HomeMy WebLinkAboutGEO2011-00075 for BLD2011-00671 - GEO Geological Review - 10/11/2011 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: 4q/�5
Permit#: J-k�//—�7/ Parcel 3;)33/ 2, QOC�00
Date(s) of the Document(s) reviewed:
1. (a) A discussion of general geologic conditions in the vicinity of the proposed development,
OK? Comment:
(b) A discussion of specific soil types
OK? LI-1 Comment:
(c) A discussion of ground water conditions
OK? l/ Comment:
(d) A discussion of the upslope geomorphology
OK? y Comment:
(e) A discusstg of the location of upland waterbodies and wetlands
OK? Comment:
(f) A discussion of history of landslide activity in the vicinity, as available in the referenced maps and records
OK? 6/ Comment:
2. A site plan that identifies the important development and geologic features.
OK? Comment:
3. Locations and logs of exploratory holes or probes.
OK? Comment:
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.
OK?Z-'-_Comment:
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.
OK? Comment:
6. A description and results of slope stability 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 safety factor is 1.1 and the quasi-static
analysis coeffients should be a value of 0.15.
OK? lam. Comment:
7. (a) Appropriate r strictions on placement of drainage features
OK? Comment:
(b) Appropriate restrictions on placement of septic drain fields
OK? i/ Comment: gIrAW4 in
(c) Appropriate restrictions on placement of compacted fills and footings.
OK? V Comment: 41'144
Page 1 of 2 Form Effective June 2008
(d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other slopes.
OK? ✓ Comment: jcU
(e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of other slopes.
OK? l,/ Comment: lC�
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 erosion, landslides and
harmful construction methods.
OK? ✓ Comment: IV--—
10. An analysis of both on-site and off-site impacts of the proposed development.
OK? — Comment:
11. Specifications of final development conditions such as, vegetative management, drainage, erosion control, and
buffer widths.
OK? ✓ Comment: ion
12. Recommendations for the preparation of structural mitigation or details of other proposed mitigation.
OK? Comment: ndhc-
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.
OK? '� Comment:
Are the Documents signed and stamped? By whom?
License#: Li ense type: r �-✓�
FIRST REVIEW Approved ❑ Need more info.
If not approved, what is the next action/recommendation for further action?
Reviewed by on Time spent in review:
SECOND REVIEW/UPDATE ❑ Approved ❑ Need more info.
Reviewed by , on . Time spent in second review:
THIRD REVIEW/UPDATE ❑ Approved ❑ Need more info.
Reviewed by , on . Time spent in third review:
Disclaimer: Mason County does not certify the quality of the work done in this Geotechnica/Report.
Page 2 of 2 Form Effective June 2008
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Gie-0 2-06
OCT
j. t ;i I
� 0 85
V6 Mason County Department of Community Development
Submittal Checklist For a Geotechnical Report
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 Leonard "Brook" Lawless Parcel# 32331-22-00000
Site Address 350 N Arnold's Way, Hoodsport, WA 98548
(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 activity in the vicinity, as available in the
referenced maps and records
Located on page(s) Pages 2-3 .
(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 pages 1 &3
(6) A description and results of slope stability 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 safety factor is 1.1. and the quasi-static analysis coefficients should be a value of 0.15.
Located on page(s) Pages 4-5,&GALENA Stability Analysis Printout pages 2& 4.
(7) (a)Appropriate restrictions on placement of drainage features
Located on page(s) Page 5
(b) Appropriate restrictions on placement of septic drain fields
Located on page(s) Page 3
(c) Appropriate restrictions on placement of compacted fills and footings
Located on page(s) Pages 5& 6.
Page 1 of 2 Form Effective June 2008
Disclaimer: Mason County does not certify the quality of the work done in this Geotechnical Report.
(d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other
slopes on the property.
Located on page(s) Page 5
(e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of
other slopes on the property.
Located on page(s) Page 5
(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 5
(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) Pages 5-6
(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 6
(12) Recommendations for the preparation of structural mitigation or details of other proposed
mitigation.
Located on page(s) Page 6
(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
Reports, dated 10/10/2011 , and entitled Lawless Geotechnical Report meets all the requirements of
the Mason County Resource Ordinance, Landslide Hazard Section, are complete and true, that the
reports 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.
