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Home My WebLink AboutTR 31920-1 GEOTECHNICAL REVIEW OF DRAINAGE IMPROVEMENT SoilWorks Earth Sciences Group �. 3130 Airway Avenue C osta Mesa, CA 9:2626 T: 888-544-4164 www.soilworksinc,corn McMillin Land Development September 17, 2010 P.G. Box 85104 Project No, 118-001-01 San Diego, CA 92106 Attention: Senior Vice President Subject: Geotechnical Review of Drainage Improvement And Rough Grading Plans Summerly Drainage Extension, Tract 31920-1 City of Lake Elsinore, Riverside, California References: See attached List of References Dear Mr. Mitchell: Pursuant to the request of of Wilson Mikami Corporation, SoilWorks, Inc. has prepared this report providing our review comments and recommendations on the Summerly Drainage Extension Plans (Reference No. 1) and Rough Grading Plan (Reference No. 2) prepared by Wilson Mikami Corporation. This report incorporates/updates our earlier comments and recommendations presented in our letter dated August 5, 2010 and shall supersede Reference No. 3. Our review is limited to the geotechnical engineering aspects of the project only. The civil and structural engineering design and details, including lines and grades are within the purview of others. SW 'McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No. 118-001-01 And Rough Grading Plans Page 2 of 13 Summerly Drainage Extension Summerly development Lake Elsinore, California Drainage Improvement Plans General The drainage improvement plans (Reference No. 1) show extension of the existing 108" CIPP storm drain pipe, from the intersection of Summerly Place and Hidden Trail, southwesterly along Summerly Place to Diamond Drive. At Diamond Drive, a temporary channel will be constructed, extending westerly through Stage 3 to the golf course. A 54" reinforced concrete pipe (RCP) is planned at the terminus of this channel with outlet to the golf course. This RCP will extend through an existing engineered fill berm bordering the golf course that was placed as part of the Stage 2 mass grading. Temporary Excavations Excavations required to facilitate extension of the CIPP construction along Summerly Place will be on the order of 20 feet deep (maximum) below existing site grades and into the engineered compacted fill placed during the Stage 2 mass grading. Temporary excavations for this CIPP made be made with temporary side slopes at 1 H:1V, or in combination with internal bracing/shoring for the lower portion of excavation. The construction of the RCP at the outfall to the golf course will extend through an engineered compacted fill berm (approximately 30 feet in height) placed during the Stage 2 mass grading. Temporary excavations for RCP installation should be made with sideslopes no steeper than 1H:1V and vertical heights not exceeding 20 feet. Temporary excavations extending greater than 20 feet in vertical height should have sideslopes no steeper than 1.25H:1 V, and/or incorporate internal bracing/shoring for the lower portion with 1H:1V sideslopes maximum 20 feet high above the shored portion. Should the existing fill berm not be immediately reconstructed following RCP installation (i.e., will be reconstructed as part of the Stage 3 mass grading), excavation sideslopes should be laid back to a 2H:1V gradient. SoilWorks Earth Sciences Group McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No. 118-001-01 And Rough Grading Plans Page 3 of 13 Summerly Drainage Extension Summerly Development Lake Elsinore, California All trenches should be shored or sloped back as required by the local regulatory agency, the State of California Division of Industrial Safety Construction Safety Orders, and Federal OSHA requirements. Slope stability analyses substantiating the recommended temporary slope gradients are presented as an attachment to this report. Groundwater The planned invert elevations for the