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Home My WebLink AboutGeological Assessment and Modification of Geo-Tech Report - BLD Engineering / Geo-tech Reports - 10/16/2006 CONSULTANTS, LLC . } n Environmental Engineering • Geotechnical Engineering • Wetland Consulting October 16, 2006 Project No.ACL06-07-GO62 Mr. Jeremy Schintz 3561 SW Camas Lane �� „ Port Orchard, Washington 98367 ?�V Subject: Modification of Geological Assessment to Geotechnical Report �Z, Parcel#22205-75-00040 Nq A CO 290 Cheyenne Hill Drivelr Belfair, Washington Mr. Schintz, The following is a letter to modify our original Limited Geologic Assessment Report dated July 7,2006 to a Geotechnical Report. This letter is in response to a Mason County Inter-Departmental Communications Letter dated August 27, 2005 that was forwarded to ALKAI by yourself. The content of a Geotechnical Report as required by Mason County Resource Ordinance Chapter 17.01.100.E.5 is as follows: (1) A discussion of general geologic conditions, specific soil types, groundwater conditions, and history of landslide activity. Included under Site Surface and Subsurface Conditions on Page 2 of Limited Geologic Assessment Report by ALKAI consultants dated July 7,2006. ije(2) A site plan which identifies important development and geologic features. See Figure 1,Site Plan following this report. (3) Locations and logs of exploratory holes or probes. The vertical river cut bank along the Tahuya River J , north of the proposed development provided an excellent exposure for examination of the site's glacial deposits and groundwater conditions. The soils are dense to very dense glacial at approximately 2 feet below existing ground surface. Underlying the glacial till to the bottom of the cut bank is glacially consolidated outwash sand. Slow groundwater seepage was observed approximately 20 feet above the bottom of the bank. Another exposure in an existing road cut to the west of the proposed residence indicates that the glacial till deposits are also present on the area of the west slope illustrated on the cross section. VJ(4) A minimum of one cross section at a scale which adequately depicts the subsurface profile, and which incorporates the details of the proposed grade changes. No grade changes are proposed except cuts and fills of 1 to 2 feet for the gravel road and shallow grading for the house foundation. See Figures 2 and 3 following this report for cross sections. (5) A description and results of slope stability analysis performed for both seismic and static loading conditions. A quantitative slope stability analysis has not been prepared at the time of this report,but could be performed in the near future. A qualitative analysis indicates that a high safety factor exists for both static and seismic conditions due to the distance of the road,proposed residence and proposed drainfield from steep slopes. (6) Appropriate restrictions on placement of drainage features, septic drain fields, and compacted fills and footings, including recommended from shoreline bluffs and the tops of other slopes on the property. Energy dissipater features for areas of stormwater discharge such as splash blocks and quarry spalls. No restrictions for septic drain fields as the proposed location is at an adequate distance from any slopes. No structural fill is anticipated. Footings are to bear on dense native soil(likely at approximately 2 feet GEOLOGIC AND GEOTECE IICAL CONSULTING Ueotechnical Reporto t ica ion 290 Cheyenne Hill Drive October 16,2006 Page No.2 below existing ground surface). The slope setbacks for the structures are adequate for slope stability nd the stability of the structures. m.. (7) etaile c Baring and grading plan which specifically identifies vegetation to be removed, a schedule for vegetation removal and replanting, and the method for vegetation removal. Site grading is expected to be minimal and vegetation removal consists of grassy vegetation. Disturbed areas should be covered with straw or protected with visqueen during construction. A minimum of a grass lawn should be replanted following construction. No specific schedule is recommended and work may be performed as weather conditions permit. (8) A detailed temporary erosion control plan which identifies the specific mitigation measures to be implemented during construction to protect the slope from erosion, landslides, and harmful construction methods. As noted in item#7. (9) An analysis of both on-site and off-site impacts of the proposed development. No future impacts on-site or