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Mason County DCD
Planning Division
PO Box 279
Shelton, WA 98584
Leonard "Brook" Lawless
PO Box 484
Hoodsport, WA 98548
(360) 877-9072
Re; Geotechnical Report
350 N Arnold's Way
Hoodsport, WA 98548
Parcel No.: 32331-22-00000
Mason Co. Case No.s;
INTRODUCTION
I was contacted in September of this year by Mr. Leonard "Brook" Lawless who requested
my investigation and reporting of the above referenced property for the permitting of a
carport shelter or shop on his Restawhile area property located approximately 2`/2 miles north
of Hoodsport. The property is located at the end of Arnold's Way which is accessed by way
of Terrace Road and Westward Way, private roads in the White Star community.
The site has been visited numerous times to collect topographic information needed to
prepare this report and develop drawings to assist in placing the structure in compliance with
regulatory requirements.
Measurements were made using 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 AutoCADTM 2006,
a SoftreeTm Terrain 3-d contour modeling program, GALENA TM Slope Stability Analysis
software and MicrosoftTM Office Word 2003.
The proposed structure location is on a natural 19% descending slope as shown on the
attached site plans. Other areas of the Lawless property contain slopes ranging from 40 to
50% over elevation differences of 20 to 50 vertical feet as shown on the attached site plans.
With slopes on or within 300 feet of the property exceeding 40% with a height of 10 feet or
more, Mason County requires a geotechnical report to be developed to address stability
issues relating to the property's development. 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 (MCRO) Sections 17.01.100 through 17.01.104.
File: C:TrojectslLawlesslGeo-Rpl 1 of 6 10/11/2011
i
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
1. SURFACE AND GEOLOGIC CONDITIONS:
The property has been logged in the distant past and currently is covered with a fairly even
aged stand of second growth timber, mainly Fir, Hemlock, Cedar and Alder trees. Most of
the property is covered with native underbrush consisting of Salal, Oregon Grape,
Huckleberries and Blackberries. The trees located on the property's steep slope and on
adjacent properties are growing straight with no indication of ground motion, sliding or
slippage.
Inspection of the Geologic Map of Shelton 1:100,000 Quadrangle, Washington', finds the
property located in an area between the Olympic Mountain foothills to the west and Hood
Canal to the east. The upland geomorphology of the area surrounding the Lawless property
can be typified as steep and mountainous. A portion of the Shelton Quadrangle map reveals
the site soils are classified as Qgt, Continental Glacial Deposits—Fraser Glaciation-Vashon
Stade, and are further described as follows:
Q9t 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.
As a portion of the Geologic Map of Shelton 1:100,000 Quadrangle on the following page
reveals, the Lawless property is located in the vicinity of several fault lines identified on the
following map as (1) the terminus of two faults emanating from the north and terminating
approximately 2.5 miles to the northwest of the Lawless property on the north side of Dow
Mountain(2) a fault line runs southwest to northeast through Lake Cushman approximately
5.5 mile northwest of the Lawless site, and(3) a fault line which follows Hood Canal is
located approximately 1.5 miles east of the Lawless site. The presence of these features does
not represent a hazard, and standard seismic analysis of the site is intended to anticipate
potential tectonic impacts.
Investigation of Washington State's Dept. of Ecology's Coastal Atlas found the Lawless
property vicinity identified as unstable. The Lawless property is in the neighborhood
DNR OFR2003-15 Geologic Map of Shelton 1:100,000 Quadrangle, Washington
File: C:Trojeets"wlesslGeo-Rpt 2 of 6 10/11/2011
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
of the steep sloped ravine to the south of the property. The sideslopes of the ravine are solid
and fractured basalt rock, which extends beneath nearly all the properties in the area between
Hoodsport and Lilliwaup. No slides or earth movements have occurred on or within 300-feet
of the Lawless property. Instability of the area is typically associated with cut banks or
stream incised banks, neither of which influences any of the Lawless property.
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2. SITE PLAN WITH IMPORTANT DEVELOPMENT AND GEOLOGIC
FEATURES:
An Onsite Septic System (OSS) resides generally in the location shown on the attached site
plan. The existing septic system presents no problems relating to the site's stability or
geology. No wetlands are present on the Lawless property. A man dug pond is located in the
easterly portion of the property and southeasterly of the steep slopes on the property. The
back wall of the pond has been excavated to a depth as high as 8 to 10 feet, which has stood
at a near vertical incline for over 50 years.