CIPP and RCP will be on the order of 1245 ft. (msl) and 1233 ft (msl), respectively. Available groundwater data reported by Neblett & Associates, Inc. in Reference No. 4 indicates recorded groundwater levels in the vicinity of the planned alignment ranged from approximate Elevation 1234 feet to 1222 feet (msl). Recent preliminary groundwater measurements obtained by our firm in May 2010 at some of these well locations indicate groundwater levels on the order of Elevation 1232 feet to 1227 feet (msl). Based on these groundwater levels and planned pipe invert elevations, the planned depths for the CIIP are generally not expected to intersect groundwater levels. However, the planned RCP invert elevation may be at or in close proximity to the groundwater level. Should groundwater conditions be encountered during excavations at the RCP location, the geotechnical consultant should review the exposed conditions and provide recommendations, as required. Temporary site specific dewatering measures (e.g., sump and pump) may be required to facilitate RCP installation at this location and should be determined on a case-by-case basis. Unsuitable soils, if exposed at the bottom of the excavation, should be over-excavated and replaced with SoilWorks Earth Sciences Group McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No. 118-001-01 And Rough Grading Plans Page 4 of 13 Summerly Drainage Extension Summerly Development Lake Elsinore, California approved materials as recommended in the field and compacted to at least 90 percent relative compaction. Prior to construction of this RCP, it may be beneficial to install appropriately sized groundwater monitoring wells at this location in order to evaluate the existing groundwater levels. These wells would be sized sufficiently to allow for dewatering pumps, if needed. These wells can later serve as dewatering wells, as necessary, to facilitate excavation for and installation and post-construction monitoring of the RCP. ExistingFill II Berm Subdrainage S sy tern The location of planned RCP will cross at or in close proximity to existing subdrainage system installed as part of the engineered compacted fill-over-cut slope (berm) constructed during the mass grading for the Stage 2 development. Rerouting of the subdrainage system and potential groundwater seepage conditions at this location should be anticipated. The location and depth of this subdrainage system at the CIPP crossing should be field located by survey prior to construction. Depending on the location and depth of this existing subdrainage system relative to the CIPP crossing, it may be necessary to construct subdrainage headwalls, cut off structures, and install additional outlet drains such that the existing subdrainage system is neither impeded .or subject to increased water migration and flow, or otherwise cause for adverse groundwater development. In order to mitigate potential adverse seepage and localized groundwater conditions developing from the existing subdrainage system and other sources into the RCP drain backfill, we recommend that the RCP be underlain by a subdrainage system. In the area where the RCP will be in close proximity to the existing fill subdrainage system and waters would be expected to collect, the RCP subdrainage system should consist of two 4-inch diameter Schedule 40 slotted (slot width not exceeding 0.03 inch) PVC well casing (one each running parallel to and on either side of the RCP), and placed SoilWorks Earth Sciences Group McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No. 118-001-01 And Rough Grading Plans Page 5 of 13 Summerly Drainage Extension Summerly Development Lake Elsinore, California on/within (as a portion of) a one foot thick gravel bedding. This subdrainage system should fall in the direction of the endwall, and extend from at least 10 feet distance back from the subdrainage