off-site are anticipated as long as temporary erosion methods are followed and vegetation is maintained following construction. (10) Specifications of final development conditions such as vegetative management, drainage, erosion control, and buffer widths. Vegetation should be maintained following construction activities. Drainage features should be equipped with energy dissipaters at the points of discharge. Erosion control will be managed by maintaining vegetation. The proposed buffers are adequate. Should you have any questions or concerns, which have not been addressed, or if we may be of additional assistance, please call our office at(360)613-2407. Sincerely, � 07 1 1121 %9ed Geo David Hurum, L.G. Shawn E. Williams,L.E.G. Senior Licensed Geologist r gDAVI/D C. HURUM Senior Engineering Geologist s:\departments\geotech\projects\06 projects\ac106-07-g062 hurd road\hurd road geotech update ac106-07-gO62.doc ALKAI Consultants, LLC 9465 • Provost Road NW, Suite 202 • Silverdale,Washington 98383 • Ph.: (360) 613-2407 • Fax: (360) 613-2408 t r � 183 feet to ` J top of slope o shown on north slope cross section .y , J - , 1 .........-.. .:. 105 feet to top of slope .:- shown p 0 on we ,St s slone deo� 8� �r orb '`,♦ I Y10 Owner/Applicant: Jeremy Schintz Parcel#122017111040 Figure adapted from plan provided by client. FIGURE 1 SITE PLAN Project Name: Hurd Road Residence ALKAI CONSULTANTS, LLC. Location: Belfair,Washington Project No.: ACL 06-07-GO62 Environmental Engineering• Geotechnical Engineering•Wetland Consulting Client: Mr.Jeremy SChIntZ Date: 10/10/06 Original Top of Bank in Small Ravine Closest Point of Easement Road Area/Current Top of Bank in Other Areas Proposed House 180 F et 'q From Ravine a,� i Small Ravine Area ., H 75 Soils Dense Glacial Till Feet and Outwash :::i.•f<f;•::fa:' :: s f f"t ;'T f f$tiTi'» �::;,,:.;�.:LT, b�+ FtF..P.:.�f'•6,�.;.B:t• tl:,;.f,^•by°{ 'd�f�; �-,"s�f`fA'�64iff�if i• ;;i�' bif:fkb .•f b[fi•:�L.yE:e��bf'e:.,fBE:�-";}'i•Rf�if`F'�-yb B'F:•€,'f:,:•'•;.LsfSf• f:,•�,�ti;•fifFi:f•E •fff.•$ .b'b,f:+ "a6�°v:-f<':f:fi��°+%':�.'rt`b:dif:s:f:4°f Slow Seepage 51 10• 15' 11 Figure generated from field measurements by ALKAI Consultants Toe of Bank at Tahuya River using a fiberglass tape and Brunton Pocket Transit. FIGURE 2 CROSS SECTION, NORTH SLOPE ALKAI CONSULTANTS, LLC. Project Name: Hurd Road Residence Location: Beifair,Washington V-1 _t Environmental Engineering. Geotechnical Engineering•Wetland Consulting Project No.: ACL 06-07-GO62 Client: Mr.Jeremy Schintz Date: 10/16/06 Closest point of Closest point of Proposed Drainfield Proposed Residence Closest Proposed Development Beyond A 2 Horizontal:I Vertical Zone of Influence 55 feet a:i'.:?it.?<.,6,. t'S i•;3°�>p,°��..�YS':6 ff fF t + F��56.6.o:?ib'6.{:t"'Y 'i�L G eG F'�6�ft6•'6�?'•k:f't Dense Glacial Till and Outwash [Toe of Slope Figure generated from field measurements by ALKAI Consultants using a fiberglass tape and Brunton Pocket Transit. FIGURE 3 CROSS SECTION,WEST SLOPE ALI�A1 CONSULTANTS, LLC. Project Name: Hurd Road Residence . F Location: Belfair,Washington Environmental Engineering•Geotechnical Engineering•Wetland Consulting Project No.: ACL 06-07-GO62 Client: Mr.Jeremy Schintz Date: 9/19106 ALKAI ,- . _. I.I.C. eotechnical Engineering Report CONSULTANTS is 290 Cheyenne Hill Drive Belfair, Washington Project# ACL06-07-G062 Prepared for: Jeremy Schintz • Environmental Engineering 11 • Geotechnical Engineering • Wetland Consulting • • 1 • 1 J GE07IECHM(CA L IENMNE ER N(G REPO 1 7 7AX PARCEL M No. 22205-75-00040 PROPOSED SINGLE ]FAMILY RESH)ENCE 290 (CHEIYENNE HILL IDLE BELIFAIR, WASHIEiGTON Prepared Ton JEREMY SCHINTZ 3561 SW CAMAS LANE PORT ORCHARD,WASHINGTON 98367 Prepared by: ALKAI CONSULTANTS, LLC 9465 PROVOST ROAD NW, SUITE 202 SILVERDALE,WASHINGTON 98383 Project No.ACL06-07-G062 21 November 2006 ALKAI CONSULTANTS LLC. Environmental Engineering • Geotechnical Engineering • Wetland Consulting 21 November 2006 Project: ACL06-07-GO62 Mr.Jeremy Schintz 3561 SW Camas Lane Port Orchard,WA 98367 Subject: Geotechnical Engineering Report Proposed Single Family Residence Parcel#22205-75-00040 290 Cheyenne Hill Drive Belfair, Washington Dear Mr. Schintz, Submitted herewith is a report for ALKAI Consultants, LLC's geotechnical engineering report for the subject project. The report presents findings from our geotechnical engineering investigation and provides recommendations for geotechnical engineering aspects of project design. We appreciate the opportunity to work with you on this project. If we can be of