A steep basalt rock ravine with a perennial stream is located approximately 300+ feet
southeast of the Lawless property. The Lawless property is well outside the influence of
either the ravine or the stream. Because of the basalt rock and glacial till substrate underlying
the property, the 46% slope shown on the property is stable and does not represent a
landslide hazard or threat to the Lawless property or improvements. The proposed structure
location shown on the attached site plans is safe in the site's current conditions and proposed
location.
File: C:IProjectslLawlesslGeo-Rpt 3 of 6 10/11/2011
f
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
3. LOCATIONS OF LOGS OF EXPLORATORY HOLES OR PROBES:
Soil exploration probes were performed with a hand driven 4-foot steel rod. Penetration of
the surface soil horizon met moderate resistance, but the soil character turned to a hardpan
character, usually within 2 to 3 feet of the ground's surface. Soil probe locations and depths
are indicated on the attached site plan.
4. AREA OF PROPOSED DEVELOPMENT & BOUNDARIES OF HAZARDS,
BUFFERS, AND SETBACKS:
The 19% slope in the area of the proposed structure location is stable in its present
configuration and condition and does not represent a hazard. The attached plans show the
46% slope area easterly of the Lawless residence labeled as a hazard as required under
Mason County's Resource Ordinance requirements for hillsides with a gradient of 40% or
greater. A 50 foot hazard area buffer line is also shown on the attached plans. Mason County
allows development on a hazard area or within its associated buffer provided stability issues
can or have been mitigated. Mitigation acceptable to the County is a geotechnical report
supporting the proposed property's development, and which shows that the property can be
developed safely in terms of geologic stability. Current standard building setbacks (25' front
& 20' side-yard) are shown on the attached site plans. A 10-foot minimum building setback
from the crest(s) of any slope exceeding 40% is recommended and depicted on the attached
drawings. The proposed structure location is well away from any hazards and is outside of
the hazard area's 50-foot buffer.
5. CROSS SECTION WITH PROPOSED GRADE CHANGES:
A cross section view is provided in the attached plan sheets. This same cross section was
used in the stability analysis model which models the 46% slope. No grade changes are
proposed on any of the steep slopes on the property. Grading in the area of the proposed
structure will be modest, but can be expected to produce short cut and fill slopes. Cut slopes
may be excavated to as steep as 1:1, and fill slopes should be constructed to no greater than
1'/2:1 (V:H). Structure foundations and concrete floor slabs should bear on an undisturbed
soil layer. If fill is required to support a foundation element or a floor slab, it should be
installed under the supervision of a licensed civil engineer or a licensed engineering
geologist.
6. SLOPE STABILITY ANALYSIS:
The steepest slopes on or near the Lawless' property in its present condition contain no
obvious recent mass landslides or stability problem indicators. Trees in the neighborhood are
growing vertically showing no signs of soil movement. The existing leveled building area on
the property is based on the dense cemented till material and has no discernable irregularities,
settlements, fissures, or evidence of consolidation problems.
The stability model is portrayed with two soil layers, a shallow(<3') surface layer of
weathered glacial till, and a deeper soil strata which is modeled as cemented glacial till. Both
soils are composed of generally the same soil components, but the surface soil layer is
modeled with a lower cohesion than ascribed to the till layer. Both soils are modeled with
saturated soil conditions (phreatic surface modeled above the ground's surface).
File: C:TrojectslLawlesslGeo-Rpt 4 of 6 10/11/2011
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Unified Soil Classification System typing places the soils in a dual symbol category due to its
fines content falling above 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 soil characterized with the shallow soil layer having a soil unit weight of 123
lbs/ft3,the glacial till layer having a soil unit weight of 1251bs/ft. Both soil layers are
modeled with a phi angle of 34°. The shallow soil is modeled with a cohesion value of 100
lbs/ft2, and the till layer is modeled with a cohesion character of 300 lbs/ft2. A phreatic
surface is assumed above the ground's surface to mimic saturated surface soil conditions, but
the actual ground water elevation roughly matched the Hood Canal sea level elevation
approximately 300 feet below the Lawless property. The slope geometry and soil
characteristics provide a minimum factor of safety for the site in a static condition of 26+and
a minimum dynamic factor of safety of 12+. Both values exceed the County's minimum
safety requirements.
7. RECOMMENDED SETBACKS & DRAINAGE:
The slope stability analysis indicates that the slopes present on the Lawless property are
stable in their present geometry and conditions and do not represent a landslide or geological
hazard to the proposed Lawless property improvements. A minimum 10-foot building
setback from the crest of the steep slope is recommended.