intercept to the endwall structure and discharge via solid pipe through the face of the endwall. The solid pipe sections should extend beyond the endwall face, as appropriate, to facilitate discharge above the ground surface. A schematic detail of this RCP subdrainage system is attached to this report (see Figure 1). Additional details and recommendations addressing this RCP/subdrainage system can be provided based on the exposed conditions. Soil Expansion and Sulfate Corrosion The planned CIPP and RCP storm drain pipe extension will be located within engineered compacted fill placed during the mass grading for the Stage 2 Development. Based on the results of previous laboratory testing performed during the preliminary geotechnical investigation and mass grading for Stage 2 (Reference Nos. 3 and 4), the site soils within the zone of planned CIPP and RCP construction exhibit very low to low soil expansion and negligible sulfate attack to concrete. In an abundance of caution, considerations for long term changes in groundwater and soil chemistry, and to account for localized conditions, differences in import soils and shading materials, etc., we recommend that design be based on moderate soil expansion potential, moderate sulfate exposure to concrete (in accordance with the 1997 UBC Table 19-A-4 and the requirements of the City of Lake Elsinore) and moderate corrosivity to metals. Storm Drain Line Backfill Bedding material should consist of sandy material exhibiting a Sand Equivalent (S.E.) value of 30 or greater and should comply with the requirements of the controlling Soi[Wori<s Earth Sciences Group McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No. 118-001-01 And Rough Grading Plans Page 6 of 13 Summerly Drainage Extension Summerly Development Lake Elsinore, California jurisdiction. The on-site soils may be used for bedding material if they meet the recommended minimum S.E. criterion. The site soils are considered suitable for trench backfill, provided they are free of organic material and rocks over 4-inches in maximum dimension. Approved soils should be placed in thin lifts not exceeding 5-inches and mechanically compacted to achieve a relative compaction of not less than 90 percent based on ASTM: D1557. Care should be taken not to damage the pipeline. Fill Berm Reconstruction Fill materials placed to restore/reconstruct the fill berm should consist of approved on- site materials and be compacted to at least 90 percent relative compaction (ASTM: D1557). Approved materials should be placed in horizontal lifts not exceeding 8+ inches and benched into competent sideslope material. The slope face should be overfilled to an extent determined by the contractor, but not less than 2 feet measured perpendicular to the slope face, so that when trimmed back to finish grade a dense core displaying a minimum 90 percent relative compaction is exposed on the finish slope surface. Compaction of each fill lift should extend out to the temporary slope face. Fill slopes should be backrolled at intervals not exceeding 4 feet. Rough Grading Plan General Planned grading (see Reference No. 2) will include backfilling of the temporary detention basin at the terminus of existing storm drain construction, and temporary minor grading within Stage 3 to facilitate sheet flow drainage to sediment basins bordering and discharging into the channel. SoilWorks Earth Sciences Group McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No. 118-001-01 And Rough Grading Plans Page 7 of 13 Summerly Drainage Extension Summerly Development Lake Elsinore, California Minor Grading and Infilling of Temporary Water Basins The two temporary water basins used during mass grading for the Stage 2 development and located in Stage 3 will be filled with non-engineered fill to provide sheet flow drainage to the swale. These basins should be surveyed by the Project Civil