further assistance, or if you have any questions regarding this project,please contact our office. Sincerely yours, PA 4 OV WAS o Todd S. Parkington, E. y 1tI� Senior Geotechnical Engineer Enclosures '�s' 360 y SIONAL EXPIRES 5/01/J 9465 Provost Road NW, Suite 202 • Silverdale, Washington 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project: ACL06-07-GO62 21 November 2006 Page No. i TABLE OF CONTENTS Page LIST OF FIGURES ii 1.0 INTRODUCTION 1 1.1 Site Location 1 1.2 Proposed Construction 1 1.3 Purpose 1 2.0 SITE INVESTIGATION 1 2.1 Site Description 1 2.2 Geologic Setting 1 2.3 Subsurface Exploration 2 2.3.1 Soil 2 2.3.2 Groundwater 2 2.4 Seismic Information 2 3.0 CONCLUSIONS AND RECOMMENDATIONS 2 3.1 Slope Stability 2 3.2 Erosion Control 3 3.3 Drainage 3 3.4 Earthwork Considerations 3 3.4.1 Site Preparation 3 3.4.2 Groundwater Concerns 4 3.4.3 Excavations&Temporary Slopes 4 3.4.4 Structural Fill 4 3.4.5 Utility Trench Fill 4 4.0 LIMITATIONS 4 FIGURES 9465 Provost Road NW, Suite 202 • Silverdale, Washington 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project: ACL06-07-G062 21 November 2006 Page No. ii LIST OF FIGURES Figure No. Title 1 Vicinity Map 2 Site Plan 3 Slope Profile 4 Slope Stability Analysis, Static Conditions 5 Slope Stability Analysis, Seismic Conditions `I�?i` Provost Road NW, Suite 202 • Silverdale, Washington 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No.ACL06-07-GO62 21 November 2006 Page No. 1 1.0 INTRODUCTION ALKAI Consultants, LLC (ALKAI) was retained by Mr. Schintz to conduct a geotechnical engineering investigation for the proposed Single Family Residence in Belfair, Washington located in Mason County. 1.1 Site Location The site is located in Mason County off of NE Cheyenne Hill Drive. Hurd RoaProvides access to NE Cheyenne Hill Drive. According to the United States Geologic Survey (USGS), 7.5 minu a Lofall uadrant, Washington topographic /4 quadrangle map, the property is located in the NE ' of the SW '/4 of Section 5, ownship 22 North, Range 2 West, W.M. and at Longitude 122.96 degrees W and Latitude 47.42 degrees N. The site location is shown on the Site Vicinity Map, Figure 1. 1.2 Proposed Construction We understand that the proposed development is to consist of a single family residence and associated infrastructure and relocation of an existing gravel driveway. The location of the proposed residence and the existing driveway are shown on the Site Plan, Figure 2.. We further understand that relocation of the existing driveway will be away from the top of the steep slope above the Tahuya River. We understand that general site grading for development will be minimal. Foundation loads were not provided. However,we assume that the residence will be no more than two stories high and of light wood frame construction. 1.3 Purpose The purpose of this investigation was to estimate the impact of the proposed development on the steep slope below the building site next to the Tahuya River and to provide recommendations for the geotechnical aspects of the project. 2.0 SITE INVESTIGATION 2.1 Site Description The parcel is bound to the north by the Tahuya River to the north,undeveloped property to the south and east,and a single family residence to the west. A near vertical river cut bank is located toward the north end of the property along the Tahuya River. The cut bank is approximately 75 feet high (See Figure 3, Slope Profile). There is a small ravine 1 perpendicular to the cut bank that appears to be a channel for natural seasonal surface water run-off. Vegetation consists of cedar,alder,and maple trees with understory vegetation consisting of sword fern and Oregon grape. 2.2 Geologic Setting The Washington Division of Geology and Earth Resource (WDGER), Geologic Map of Washington - Northwest Quadrant, dated 2002, indicates that the site lies on glacial till with advanced outwash exposed in the slopes along the Tahuya River. In general, glacial till consists of an unsorted, unstratified, highly compacted mixture of clay, silt, sand, gravel, cobbles, and boulders deposited by glacial ice and may contain interbedded stratified sand, silt, and gravel. Advanced outwash consists of sand and gravel and lacustrine silt and clay deposited as glaciers advanced. The United States Department of Agriculture (USDA) Soil Conservation Service Soil Survey of Mason County Area, Washington, indicates that the river bank is mapped as rough broken land. The soils on the plateau above the Tahuya River are mapped as Cloquallum silt loam with 5 to 15 percent slopes. This soil originated in lacustrine deposits and glacial drift. A review of the Folio of the Southern Hood Canal Area was performed in preparing this study. The site is mapped as Class 1 slopes. Class 1 slopes are generally less than 15 percent, but may be steeper in localized areas and are believed to be stable. 