeds the County's minimum safety requirements. Analysis of the site
indicates Factors of Safety of LL in a static condition and 1_4 under dynamic conditions for the
hillside south of the Jerome Partnership property.
7. RECOMMENDED SETBACKS & DRAINAGE:
Slope stability analysis indicates that the southerly descending slope south of the Jerome
Partnership property is stable in its present geometry and condition and does not represent a
landslide or geological hazard to the proposed residence construction or neighboring properties.
A 5-foot building setback from the toe of the existing steep slope(s) is recommended for any
permanent structures. The proposed building replacement location provides roughly 20-feet of
separation between the base of the slope and the existing structure.
File:C.kProjectslWilson-JeromelGeo-Rpt 4 of 6 2/6/2014
TAHJA ENGINEERING, Inc.
PO Box 235,Hoodsport, WA 98548
(360) 877-9512
Drainage from the present site is generally dispersed and migrates towards the north,which
should be preserved as the Best Management Practice (BMP) for this site's stormwater runoff.
The site's permeable soils are fairly shallow, generally making infiltration of stormwater runoff
impractical and difficult. Stormwater runoff from the driveway and parking area is collected in a
catch basin located near the middle of the parking area as shown on the attached site plan. A
portion of the roof's runoff is directed to the parking lot catch basin,and a portion of the roof s
runoff is delivered by gutter downspout pipes behind the existing concrete wall/structure back
wall. Water collected from behind the wall in drainage pipes is directed to the westerly side of
the property and directed to the highway ditch by way of a buried drainpipe. The majority of the
site's runoff is accommodated by the existing highway drainage ditch which conveys its flow to
the west, under the highway for discharge to Hood Canal. The existing drainage& surface runoff
east of the property will not be affected by the proposed structure replacement.
8. CLEARING, GRADING, AND VEGETATION MANAGEMENT:
The location of the planned residence replacement was cleared at some past historic date. The
main grading on the site will be excavation of building footings,which should bear on the
undisturbed glacial till layer underlying the building location(s). Mr. Wilson indicated grading
may be performed to replace the fill and drainage behind the existing concrete wall, or that the
existing wall may be replaced and its backfill replaced with a better draining material.
Vegetation should be encouraged to grow on the unimproved areas of the Jerome Partnership
property.
9. EROSION AND SEDIMENT CONTROL:
Inspection of the Soil Survey of Mason County found the site to be located in an area with a
Hoodsport Stoney Sandy Loam(Hg) soil type, which is not identified in the County's Critical
Resource Ordinance as a severe erosion hazard.
The site already has an access to the property off of State Highway 106 and already has an all
weather erosion resistant surface. During construction and grading activities,the parking area
catch basin should be embellished with a piece of filter fabric installed beneath the catch basin's
grate, and a waddle or hay bale barrier should be installed around the catch basin opening.
10. ON-SITE AND OFF-SITE IMPACTS:
Construction and completion of the proposed improvements are not expected to result in any
adverse on-site or off-site impacts.
11. SPECIFICATIONS OF FINAL DEVELOPMENT:
Encouraging vegetation to grow and act as a stormwater mitigation and bank stability element is
recommended for the hillside south of the Jerome property.
12. RECOMMENDATIONS FOR THE PREPARATION OF STRUCTURAL
MITIGATION OR DETAILS OF OTHER PROPOSED MITIGATION:
Modeling of the slope in the proximity of the residence and amenities indicates that the location
of the proposed improvements are and will be safe.No other structural mitigation or details
appear warranted other than placing footings on the un-disturbed glacial till layer underlying the
File:C.IProjectslWilson-JeromelGeo-Rpt 5 of 6 2/6/2014
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
proposed residence location and a 5-foot plus building setback from the toe of the steep southerly
ascending downslope should be maintained.
13. SITE PLAN WITH THE LOCATION OF EXISTING AND PROPOSED
DEVELOPMENT ON THE SITE:
A site plan is attached as an appendix to this report and is hereby made a part of this report along
with the cross section view of the property, and the stability analysis printout.
Summary & Conclusions:
The Jerome Partnership property, though in the vicinity of slopes identified as hazard areas by
Mason County terminology, is stable in its present condition. Development of the site as Mr.
Clark and Wilson are proposing should not result in any adverse impacts to either this or the
neighboring properties.
Please feel free to contact me if there are any questions or concerns regarding this report
or my findings.