Drainage from the present site sheets to its natural drainage direction generally to the
southeast into well vegetated areas. This runoff regime should be preserved. Delivery of
concentrated stormwater flows to a slope is not allowed under the requirements of the
County's Resource Ordinance, so the Best Management Practice(BMP)for this site is the
dispersion of collected stormwater as close to its source as possible. Installing splash blocks
at the corners of the proposed structure and sloping the ground away from the structure's
foundation for a minimum of 5 feet should perform acceptably. Driveway and parking area
runoff are directed to the edges of the driveway and parking areas for dispersion into grassed
or vegetated areas of the property. The shallow soil depth to the glacial till precludes any
effective retention of stormwater runoff on the property itself.
8. CLEARING, GRADING,AND VEGETATION MANAGEMENT:
General site grading and preparation for proposed improvements on the property has already
been accomplished, and little, if any,additional clearing or grading will be necessary to
proceed with the site's development.No formal vegetation plan appears needed for the
proposed property development. No structural fills are anticipated for the proposed
improvement.
9. EROSION AND SEDIMENT CONTROL:
Inspection of the Soil Survey of Mason County found the site to be located in an area with
Hoodsport soil type(s), which are not identified in the County's Critical Resource Ordinance
as susceptible to severe erosion when disturbed. A formal site specific Erosion and Sediment
Control (ESC Plan) is not required for sites with non-erodible soils.
Nearly all stormwater runoff will exit the Lawless property over the southeast area of the
property. Runoff from the proposed improvement will have little if any impact on the hillside
File: C:Troje&sUw1ess1Geo-Rpt 5 of 6 10/11/2011
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
or properties down gradient from the Lawless property. Access to the site already exists off
the end of Arnold's Way (a private road) and is stable in its present condition.
10. ON-SITE AND OFF-SITE IMPACTS:
The completed improvements to the Lawless property will not result in any adverse on-site or
off-site impacts.
11. SPECIFICATIONS OF FINAL DEVELOPMENT:
No specific requirements appear needed for the property's proposed improvements, provided
the structure's location does not intrude into the 10-ft hazard setback recommended in this
report. Structure foundations should be founded on the dense soil layer underlying the site. A
formal vegetation management plan does not appear warranted for the proposed site's
development.
12. RECOMMENDATIONS FOR THE PREPARATION OF STRUCTURAL
MITIGATION OR DETAILS OF OTHER PROPOSED MITIGATION:
Modeling of the southeasterly descending slope indicates that the location of the existing and
proposed property improvements are or will be safe. No structural measures or mitigation
measures appear needed.
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 Lawless property does not contain any jeopardizing landslide hazard features, nor is it
within a distance from any identified hazards which would raise a concern. No adverse
impacts are anticipated from the proposed property improvements.
Please feel free to contact me if there are any questions or concerns regarding this report or
my findings. Sincerely, Alan A. Tahja, P.E.
i T
WA
SfONAL E�
Attached: Geotechnical Report Checklist
2 Plan Views & 1 Cross Section View
GALENATM Stability Analysis Printout
File:C:TrojectslLawlesslGeo-Rpt 6 of 6 10/11/2011
Rev# Description Date TAHJA ENGINEERING,INC. SITE PLAN "^`mb
Alan Tahja,P.E. Leonard'Brook"Lawless Lawless
PO Box 235 PO Box 484 Am
HoodspoA WA 98548 HoodspoA WA 98548 1 of3
Mason Co.Prc1 No.:32331-22-00000 (360)877-9512 (360)877-9072
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Rev# Description Date TAHJA ENGINEERING,INC. SITE PLAN P4°°'
Alan Tabja,P.E. Leonard'Brook"Lawless Lawless
PO Box 235 PO Box 484
HoodspoA WA 98548 HoodspoA WA 98548 2 of 3
Mason Co.Prel No.:32331 22-00000 (360)877-9512 1 (360)877-9072
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Rev# Description Date TAHJA ENGINEERING,INC. CROSS SECTION P*J%
Alan Tahja,P.E. Leonard'Brook"Lawless Lawless
PO Box 235 PO Box 484
Hoodsport, WA 98548 Hoodspoit WA 98548 3 of 3
Mason Co.RW No.:32331-22-00000 (360)877-9512 (360)877-9072
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TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Lawless X-Section A-A Static Stability Analysis
GALENA ve,roe5.o2
1300
Sso
500 7sreatic Surface WA
450 �4 O
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400 \
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350
300 Develop-t Area ���{' `rGCS TEg�'`9
•3-Thick weathered Soil Layer �s`SI0 L F+��
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Cemented Glacial TI11 Subs[� '
200 _....".".....