Engineer prior to filling to facilitate re-location and provide spatial limits for removal during later mass grading operations, New fill placements to achieve temporary sheet flow drainage are temporary in nature and are to be removed during future mass grading for Stage 3. As a minimum, approved fill materials should be placed in lifts not exceeding 8± inches and compacted to a firm and unyielding condition at near optimum moisture conditions. Detention Basin The existing detention basin located at the terminus of existing storm drain line "B" should be evacuated of water and over-excavated to remove unsuitable and water damaged soils and expose competent native material. The depth of required removal will be based on the actual soil conditions exposed at the time of grading. The approved bottom should be scarified minimum 6 inches and recompacted to at least 90 percent relative compaction at approximately 2 percentage points wet of optimum moisture contents (ASTM D:1557) prior to backfilling with approved materials. Fill placement should be performed in 8-inch loose lifts, moisture conditioned as necessary, and compacted to the aforementioned percent relative compaction and moisture conditions. Endwalls/ Wingwalls Endwalls/ wingwalls are planned at the CIPP outlet structure and at the terminus of temporary graded channel. These temporary structures should be constructed on approved/suitable native materials or on a horizon of engineered compacted fill. SoilWorks Earth Sciences Group McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No. 118-001-01 And Rough Grading Plans Page 8 of 13 Summerly Drainage Extension Summerly Development Lake Elsinore, California Grading recommendations for the support of these structures will be provided at the time of grading based on the actual soil conditions encountered. It is very important to the long term performance that these structures be well founded in competent ground that is free of hydraulic pathways and pervious zones that can be acted on by adverse seepage development/accumulated trench groundwater. Use of the subdrain system recommended for the RCP outlet area will improve the foundation character and performance of these structures. This improvement will be predominantly in the form of relieving hydrostatic buildup/accumulation. And also help to control adverse seepage and piping underflow/undermining. As previously recommended in the above Soil Expansion and Sulfate Corrosion section, we recommend that design be based on moderate soil expansion potential, moderate sulfate exposure to concrete (in accordance with the 1997 UBC Table 19-A-4 and the requirements of the City of Lake Elsinore) and moderate corrosivity to metals. Observation and Testing Materials testing and inspection of the CIPP pipe should be performed by a qualified materials testing and inspection firm during construction. A representative of our office should be present on-site during site grading to evaluate the acceptability of excavation bottoms, and observe and test the placement of engineered compacted fills. If it is determined during site excavations and grading that deeper earthwork removals and replacement with approved engineered compacted fill are required to provide acceptable support for planned construction and new fill placements, such earthwork should be performed in accordance with the recommendations of our firm. SoilWorks Earth Sciences Group McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No, 118-001-01 And Rough Grading Plans Page 9 of 13 Summerly Drainage Extension Summerly Development Lake Elsinore, California The fill should be tested at the time of placement to verify that the required compaction is achieved. Fill compaction should be determined in the field by Sand cone Method (ASTM: D1556) or Nuclear Gauge Method (ASTM: D2216), or other test method approved by the