Sincerely,
4 aF WA
�p �784 9 ��
IS1 ERA '
�`�SIONAL E�Gl
Alan A. Tahja, P.E.
Attached: Hazard Area Buffer Reduction Request
Plan Views& Cross Section Sheet
GALENATM Stability Analysis Printout
File: C Projects"Wilson-JeromelGeo-Rpt 6 of 6 2/6/2014
Rev# Description Date TAHTA ENGINEERING,INC. SITE PLAN ft i%
Alan Tahja,P.E. Brad Wilson-Jerome Partnership Wilson 14
PO Box 235 100 East Lilly Pond Lane
Hoodsport, WA 98548 Shelton, WA 98584 1 of3
Jefferson Co.hW No.: 32233-44-00020 (360)877-9512 (360)490-2837
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Rev# Description Date TAHJA ENGINEERING,INC. SITE PLAN Wilson 14
Alan Tahja,P.E. Brad Wilson-Jerome Partnership
PO Box 235 100 East Lilly Pond Lane
Hoodsport, WA 98548 Shelton, WA 98584 2 of
Jefferson Co.Prel No.: 32233-44-OW20 (360)877-9512 (360)490-2837
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Alan Tahja,P.E. Brad Wilson-Jerome Partnership Wilson 14
PO
Box 235 100 East Lilly Pond Lane
Hoodsport, WA 98548 Shelton, WA 98584 3 of3
Jefferson Cl 360 Co Pnc No.: 32233-44-00020 ( )877-9512 (360)490-2837
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TAHJA ENGINEERING, Inc.
PO Box 235, HoodspoM WA 98548
(360) 877-9512
Jerome-Wilson X-Section A-A Static Stability Analysis
GALENA v.,*.s.o2
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Analysis: 1
0 Multiple Stability Analysis
Method: Bishop Simplified
Surface: Circular
Results
Cntical(minimum)
-50 Factor of Safety 2.08
0 50 100 150 200 21 300 350 400
Edit"4 Feb MI4 Pooce d 4 Feb M14
Proiect: Jerome
Static
E; C:\Documents and SetWgsVOwrw%My Documents\Galena Fi1es\ModelsUeromeD1.9mf Tahja Engineering,Inc.
Galena 5.02 Analysis Results Licensee: Tahja Engineering, Inc.
DATA: Analysis 1 - Static
Material Properties (2 materials) -------------------
Material: 1 (Mohr-Coulomb Isotropic) - Weathered Surface Soil
Cohesion Phi UnitWeight Ru
150.00 35.0 120.00 1.10
Material: 2 (Mohr-Coulomb Cu increases with depth) - Glacial Till
Cohesion Phi PI UnitWeight Ru
300.00 35.0 0 123.00 1.10
Water Properties----------------
Unit weight of water: 62.40 Unit weight of water/medium above ground: 62.40
Material Profiles (2 profiles) -----------------
Profile: 1 (2 points) Material beneath: 1 - Weathered Surface Soil
0.00 160.00 400.00 160.00
Profile: 2 (9 points) Material beneath: 2 - Glacial Till
0.00 107.00 47.00 87.00 97.03 68.00
115.04 47.00 138.72 38.00
163.83 27.00 199.68 19.00 267.26 17.00
311.52 9.00
Slope Surface (10 points) -------------
0.00 110.00 47.00 90.00 97.03 70.00
115.04 50.00 138.72 40.00
File:C:WrojectsVerome-Wilson X-Sec A-A Analysis Printout 1 of 4 2/06/2014
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
163.83 30.00 171.63 26.00 199. 68 20.00
267.26 18.00 311.52 10.00
Piezometric Surfaces (1 surface) --------------------
Surface within profile: 1 (2 points) - Weathered Surface Soil
0.00 170.00 400.00 170.00
Failure Surface ---------------
Initial circular surface for critical search defined by: XL,XR,R
Intersects: XL: 97.00 YL: 70.01 XR: 200.00 YR: 19. 99
Centre: XC: 158. 90 YC: 66.41 Radius: R: 62.00
Variable Restraints -------------------
Parameter descriptor: XL XR R
Range of variation: 71.00 83.00 35.00
Trial positions within range: 12 12 12
-------------------------------------------------------------------------------------
RESULTS: Analysis 1 - Static
Bishop Simplified Method of Analysis - Circular Failure Surface -------------------
Critical Failure Circle Search using Multiple Circle Generation Techniques
Factor of Safety for initial failure circle approximation: 3. 69