Analvsis 1
1 Multiple Stability Analysis
Method: Bishop Simplified
Surface: Circular
100
Resuhs
Critical(minimum)
50
Fedor of Safety: 26.26
0 100 200 300 400 500 600 700 800
EJ1ed 100,12011 P-bleed:10002011
Proiect Lawless Restawhile Stability Analysis
Static
Eik C:Oocuments and SeWngs\Owner\My Documents\Galena Files\Models\Lawless S1.gmf 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 Layer
Cohesion Phi UnitWeight Ru
100.00 34 .0 123.00 1.10
Material: 2 (Mohr-Coulomb Isotropic) - Cemented Glacial Till Substrate
Cohesion Phi UnitWeight Ru
300.00 34.0 125.00 1.10
Water Properties ------------
Unit weight of water: 6.00 Unit weight of water/medium above ground: 62.40
Material Profiles (2 profiles) -----------------
Profile: 1 (2 points) Material beneath: 1 - Weathered Surface Soil Layer
0.00 450.00 800.00 450.00
Profile: 2 (10 points) Material beneath: 2 - Cemented Glacial Till Substrate
0.00 327.00 162.30 307.00 301.40 287.00
351.90 277.00 409.30 257.00
478.40 237.00 521.70 227.00 581.10 217.00
657. 60 207.00 752. 60 197.00
Slope Surface (10 points) ---------
0.00 330.00 162.30 310.00 301.40 290.00
351. 90 280.00 409.30 260.00
478.40 240.00 521.70 230.00 581.10 220.00
657 . 60 210.00 752.60 200.00
File:C:IProjectsUwlessl X-Sec A-A Analysis Printout I of 4 10/1 1/201 1
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Phreatic Surface (2 points) --- 0.00 455.00 800.00 455.00
Failure Surface ---------------
Initial circular surface for critical search defined by: XL,XR,R
Intersects: XL: 350.00 YL: 280.38 XR: 470.00 YR: 242.43
Centre: XC: 422.30 YC: 300.31 Radius: R: 75.00
Variable Restraints -------------------
Parameter descriptor: XL XR R
Range of variation: 110.00 110.00 50.00
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: 33. 96
There were: 1133 successful analyses from a total of 1729 trial circles
596 analyses terminated due to unacceptable geometry
Critical (minimum) Factor of Safety: 26.26
Circle and Results Summary (Lowest 17 Factor of Safety circles)
--------------------------
Circle X-Centre Y-Centre X-Left Y-Left X-Right Y-Right
Radius FoS
1 402.80 310.17 305.00 289.29 475.00 240. 98
100.00 26.261
2 412.89 307.76 315.00 287.31 485.00 238.48
100.00 26.310
3 411.19 265.00 345.00 281.37 475.00 240.98
68.18 26.366
4 392.57 312.83 295.00 290.92 465.00 243.88
100.00 26.433
5 404. 62 297.97 305.00 289.29 485.00 238.48
100.00 26.446
6 414. 65 295.69 315.00 287.31 495.00 236.17
100.00 26.551
7 394.55 300.38 295.00 290.92 475.00 240. 98
100.00 26.559
8 422.94 305.50 325.00 285.33 495.00 236.17
100.00 26.634
9 421. 14 262.37 355.00 278. 92 485.00 238.48
68. 18 26. 638
10 414.37 276.13 315.00 287.31 505.00 233.86
100.00 26.729
11 404.42 278.54 305.00 289.29 495.00 236.17
100.00 26.808
12 424.32 273.71 325.00 285.33 515.00 231.55
100.00 26.848
13 424 .67 293.42 325.00 285.33 505.00 233.86
100.00 26.874
14 410.39 317.31 315.00 287.31 475.00 240.98
100.00 26. 918
15 400. 16 320.01 305.00 289.29 465.00 243.88
100.00 26. 958
16 409.92 297.42 315.00 287.31 485.00 238.48
95.45 27.014
17 399.87 299.86 305.00 289.29 475.00 240.98
95.45 27.018
File:C:IProjectslLawlessl X-Sec A-A Analysis Printout 2 of 4 10/1 1/201 1
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Lawless X-Section A-A Dynamic Stability Analysis