geotechnical consultant. Relative compaction should be based on the laboratory maximum dry density and optimum moisture content determined in accordance with ASTM: D1557 test procedure. Closure Our review and recommendations provided herein were developed in accordance with generally accepted professional engineering principles and local practice in the field of geotechnical engineering and reflect our best professional judgment. We make no other warranty, either express or implied. SoilWorks Earth Sciences Group McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No. 118-001-01 And Rough Grading Plans Page 10 of 13 Summerly Drainage Extension Summerly Development Lake Elsinore, California This report is subject to review by the controlling authorities for the subject project. If you have any questions or need additional information, please contact the undersigned. Respectfully submitted, SOILWORKS, INC. k D rb By: o _ u, By: _�� n 11NIN0 Dan J. Mo ikawa, P.E. E� z �� rry E. F ni P. .,IC.E.Qo. RGE 276, g, expires ' o C.E.G. 07, g. a pi es 1/��/�Io Chief Engineer 1038 President ��;m, INGINEERING „ GZOLOGIST : 0F CAU'j'' Distribution: Addressee (2) Wilson Mikami Corporation (3 copies) Attachments: List of References Figure 1 — RCP Subdrainage System Detail Appendix A: Slope Stability Analyses File 118-001-01 081710 McMillin Drainage Improvement and Rough Grading Plan Review .doc SoilWorks Earth Sciences Group McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No. 118-001-01 .And Rough Grading Plans Page 11 of 13 Summerly Drainage Extension Summerly Development Lake Elsinore, California LIST OF REFERENCES 1. Wilson Mikami Corporation, Drainage Improvement Plans for Summerly Development, Tract No. 31920-1, City of Lake Elsinore, County of Riverside, State of California, Sheets 1 through 6 of 6, stamp dated September 9, 2010 2. Wilson Mikami Corporation, Rough Grading Plan for Tract 31920-1, Summerly Drainage Extension, City of Lake Elsinore, County of Riverside, State of California„ Sheets 1 through 4 of 4, stamp dated September 9, 2010 3. SoilWorks, Inc., Geotechnical Review of Drainage Plans, Summerly Drainage Extension, Summerly Development, Lake Elsinore, California, revise dated August 5, 2010, Project No. 118-001-01. 4. Neblett & Associates, Inc., Rough Grade Compaction Report, Stage 2 of the Summerly Development Project, Tract 31920, Lake Elsinore, California, dated November 30, 2007, Project No. 420-001-07. 5. Neblett & Associates, Inc., Preliminary Geotechnical Investigation and 40-Scale Grading Plan Review, Tentative Tract 31920, Stage 2 of Summerly Development, City of Lake Elsinore, County of Riverside, California, dated February 7, 2006, , Project No. 420-001-05. 5oilWorks Earth Sciences Group t f I Sect-or Views Not M, SC—cle, V' 1 e,W A 1: Z'.,'Jrl W, - - - - - - - - - - - - - - - - - - - - - -- Cu! -,�f fC-WC (7 f :i d I r-c:K e t ,e t t sr c�v lon IRCP Subdrainage System Detailsi Job No. 118 Surnmerly Development ll-akeElsinorf,, Californi- 1 4� McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No. 118-001-01 And Rough Grading Plans Page 12 of 13 Summerly Drainage Extension Summerly Development Lake Elsinore, California APPENDIX A SLOPE STABILITY ANALYSES SoilWorks Earth Sciences Group McMillin Land Development September 17, 2010 Geotechnical Review of Drainage Improvement Project No, 118-001-01 And Rough Grading Plans Page 13 of 13 Summerly Drainage Extension Summerly Development Lake Elsinore, California SLOPE STABILITY ANALYSES Slope stability analyses were performed along generic sections representing temporary excavation slopes for the CIPP and RCP construction. Shear strength parameters utilized are based on laboratory test results presented in Reference No. 4. Shear values utilized in the slope stability analyses are summarized in Table C-1, TABLE A-1. Summary of Soil Strength Parameters Soil Unit