There were: 1022 successful analyses from a total of 1729 trial circles
707 analyses terminated due to unacceptable geometry
Critical (minimum) Factor of Safety: 2.08
Circle and Results Summary (Lowest 15 Factor of Safety circles) -------------------
Circle X-Centre Y-Centre X-Left Y-Left X-Right Y-Right
Radius FoS
1 178. 65 107.36 132.50 42. 63 166.05 28 .86
79.50 2.082
2 147.28 110.83 74.41 79.04 158.50 32.12
79.50 2.178
3 142.24 109. 94 67. 95 81. 62 158.50 32.12
79.50 2.196
4 145.31 107.29 74.41 79.04 158.50 32.12
76.32 2.196
5 143.28 103. 66 74.41 79.04 158.50 32. 12
73.14 2.218
6 140.20 106.21 67. 95 81. 62 158.50 32. 12
76.32 2.225
7 152.29 111.38 80.86 76.46 158.50 32.12
79.50 2.233
8 150.36 108.01 80.86 76.46 158.50 32. 12
76.32 2.233
9 148.39 104.56 80.86 76.46 158.50 32.12
73.14 2.238
10 146.37 101.02 80.86 76.46 158.50 32. 12
69. 95 2.248
11 141.18 99. 90 74.41 79.04 158.50 32.12
69. 95 2.249
12 137.13 108.70 61.50 84.20 158.50 32. 12
79.50 2.252
13 149.01 106.52 74 .41 79.04 166.05 28.86
79.50 2.262
14 138.09 102.35 67. 95 81.62 158.50 32.12
73.14 2.264
15 144 .28 97.36 80.86 76.46 158.50 32.12
66.77 2.271
File: C:IProjectslJerome-Wilson X-Sec A-A Analysis Printout 2 of 4 2/06/2014
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Jerome-Wilson X-Section A-A Dynamic Stability Analysis
GALENA vemo,5 02
200
o�so�
150
100
50
Analysis: 1
0 Multiple Stability Analysis
Method: Bishop Simplified
Surface: Circular
Results
Critical(minimum)
-50 Factor of Safety. 1.44
0 s0 100 150 200 250 300 350 400
E-r 4Feb M1e ProCee r eFWA)1{
Proiect Jerome
Dynamic
&; C:\Documents and Settirlps\OwrwWy Documents\Galena Files\Mode1s\JeromeD1 gmf Tahja Engineering,Inc.
Galena 5.02 Analysis Results Licensee: Tahja Engineering, Inc.
DATA: Analysis 1 - Dynamic
Material Properties (2 materials) -------------------
Material: 1 (Mohr-Coulomb Isotropic) - Weathered Surface Soil
Cohesion Phi UnitWeight Ru
150.00 35.0 120.00 1.10
Material: 2 (Mohr-Coulomb Cu increases with depth) - Glacial Till
Cohesion Phi PI UnitWeight Ru
300.00 35.0 0 123.00 1.10
Water Properties ----
Unit weight of water: 62.40 Unit weight of water/medium above ground: 62.40
Material Profiles (2 profiles) ----------------
Profile: 1 (2 points) Material beneath: 1 - Weathered Surface Soil
0.00 160.00 400.00 160.00
Profile: 2 (9 points) Material beneath: 2 - Glacial Till
0.00 107.00 47.00 87.00 97.03 68. 00
115.04 47.00 138.72 38.00
163.83 27.00 199.68 19.00 267.26 17.00
311.52 9.00
Slope Surface (10 points) -------------
0.00 110.00 47.00 90.00 97.03 70.00
115.04 50.00 138.72 40.00
163.83 30.00 171.63 26.00 199.68 20.00
267.26 18.00 311.52 10.00
File:C.•IProjects Jerome-Wilson X-Sec A-A Analysis Printout 3 of 4 2/06/2014
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Piezometric Surfaces (1 surface) --------------------
Surface within profile: 1 (2 points) - Weathered Surface Soil
0.00 170.00 400.00 170.00
Failure Surface---------------
Initial circular surface for critical search defined by: XL,XR,R
Intersects: XL: 97.00 YL: 70.01 XR: 200.00 YR: 19.99
Centre: XC: 158. 90 YC: 66.41 Radius: R: 62.00
Earthquake Force --- Pseudo-static earthquake (seismic) coefficient: 0. 150
Variable Restraints -------------------
Parameter descriptor: XL XR R
Range of variation: 71.00 83.00 35.00
Trial positions within range: 12 12 12
-----------------------------------------------
RESULTS: Analysis 1 - Dynamic
Bishop Simplified Method of Analysis - Circular Failure Surface
Critical Failure Circle Search using Multiple Circle Generation Techniques