GALENA v.me05.02
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Analysis: 1
Multiple Stability Analysis
Method: Bishop Simplified
Surface: Circular
100
Results
Critical(minimum)
Factor o/Safety. 12.98
0 100 200 300 400 500 600 700 B00
EQ'ed.100d2011 Roc d 100d2011
Protect Lawless Restawhile Stability Analysis
Dynamic
E& C Oourments and SetbngsXCwnerWy Documents\Galena FilesWodelsU"ess Dt.gmf Tahla 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 Layer
Cohesion Phi UnitWeight Ru
100.00 34.0 123.00 1.10
Material: 2 (Mohr-Coulomb Isotropic) - Cemented Glacial Till Substrate
Cohesion Phi UnitWeight Ru
300.00 34.0 125.00 1.10
Water Properties ----------------
Unit weight of water: 6.00 Unit weight of water/medium above ground: 62.40
Material Profiles (2 profiles) -----------------
Profile: 1 (2 points) Material beneath: 1 - Weathered Surface Soil Layer
0.00 450.00 800.00 450.00
Profile: 2 (10 points) Material beneath: 2 - Cemented Glacial Till Substrate
0.00 327.00 162.30 307.00 301.40 287.00
351. 90 277.00 409.30 257.00
478.40 237.00 521.70 227.00 581.10 217.00
657.60 207.00 752. 60 197.00
Slope Surface (10 points) -------------
0.00 330.00 162.30 310.00 301.40 290.00
351.90 280.00 409.30 260.00
478.40 240.00 521.70 230.00 581.10 220.00
657.60 210.00 752. 60 200.00
File: C:IProjectsl[.awlessl X-Sec A-A Analysis Printout 3 of 4 10/11/2011
I
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Phreatic Surface (2 points) ---- 0.00 455.00 800.00 455.00
Failure Surface ---------------
Initial circular surface for critical search defined by: XL,XR,R
Intersects: XL: 350.00 YL: 280.38 XR: 470.00 YR: 242.43
Centre: XC: 422.30 YC: 300.31 Radius: R: 75.00
Earthquake Force ----------------
Pseudo-static earthquake (seismic) coefficient: 0.150
Variable Restraints -------------------
Parameter descriptor: XL XR R
Range of variation: 110.00 110.00 50.00
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: 17.40
There were: 1133 successful analyses from a total of 1729 trial circles
596 analyses terminated due to unacceptable geometry
Critical (minimum) Factor of Safety: 12. 98
Circle and Results Summary (Lowest 16 Factor of Safety circles) ------------------
Circle X-Centre Y-Centre X-Left Y-Left X-Right Y-Right
Radius FoS
1 392.57 312.83 295.00 290. 92 465.00 243.88
100.00 12. 978
2 394 .55 300.38 295.00 290. 92 475.00 240. 98
100.00 13.029
3 402.80 310.17 305.00 289.29 475.00 240.98
100.00 13.038
4 404.62 297. 97 305.00 289.29 485.00 238.48
100.00 13.094
5 412.89 307.76 315.00 287.31 485.00 238.48
100.00 13.162
6 414 . 65 295. 69 315.00 287.31 495.00 236.17
100.00 13.211
7 389.84 322. 63 295.00 290. 92 455.00 246.77
100.00 13.326
8 389.74 302.59 295.00 290.92 465.00 243.88
95.45 13.352
9 422. 94 305.50 325.00 285.33 495.00 236.17
100.00 13.363
10 424 .67 293.42 325.00 285.33 505.00 233.86
100.00 13.381
11 399.87 299.86 305.00 289.29 475.00 240. 98
95.45 13.395
12 400.16 320.01 305.00 289.29 465.00 243.88
100.00 13.399
13 387.54 314 .31 295.00 290. 92 455.00 246.77
95.45 13.426
14 397.79 311. 66 305.00 289.29 465.00 243.88
95.45 13.480
15 409. 92 297.42 315.00 287.31 485.00 238.48
95.45 13.493
16 410.39 317.31 315.00 287.31 475.00 240. 98
100.00 13.506
File:C:IProjectslLawlessl X-Sec A-A Analysis Printout 4 of 4 10/1 1/201 1