9465 Provost Road NW, Suite 202 • Silverdale, Washington 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No.ACL06-07-GO62 21 November 2006 Page No. 2 2.3 Subsurface Exploration ALKAI did not excavate any test pits or boreholes for this report. The near vertical river cut bank along the Tahuya River �north of the proposed development provided an excellent exposure for examination of the site's glacial deposits and groundwater conditions. Another exposure in an existing road cut to the west of the proposed residence provided additional subsurface information. 2.3.1 Soil The soils are dense to very dense glacial till from approximately 2 feet below the existing ground surface. Underlying the glacial till to the bottom of the cut bank is glacially consolidated outwash sand. 2.3.2 Groundwater Slow groundwater seepage was observed approximately 20 feet above the bottom of the bank. Water table elevations fluctuate with time, being dependent upon seasonal precipitation, irrigation, land use, and climatic conditions, as well as other factors. Therefore, water level observations at the time of the field investigation may vary from those encountered during the construction phase of the project. The evaluation of such factors is beyond the scope of this report. 2.4 Seismic Information ALKAI has reviewed section 1615.1 of the 2003 International Building Code (IBC). Site specific data is not available to a depth of 100 feet. As the site soils consist of glacial till and glacially consolidated outwash to a depth of 75 feet, we estimate that the average Standard Penetration Resistance for the top 100 feet of site soils is greater than 50. Therefore, for seismic design of structures the site should be considered class C, "very dense soil and soft rock", as defined in the IBC. - Ground motion accelerations for the site were obtained from the USGS Earthquake Hazards Program website and are presented in the following table. The latitude/longitude method was used to obtain the ground motions with a latitude of 47.42 degrees and a longitude of 122.96 degrees using the 2002 data tables. Probability of Exceedance 10%in 50 years 2% in 50 years Peak Ground Acceleration(PGA) 0.326 g 0.567 0.2 second period SS 0.713 g 1.248 I second period(Sl) 0.255 g 0.479 3.0 CONCLUSIONS AND RECOMMENDATIONS 3.1 Slope Stability ALKAI performed a slope stability analysis on a cross section as illustrated on Fri Pre 33 Slope Profile. Topography used in the analysis was based on measurements made by ALKAI personnel in the fie—Id and should be considered approximate. The analysis was conducted using the commercially available software GSTABL7 with STEDwin by Gregory Geotechnical Software. Soil strength parameters were based on partially on published values. Our analysis assumed that groundwater was present in the slope from the level where water was seeping out of the near vertical bank. The pseudostatic method was used for our slope stability analysis to estimate the safety factor under seismic conditions. The seismic coefficient used in a pseudostatic analysis is typically taken to be '/z of the PGA that the site is estimated to experience during the design earthquake. For this project we chose a design earthquake that would produce ground motions with a 10 percent probability of exceedance in 50 years. As indicated in Section 2.4 above the corresponding PGA is 0.326 g. Therefore the seismic coefficient used in our analysis was 0.163 g. The results of slope stability analyses are expressed as factors of safety against displacement failure. The factor of safety is the ratio of resisting forces to driving forces. A factor of safety of 1.0 is equilibrium; a factor of safety of less than 1.0 indicates failure. Typically, a factor of safety of 1.5 for static conditions and 1.1 for seismic (pseudostatic) conditions is 9465 Provost Road NW, Suite 202 9 Silverdale, Washington 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No.ACL06-07-G062 21 November 2006 Page No. 3 considered adequate. Factors of safety between 1.0 and 1.5 (or 1.1) are not adequate due to the uncertainties in the modeling process. A lower safety factor for seismic conditions is adequate as the probability of occurrence of the seismic conditions