Factor of Safety for initial failure circle approximation: 2. 68
There were: 1022 successful analyses from a total of 1729 trial circles
707 analyses terminated due to unacceptable geometry
Critical (minimum) Factor of Safety: 1.44
Circle and Results Summary (Lowest 99 Factor of Safety circles)
Circle X-Centre Y-Centre X-Left Y-Left X-Right Y-Right
Radius FoS
1 178. 65 107.36 132.50 42.63 166.05 28.86
79.50 1.439
2 162.57 79.63 132.50 42. 63 158.50 32. 12
47. 68 1.595
3 170.31 107.52 126.05 45.35 158.50 32.12
76.32 1. 667
4 147.28 110.83 74 .41 79.04 158.50 32.12
79.50 1. 683
5 142.24 109. 94 67.95 81.62 158.50 32. 12
79.50 1. 692
6 145.31 107.29 74 .41 79.04 158.50 32.12
76.32 1. 697
7 143.28 103. 66 74.41 79.04 158.50 32.12
73. 14 1.715
8 140.20 106.21 67. 95 81. 62 158.50 32.12
76.32 1.716
9 163.81 82.71 132.50 42. 63 158.50 32.12
50.86 1.722
10 150.36 108.01 80.86 76.46 158.50 32. 12
76.32 1.729
11 152.29 111.38 80.86 76.46 158.50 32.12
79.50 1.729
12 137. 13 108.70 61.50 84.20 158.50 32.12
79.50 1.731
13 148.39 104.56 80.86 76.46 158.50 32.12
73.14 1.733
14 149.01 106.52 74 .41 79.04 166.05 28.86
79.50 1.735
File:C:IProjectsVerome-Wilson X-Sec A-A Analysis Printout 4 of 4 2/06/2014
1
Mason County Review Checklist
For a Geotechnical Report
Instructions:
This checklist is intended to assist Staff in the review of a Geotechnical Report. The Geotechnical Report
is reviewed for completeness with respect to the Resource Ordinance. If an item is found to be not
applicable,the Report should explain the basis for the conclusion. The Report is also reviewed for clarity
and consistency. If the drawings, discussion, or recommendations are not understandable, they should be
clarified. If they do not appear internally consistent or consistent with the application or observations on
site, this needs to be corrected or explained. If resolution is not achieved with the author, staff should
refer the case to the Planning Manager or Director.
Applicant's Name: U
Permit# L� a 00 6� Parcel# J Z-�� �`( �QQ
r-{ l /�
Date(s) of fie Document(s) reed: U 2/(q6 r7-fJC
(1) (a)A discrssion of general geologic ccoon�tions in the vicinity of the proposed development,
OK. Comment: r
(b) A discu sion of specific soil types
OK?Comment:
(c) A di�scy-.!�sion of ground water conditions
OK? 1/ Comment:
(d) A discussion of the upslope geomorphology
OK? ✓ Comment:
(e) Adission of the location of upland waterbodies and wetlands
OK? Comment:
(f) A discussion of history of landslide activity in the activity in the vicinity, as available in the
OK?refere ed maps and recor ,_�
Comment: Al�A`GL
(2) A site plan which identifies the i ortant deve pment and geologic features.
OK? Comment: °111Qi�'
(3) Locations pd logs of exploratory hol�pr
OK? ,/ Comment:
(4) The area of the proposed development, the boundaries of the hazard, and associated buffers and
setbacks sh I be delineated (top, both sides, and t on a geologic map of the site.
OK?Comment: �� e� oe( 2—
(5) A minimum of one cross section at a scale which adequately depicts the subsurface profile, and
which incorgerates the details of pro Ud_gr�
de anges.
OK? 1/ Comment:
(6) A description and results of slopes ability analyses performed for both static and seismic loading
conditions.Analysis should examine worst case failures. The analysis should include the
Simplified Bishop's Method of Circles. The minimum static safety factor is 1.5, the minimum
seismic safpty factor is 1.1. and the qu si-static analysis coeffients should be a value of 0.15.