Unit Weight, Cohesion, Cf psf degrees Compacted Fill, (Caf) 130 150 32 The slopes were analyzed by calculating the factors of safety for a circular-type failure using the Modified Bishop's Method using PCSTABL6H, a computer program developed by Purdue University. The results of the slope stability analyses performed are included in this Appendix and are summarized in Table A-2 below: TABLE A-2. Summary of Slope Stability Analyses Cross- Analysis Static F.S. Section CIPP Circular Type, 1 HIV temporary slope, 1.36 20 feet high RCP Circular Type, 1.25HIV temporary 1.35 slope, 30 feet high Based on the results of these stability analyses, the evaluated slopes exhibit factors of safety exceeding minimum 1.25 required for temporary slope conditions, and are acceptable for use during construction. SoilWorks Earth Sciences Group -rJ t� i .zx Lo Cv co P rti i.LZ � �7 C ol %-./ •ri E u., No X co CL L;,m in �, s " to to a. r r -0 Cr y m C W L- in V G r» n _r..+ C.3 0— r.. L1 ..i 6t � tv �-+ 2 Ol .0 "°y`um 'i M � �g 4-1 vs `►- rtl C) O � O r-4 a) E ~ E M .J MA {ir�1 O Ln C) O O N r U1 .,.I X ^ r `e"` ** STABL6H ** by Purdue University --Slope Stability Analysis-- simplified Janbu, Simplified Bishop or Spencer's Method of Slices Run Date: 9/17/2010 Time of Run: 3: 31pm Run By: BHT Input Data Filename: C: 118RCP Output Filename: C: 118RCP.OUT Plotted Output Filename : C: 118RCP.PLT PROBLEM DESCRIPTION Summerly Drainage Extension. 154" RCP, Temp 1 . 25H: 1V backcut BOUNDARY COORDINATES 5 Top Boundaries 5 Total Boundaries Boundary X-Left Y-Left X-Right Y-Right Soil Type No. (ft) (ft) (ft) (ft) Below Bnd 1 100 . 00 130 . 00 120 .00 130 .00 1 2 120 .00 130 .00 157 . 50 100 .00 1 3 157 . 50 100 .00 162 . 50 100. 00 1 4 162. 50 100 . 00 200. 00 130 .00 1 5 200 .00 130 . 00 250 .00 130 . 00 1 -------------------------------------------------------------------------------- ISOTROPIC SOIL PARAMETERS 1 Type (s) of Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. Type Unit Wt . Unit Wt. Intercept Angle Pressure Constant Surface No . (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 130 . 0 130 . 0 150 . 0 32 .0 . 00 . 0 0 -------------------------------------------------------------------------------- 1 PIEZOMETRIC SURFACE (S) HAVE BEEN SPECIFIED Unit Weight of Water = 62 .40 Piezometric Surface No. 1 Specified by 2 Coordinate Points Point X-Water Y•-Water No. (ft) (ft) 1 100 . 00 100 .00 2 220. 00 100 .00 -------------------------------------------------------------------------------- A Critical Failure Surface Searching Method, Using A Random Technique For Generating Circular Surfaces, Has Been Specified. 10000 Trial Surfaces Have Been Generated. 100 Surfaces Initiate From Each Of100 Ports Equally Spaced Along The Ground Surface Between X = 162.50 ft . and X = 175.00 ft . Each Surface Terminates Between X = 200 . 00 ft . and X = 250 . 00 ft. Unless Further Limitations Were Imposed, The Minimum Elevation At Which A Surface Extends Is Y = .00 ft. 10 . 00 ft . Line. Segments Define Each Trial Failure Surface. Restrictions Have Been Imposed Upon The Angle Of Initiation. The Angle Has Been Restricted Between The Angles Of -20. 0 And 45.0 deg. -------------------------------------------------------------------------------- Fol.lowing Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Examined. They Are Ordered - Most Critical First. * * Safety Factors Are Calculated By The Modified Bishop Method Failure Surface Specified By 7 Coordinate Points Paint X-Surf Y-Surf No. (ft) (ft) 1 162. 50 100 .00 2 172. 17 102 .54 3 181 . 33 106. 56 4 189.75 111 .95 5 197. 23 118. 59 6 203.59 126. 31 7 205 .76 130.00 Circle Center At X = 151 . 1 ; Y - 163. 0 and Radius, 64 .1 *** 1 .354 *** Failure Surface Specified By 7 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 162 . 63 100 . 10 2 172 . 34 102 .48 3 181 . 55 106.37 4 190 .03 111 .67 5 '197 . 