analyzed is relatively low. We selected initial values for the soil strength parameters based on published values for glacial till and advance outwash. We then varied the parameters until we found a minimum safety factor of approximately 1.0. This corresponds to an assumption that the near vertical bank is at equilibrium. We then repeated the analyses for slip surfaces that would intersect the nearest approach of the gravel driveway or the proposed residence. The result of our analysis indicates a minimum static factor of safety of 1.88 and minimum seismic factor of safety of 1.57. Graphical representations of the results of our static and seismic slope stability analyses are presented on Figures 4 and 5,respectively. Based on the results of our slope stability analysis, the proposed construction has an adequate factor of safety against slope movement for slip surfaces that might intersect either the gravel road or the proposed residence. The proposed construction will not decrease the stability of the steep slope. 3.2 Erosion Control Vegetation on or near the top of the slope should be disturbed as little as possible. In addition, construction should be conducted in such a way as to ensure that storm water runoff does not flow over the top of the slope. Best management practices, such as silt fences at the construction site perimeter, should be used to prevent silt laden water from entering surface waters or storm water disposal systems. The Washington State Department of Ecology (DOE) has three publications, which may be helpful in developing long- term slope vegetation maintenance/protection and landscape plans: • "Slope Stabilization and Erosion Control Using Vegetation: A Manual of Practice for Coastal Property Owners", May 1993,Publication 93-30. • "Vegetation Management: A Guide for Puget Sound Bluff Property Owners",May 1993,Publication 93-31. • 'Surface Water and Ground Water on Coastal Bluffs: A Guide for Puget Sound Property Owners", June 1995, Publication 95-107. Although the site is not on the coast,the preceding publications provide a wealth of information on the best types of plants to minimize erosion hazards. 3.3 Drainage Runoff from buildings and impervious surfaces should be directed into an appropriately designed storm water disposal system. Design of storm water disposal systems is primarily the responsibility of a civil engineer. Based on the glacial till exposed in the near vertical bank, we anticipate that infiltration will not be an option for storm water disposal. Infiltration in advance outwash might be feasible, if it is present at an appropriate location. 3.4 Earthwork Considerations During wet weather conditions, typically October through April, subgrade stability problems and grading difficulties may develop due to high moisture content in the soil, disturbance of sensitive soils and/or the presence of perched groundwater. 3.4.1 Site Preparation General site clearing should include removal of vegetation, trees and associated root systems, wood, pavement, retaining walls, rubble, and rubbish. Site clearing should not extend into the native vegetation buffer. Site stripping should extend to a minimum depth of 4 inches,or until all organics in excess of 3 percent by volume are removed. Deeper stripping may be required in localized areas. These materials will not be suitable for use as fill for parking or building areas. However, stripped topsoil may be stockpiled and reused in landscape or non-structural areas. 9465 Provost Road NW, Suite 202 • Silverdale, Washington 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No.ACL06-07-GO62 21 November 2006 Page No.4 Any buried structures encountered during construction should be properly removed and backfilled. Excavation, depressions, or soft and pliant areas extending below planned finish subgrade level should be cleaned to firm, undisturbed soil and backfilled with structural fill to planned finish subgrade. 3.4.2 Groundwater Concerns Groundwater was noted seeping from the face of the near vertical bank approximately 20 feet above the level of the Tahuya River. As this elevation is approximately 55 feet below the level at which the house will be constructed, we do not anticipate that groundwater will impact construction. However, should groundwater be encountered during construction,we should be notified immediately. 