OK? Comment:
(7) (a)Appropri e restrictions on placement of dr age features
OK? Comment: 0�j S- — r
(b) App opr to restrictions on pla e ent of septic drain fields
OK?Comment: � — Lf
(c) Appropri3ie restrictions on placement o co acted fills and footings
OK? Comment:
(d) Recommended buffers from the I n lide hazard areas shoreline bluffs and the tops of other
slopes on the property.
Pagel of 2 Form Effective June 2008
I
6
(e) Recommended setbacks fr m the landslide hazard areas shoreline bluffs and the tops of
other slo s on the property. 6
OK? Comment: ��(
(8) Recommendations for the preparation of a detailed clearing and grading plan which specifically
identifies vegetation to be removed, a schedule for vegetation removal and replanting, and the
method of vegetation removal.
OK? Comment:
(9) Recommendations for the preparation of a detailed temporary erosion control plan which
identifies the specific mitigating measures to be implemented during construction to protect the
slope from osion, landslides and h mfu construction methods.
OK? Comment:
(10) An analysis of both on-site and off-s to pacts of the proposed development.
OK? V Comment: ���
(11) Specifications of final development Andrtions such as, vegetative management, drainage,
erosion control, and buffer widths.
OK',' Comment: G/
(12) Recommendations for the preparatio of structural mitigation or details of other proposed
mitigation.
OK? V Comment:
(13) A site map drawn to scale showing the pr perty boundaries, scale, north arrow, and the location
and nature xisting and pr sed develo�jnt on the site.
OK? Comment:
Are the Documents signed and stamped? .
Type and #of License: I ✓U ` 0 ` A 14 k fa
If not approved, what is the next action/recommendation for further actip
Reviewed by on
Time spent in review:
SECOND REVIEW/UPDATE:
Reviewed by on
Time spent in second review:
THIRD REVIEW/ UPDATE:
Reviewed by on
Time spent in third review:
Disclaimer: Mason County does not certify the quality of the work done in this Geological Assessment
Page 2 of 2 Form Effective June 2008
MASON COUNTY
DEPARTMENT OF COMMUNITY DEVELOPMENT
Planning Division
P O Box 279, Shelton,WA 98584
914 (360)427-9670
Geotechnical ReportReview Acceptance Letter
March 05, 2014
JEROME CLARK
C/O BRAD WILSON
100 E LILLY POND
Case No.: GE02014-00005
Parcel No.: 322334400020
Project Description: REPLACEMENT OF GARAGE WITH LIVING SPACE ON THE 2ND
FLOOR...SEE BLD2014-00066
The Geotechnical Report for JEROME CLARK has been received and reviewed by the Planning
Department. The report was prepared by Alan Tahja dated 2/6/2014.
Based on the certification provided by the licensed engineer/geologist, the referenced
Geotechnical Report was prepared in general accordance with the requirements in the Mason
County Resource Ordinance, Landslide Hazard Areas 17.01.100.E.5. Mason County considers the
review valid until such time as scope of project, site conditions, and/or regulations change. Should
the scope of work, site conditions, and/or regulations change after the original review, then an
addendum from the original author of the report may be required to address these changes. The
report would only be re-reviewed if a permit for development were submitted after these changes
occur. Mason County does not certify the quality of the work done in this Geotechnical Report.
Please contact me at (360) 427-9670, ext. 365 if you have questions.
Sincerely,
//�� 411_�
Allan Borden
Land Use Planner
Mason County Planning Department
Comments:
3/5/2014 Page 1 of 1 GE02014-00005
S EE ED 26 tL4,OW05
RECEIVED
FEB 12 2014
N
426 W. CEDAR S�
S.R. 106
1.5 .5 ,4BA
R PLANNING
_ ---- ��� 7 ,�1gA
_--
existi r i a existing house/garage 7' SHE
footprint
power
O Cr
Well 1120' plot plan for clark jerome partnership
parcel# 32233-44-00020
7627 e. s.r. 106
union wa. 98592
Y) -ro
o i N
12/2/13 Grace spoke with Brad Wilson at counter ab
out 12/2/2013 GBM
reconstruction
ofADU in same footprint. It may be
allowe
d in sam
e footprint with tth Geotechni cal Report.
Suggested he eta p
g approval from Art Sporseen at WSDOT to
reconstruct residence 2'from RW of SR 106.
PLANNING:
ALL SETBACKS ARE MEASURED
FROM THE FURTHEST
PROJECTION OF THE BUILDING
scale 1 " = 30'