57 118.25 6 203 .96 125.93 7 206 . 38 130 .00 Circle Center At X = 152 .5 ; Y 162 . 2 and Radius, 62 .9 *** 1 . 357 *** ------------------------------------------------ -------------------------------- Failure Surface Specified By 7 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 162. 50 100 . 00 2 172 . 11 102 .76 3 181 . 16 107 .02 4 189 .40 112 .68 5 196 .63 119 .59 6 202 . 66 127 . 57 7 203 .95 130 . 00 Circle Center At X = 150 .2 ; Y = 161 .0 and Radius, 62.2 ** 1 .360 *** Failure Surface Specified By 7 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 162. 88 100 . 30 2 172. 52 102.95 3 181 .67 107 .00 4 190 .11 112 .36 5 197 . 67 118.90 6 204 . 18 126. 0 7 206 . 37 130 . 00 Circle Center At X = 149.9 ; Y = 166.4 and Radius, 67 .4 *** 1 . 361 ** -------------------------------------------------------------------------------- Failure Surface Specified By 7 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 162 .75 100 .20 2 172 . 56 102.16 3 181 .88 105.78 4 190.45 110 .94 5 198.00 117 .49 6 204.32 125. 24 7 206 .99 130 .00 Circle Center At X = 156. 3 ; Y = 157 .9 and Radius, 58.1 * * 1 .366 Failure Surface Specified By 7 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 162.75 100 . 20 2 172.60 101 .96 3 181 . 93 105.56 4 190.41 110.86 5 197.72 117 .67 6 203 . 61 125.76 7 205.60 130.00 Circle Center At X = 158 .5 ; Y = 152 .4 and Radius, 52 .4 ** 1 .366 ** -------------------------------------------------------------------------------- Failure Surface Specified By 7 Coordinate Paints Point X-Surf Y-Surf No. (ft) (ft) 1 162.63 100. 10 2 172 .49 101 .76 3 181 . 82 105.34 4 190. 26 110.71 5 197 . 47 117.64 6 203. 16 125.86 7 204.93 130 . 00 Circle Center At X 159 .3 ; Y = 150 . 1 and Radius, 50 . 1 *** 1 .368 *** Failure Surface Specified By 7 Coordinate Points Paint X-Surf Y-Surf No. (ft) (ft) 1 163. 51 100.81 2 173 .20 103 . 30 3 182.28 107.47 4 190 .48 113. 20 5 197 .53 120 .29 6 203.21 128 . 52 7 203 . 87 130 . 00 Circle Center At X = 154. 5 ; Y = 156 . 0 and Radius, 56.0 *** 1 .368 *** - ------------------------------------------------------------------------------- Failure Surface Specified By 7 Coordinate Paints Point X-Surf Y-Surf No. (ft) (ft) 1 162 .75 100 .20 2 172 .42 102 .75 3 181 .47 107 .01 4 189.60 112 .84 5 196.53 120 .04 6 202.04 128.39 7 202.73 130 .00 Circle Center At X = 153.7 ; Y 154 .3 and Radius, 54 .9 *** 1 .369 *** Failure Surface Specified By 7 Coordinate Points Paint X-Surf Y-Surf No. (ft) (ft) 1 162. 50 100 .00 2 171 . 99 103 . 14 3 180 . 96 107 .57 4 189.24 113. 18 5 196.65 119.89 6 203.08 127. 55 7 204.61 130.00 Circle Center At X = 144 .6 ; Y = 170 .0 and Radius, 72 . 3 *** 1 .370 *�* ca CL d CL coo CD CL CM a 40 CL x CM m w Ln 4 a a� •• I u G Co i ' co 00 d- c • ++ a, Go 6 /--t -J A 4-+ d dq c X •rw �s w o F- yam.. UJ Awn i° N o [j C cc EU ..a a cp r-i L Qa ww t/�e�if)t] r��fi9Mt�•Sr�ir'lc�"7 �k w ,a a a d W a � •w .., 0 0 0 0 0 0 0 o a N O CO N .w{ X ^ ** STABL6H ** by Purdue University -------------------------------------------------------------------------------- --Slope Stability Analysis-- Simplified Janbu, Simplified Bishop or Spencer's Method of Slices Run Date: 9/17/2010 Time of Run: 3:22pm Run By: BHT Input Data Filename: C: 118C Output Filename: C: 118C.OUT Plotted Output Filename: C: 118C.PLT PROBLEM DESCRIPTION Summerl.y Drainage Extension 108" CIPP, 20 ft Ex. , 1 : 1 Temp Slope BOUNDARY COORDINATES 5 Top Boundaries 5 Total Boundaries Boundary X-Left Y-Left X-Right Y-Right Soil Type No. (ft) (ft) (ft) (ft) Below Bnd 1 100 .00 120 .00 120 . 00 120 .00 1 2 120 .00 120.00 140 .00 100.00 1 3 140 .00 100.00 150 .00 100 . 00 1 4 150 .00 100.00 170. 00 120.00 1 5 170 .00 120 .00 220.00 120 .00 1 -------------------------------------------------------------------------------- ISOTROPIC SOIL .PARAMETERS 1 Type (s) of Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez . Type Unit Wt . Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psi') (deg) Param. (psf) No. 1 130 . 0 130. 0 150. 0 32 . 0 . 00 .0 0 -------------------------------------------------------------------------------- 1 PIEZOMETRIC SURFACE (S) HAVE BEEN SPECIFIED Unit Weight of Water = 62.40 Piezometr,ic Surface No. 1 Specified by 2 Coordinate Points Paint X-Water Y-Water No. (ft) (ft) 1 100 . 00 100 .00 2 220 . 00 100 .00 A Critical Failure Surface Searching Method, Using A Random Technique For Generating Circular Surfaces, Has Been Specified. 10000 Trial Surfaces Have Been Generated. 100 Surfaces Initiate From Each Of100 Points Equally Spaced Along The Ground Surface Between X = 150 . 00 ft . and X = 160. 00 ft. Each Surface Terminates Between X : 170 .00 ft . and X = 220 . 00 ft . I Unless Further Limitations Were Imposed, The Minimum Elevation At Which A Surface Extends Is Y = .00 ft. 8 . 00 ft . Line Segments Define Each Trial Failure Surface. Restrictions Have Been Imposed Upon The Angle Of Initiation. The Angle Has Been Restricted Between The Angles Of -20 .0 And 45.0 deg. --------------------- - -------------------------------------------------------- -- Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Examined. They Are Ordered - Most Critical First. * * Safety Factors Are Calculated By The Modified Bishop Method Failure Surface Specified By 6 Coordinate Points Point X-Surf Y-Surf No . (ft) (ft) 1 150.00 100 . 00 2 157 . 59 102. 53 3 164 .49 106 . 58 4 170.41 111 .96 5 175.09 118. 45 6 175.77 120 . 00 Circle Center At X 141 .7 ; Y = 137 .6 and Radius, 38. 5 *** 1 .361 * Failure Surface Specified By 6 Coordinate Poixbts Point X--Surf Y-Surf No. (ft) (ft) 1 150. 10 100 . 10 2 157 .61 102 .86 3 164.44 107 . 03 4 170 . 32 112.45 5 175. 03 118.92 6 175. 53 120 .00 Circle Center At X = 139 .9 ; Y = 139. 5 and Radius, 40 .7 *** 1 .365 *** ^--_----- Failure Surface Specified By 6 Coordinate Points Point X--Surf Y-Surf No. (ft) (ft) 1 150 .00 100 .00 2 157 . 51 102 .76 3 164. 18 107 . 18 4 169.64 113 . 02 5 173 . 61 119.97 6 173 .62 120 .00 Circle Center At X - 142 .0 ; Y - 133.4 and Radius, 34 .4 *** 1 .368 *** Failure Surface Specified By 6 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 150. 00 100 . 00 2 157 . 53 102 . 71 3 164.43 106 .75 4 170 .49 111 .98 5 175.49 118.22 6 176.43 120 .00 Circle Center At X = 139.1 ; Y = 142 . 2 and Radius, 43.6 * * 1 .368 *** ------------------------------------------------------------------------------- - Failure Surface Specified By 6 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 150.00 100 . 00 2 157 .75 101 .97 3 164 .67 105 .99 4 170 .23 111 .75 5 174.00 118.80 6 174 . 27 120 .00 Circle Center At X = 146.8 ; Y = 128.8 and Radius, 29.0 * * 1 .372 * Failure Surface Specified By 6 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 150 . 30 100.30 2 157 . 76 103. 19 3 164 . 51 107. 0 4 170.27 113.05 5 174.82 119.63 6 174.98 120 . 00 Circle Center At X = 139 .5 ; Y = 139. 2 and Radius, 40 .3 *** 1 . 373 ** -------------------------------------------------------------------------------- Failure Surface Specified By 6 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 150 . 10 100 . 10 2 157 .70 102 . 59 3 164.68 106.51 4 170.75 111 .72 5 175.68 118.02 6 176 . 69 120 .00 Circle Center At X = 141 .3 ; Y = 139 .9 and Radius, 40 .8 *** 1 . 373 *** Failure Surface Specified By 6 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 150. 30 100.30 2 157 .96 102 .62 3 164 .91 106.58 4 170 .80 111 .99 5 175. 34 118 .58 6 175 . 91 120.00 Circle Centex .At X - 143 .9 ; Y = 135.4 and Radius, 35 .7 *** 1 .373 *** -------------------------------------------------------------------------------- Failure Surface Specified By 6 Coordinate Points Point X-Surf Y-Surf No. (ft) (ft) 1 150 .30 100. 30 2 158. 03 102 . 36 3 164. 95 106. 39 4 170 . 56 112. 09 5 174 . 47 119.07 6 174 . 70 120 .00