3.4.3 Excavations&Temporary Slopes It is our opinion that the glacial till and advance outwash exposed in the near vertical bank constitute a Type A material as defined by the Washington Industrial Safety and Health Act's(WISHA)regulations on excavation,trenching and shoring. Temporary slopes excavated in Type A material should be inclined no steeper than 3/4H:1V (horizontal:vertical). Permanent cut and fill slopes should be inclined no steeper than 2H:1V, regardless of the material type. A representative of our firm should evaluate temporary and permanent slopes to ensure that they are appropriate for the soils encountered during construction. In areas where it is not possible to maintain the recommended slopes due to space constraints, temporary shoring will be required. Such shoring will need to be properly designed by an engineer. Based on our understanding of the proposed construction, we do not anticipate any significant grading or excavation of the site. If this understanding is incorrect,we should be contacted for additional recommendations. 3.4.4 Structural Fill The on-site soils are generally suitable for use as structural fill, provided they are relatively free from organic material and debris. They may be difficult to compact due to moisture content. Imported structural fill should consist of well-graded gravel and/or sand with a maximum grain size of I'/2 inches and less than 5 percent fines. Structural fill should be placed in loose lifts no more than 12 inches thick, moisture conditioned as necessary (moisture content of soil should be within 2 percent of optimum moisture) and compacted to 95 percent of the maximum dry density as determined by ASTM Test Method D-1557. Additional lifts should not be placed if the previous lift did not meet the required dry density or if soil conditions are not stable. Note that, although density testing of fill is frequently used as the primary criteria for acceptance of fill, it should not be the only criteria. If, in the judgment of the geotechnical engineer or his representative,placed fill is not suitable it should be rejected regardless of density test results. As an example, fill that is compacted wet of the optimum moisture content may exhibit "pumpy" behavior even if density test results indicate better than 95 percent compaction has been achieved. In such a situation, the fill should be removed and replaced with drier material. 3.4.5 Utility Trench Fill Where utility trenches are beneath buildings or pavements, the utility trench fill should consist of structural fill placed and compacted as described above. 4.0 LEVIITATIONS This report has been prepared for Jeremy Schintz regarding the subject project. Information presented in this report has been collected and interpreted in a manner consistent with the level of care and skill ordinarily exercised by members of the profession currently practicing under similar conditions, and in accordance,with sound and generally accepted 9465 Provost Road NW, Suite 202 9 Silverdale,Washington 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 Project No.ACL06-07-GO62 21 November 2006 Page No. 5 principles consistent with normal consulting practice. No other warranty, expressed or implied, including(but not limited to)any warranty or merchantability or fitness for a particular use has been made. Mr. Schintz and ALKAI discussed the risks and rewards associated with this project, as well as ALKAI's fee for services. Mr. Schintz and ALKAI agreed to allocate certain of the risks so that, to the fullest extent permitted by law, ALKAI's total aggregate liability to Mr. Schintz is limited to $50,000 or the fee, whichever is greater, for any and all injuries, claims(including any claims for costs of defense or other incurred costs), losses, expenses, or damages whatsoever arising out of or in any way related to ALKAI's services for this project, from any cause or causes whatsoever, including but not limited to, negligence, errors, omissions, strict liability, breach of contract, breach of warranty, negligent misrepresentation,or other acts giving rise to liability based upon contract tort,or statute. In the event that change in the nature,design, or location of the proposed construction is made, or any physical changes to the site occur, recommendations are not to be considered valid unless the changes are reviewed by ALKAI and conclusions of this report are modified or verified in writing. The subsurface exploration logs and related information depicts conditions only at the specific locations and at the particular time designated in the report. The passage of time may result in a change of subsurface conditions at these exploration locations. Subsurface conditions at other locations may differ from conditions occurring at the exploration locations. The nature and extent of variations of subsurface conditions between explorations are not known. If variations appear during additional explorations or construction,reevaluation of recommendations in this report may be necessary. Stratification lines designating the interface between soil types in subsurface exploration logs represent approximate boundaries. The transition between materials may be gradual. Analyses and recommendations provided in this report are based in part upon the data obtained from the subsurface explorations. The scope of ALKAI services did not include an environmental assessment for the presence or absence of 1) hazardous and/or toxic materials, in the soil,groundwater,surface water,or atmosphere, and 2)wetlands. Any statements or absence of statements in this report on any subsurface exploration log regarding staining or odor of soil, groundwater, or surface water,unusual or suspicious items, or conditions observed are strictly descriptive information for Felton,LLC SAAlkai Shared Files I\ALKAI Shared Files 2\Projects\Geotechnical\06 Projects\ACL06-06-G052 Hick Ave NE\report\Hick Ave G052.doc 9465 Provost Road NW, Suite 202 • Silverdale, Washington 98383 Phone: (360) 613-2407 Fax: (360) 613-2408 � � 1 t jam-.` -r L 1 /f-'�_ ,.--'.- � � fir^ � � �t LLL,,,...✓✓✓ ! _`" -'�n..'-`��` ' r•�rfn"` • •b 4 - SITE ;�,-�/�,�j� / /� ( dGa of vIY \ y'vi 7 � � Figure adapted from TopoZone.com FIGURE 1 VICINITY MAP Project Name: Hurd Road Residence A LK A I CONSULTANTS, LLC. Location: Belfair, Washington N InVt10nTOntil Engineering• Gootechnlcal Engineering•Wetland Consulting Project No.: ACL 06-07-GO62 Client: Mr. Jeremy Schintz Date: 11/21/06 15. ' 183 feet to a top of slope +- shown on slope profile ' x. ' I - 0 Owner/Applicant: Jeremy Schintz f. Parcel#222057500040 Figure adapted from plan provided by client. FIGURE 2 SITE PLAN Project Name: Hurd Road Residence A L K A I CONSU LTANTS, LLC. Location: Belfair,Washington Project No.: ACL 06-07-GO62 Environmental Engineering•GtoHchniml Engineering•Wetland ConsultingClient: Mr.Jeremy Schintz Date: 11/21/06 Original Top of Bank in Small Ravine Proposed House 180 Feet Closest Point of Easement Road Area/Current Top of Bank in Other Areas From Ravine Small Ravine Area 75 Soils Dense Glacial Till Feet and Outwash SCALE 1 inch 20 feet Looking East �' Slow Seepage 5' IU IS' 2U' Figure generated from field measurements by ALKAI Consultants Toe of Bank at Tahuya River using a fiberglass tape and Brunton Pocket Transit. FIGURE 3 SLOPE PROFILE L� f'1 CONSULTANTS. LLC. Project Name: Hurd Road Residence Location: Belfair,Washington Environmental Engineering•Geotechnical Engineering•Wetland Consulting Project No.: ACL 06-07-GO62 Client: Mr.Jeremy Schintz Date: 11/21/06 Hurd Road North Slope Minimum soil parameters s:ldegartments\geotech\projects\06 projects\ac106-07-gO62 hurd road\slope stability\road-house impact.pl2 Run By:Todd Parkington,Alkai Consultants 11/21/2006 03:17PM # FS S oil Soil Total Saturated Cohesion Friction Pore Pressure Piez. a 1.879 Desc. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface b 2.050 No. (pcf) (pcf) (psf) (deg) Param. (psf) No. c 2-255 Till 1 135.0 140.0 1050.0 45.0 0.00 0.0! W1 d 2.596 150 --e_2..757 f 3.026 g 3.240 a h 3.640 i. h Ifl i 3.869 dlb�4 c 5�'� 125 I i � I i 100 I 75 i i 211 I I 1 ! I I ! I I I 25 - i i t 0 0 25 50 75 100 125 150 175 200 225 250 GSTABL7 v.2 FSmin=1.879 Safety Factors Are Calculated By GLE (Spencer's) Method (0-2) GSTABL7 Hurd Road North Slope Minimum soil parameters s:\dep175ents\geotech\projects\06 projects\ac106-07-gO62 hurd road\slope stability\road-house impact-seismic.p12 Run By:Todd Parkington,Alkai Consultants 11/21/2006 03:38PM # FS Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Load Value a 1.570 Desc. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface Peak(A) 0.326(g) b 1.965 No. (pcf) (pcf) (psf) (deg) Param. (psf) No. kh Coef. 0.163(g)< c 2-022 Till 1 135.0 140.0 1050.0 45.0 0.00 0.0 W1 d 2.111 150 e500.00 _ f 500.000 g500.000 a h 500.00 ;; I i i 500.00 9 d1 e f 125 I 100 75 - - — % — — — — - - - - - - - - - - - - - - - - - - - - - - - - - 211 50 I I I ! I 25 I I i I I I I I 0 0 25 50 75 100 125 150 175 200 225 250 GSTABL7 v.2 FSmin=1.570 Safety Factors Are Calculated By GLE (Spencer's) Method (0-2) GSTABL7 ALKA1 Consultants, LLC 9465 Provost Road NW Suite 202 Silverdale, WA 98383 Phone (360) 613-2407 Fax (360) 613-2408 Environmental • Geotechnical Engineering • Wetlands Consulting