11 25 stable state. These conclusions were basically consistent with the analysis results of the multi - stage landslide in loess area with the Monte

211 11 11 158 JOURNAL OF RAILWAY ENGINEERING SOCIETY Nov 211 NO. 11 Ser. 158 16-216 211 11-24 - 6 1 2 3 3 3 1. 126 2. 92181 74 3. 181 1 2 3 4 1. 27 1. 3 1. 56 1. 73 4 1 2 3 4. 96 1. 15 1. 48 1. 6 f s = 1. 2 1 2 1. 15 3 4 1. 2 P694 A Analysis and Research on 3D Simulation for Stability of Xiayahe Multi - stage Landslide HE Shu - jun 1 LIU Jing - ru 2 WU Shu - ren 3 ZHANG Chun - shan 3 YE Si - yuan 3 1. China Zhonghua Geotechnical Engineering Co. Ltd Beijing 126 China 2. Unit 92181 People's Liberation Army of China Gaobeidian Hebei 74 China 3. Chinese Academy of Geological Sciences Beijing 181 China Abstract Research purposes In order to reproduce the processes and the formation of Xiayahe landslide the 3D geological simulation analysis for Xiayahe landslide was made and the simulation result was compared to the analysis result of the stability of the multiple - stage landslide in loess area with the Monte - Carlo simulating method. Research conclusions The research results showed that in natural state the simulated safety factors of the sliding surface of the 1 2 3 and 4 stages were respectively 1. 27 1. 3 1. 56 and 1. 73 and it indicated that the instability would not appear to the four sliding surfaces in a given sliding surface spatial form and in the natural geotechnical parameters conditions. The simulated safety factors of the sliding surface of the 1 2 3 and 4 stages were respectively. 96 1. 15 1. 48 and 1. 6 when the simulation calculation was made for the geotechnical parameters in the saturation state. If the safety factor fs = 1. 2 was taken as the critical value it showed in the saturation state the obvious instability phenomenon appeared to the1 - stage sliding surface the safety factor of the 2 - stage sliding surface was 1. 15 being at the edge of instability and the safety factor of the 3 and 4 - stage sliding surfaces was bigger than 1. 2 being in the 211-5 - 2 NO. 26BAC4B5 28BAK47B4 No. 211. 1. 1974

11 25 stable state. These conclusions were basically consistent with the analysis results of the multi - stage landslide in loess area with the Monte - Carlo simulating method. Key words Xiayahe landslide 3D stability simulation strength reduction method Molar - Coulomb Criterion finite element method 8 ~ 12 m 2 ~ 25 ANSYS FLAC 1-2 9 m 2 322 1 1-2 2 3 1 1 1 4-5 c φ ANSYS MSC MARC D - P F = αi 1 + 槡 J2 = k 1 I 1

26 211 11 J 2 τ α k φ c τ = σ 1 - σ 2 sin2α + τ α k π 2 xy cos2α 3 F 3 1 π 1 α k DP1 DP2 2sinφ 槡 3 3 - sinφ 2sinφ 槡 3 3 + sinφ DP3 sinφ 槡 3 槡 3 + sin 2 φ 2 DP4 槡 3sinφ 槡 2 槡 3π 9 - sin 2 φ 6ccosφ 槡 3 3 - sinφ 6ccosφ 槡 3 3 + sinφ 3ccosφ 槡 3 槡 3 + sin 2 φ 6 槡 3ccosφ 槡 2 槡 3π 9 - sin 2 φ FLAC - σ 1 = 1 + sinφ 1 - sinφ σ 3-2c 1 + sinφ 1 - sinφ 槡 2 σ 1 σ 3 F F - 8 1 2 Spencer DP4 F FLAC σ = σ 1 + σ 2 2 + σ 1 - σ 2 cos2α - τ 2 xy sin2α - 3 l l c + σtgφ ds F = l τds 4 5 c + σtgφ ds l τds F σ σ 1 σ 2 τ τ xy c φ α 5 F l c F + σtgφ F ds 1 = l τds 6 l c' + σtgφ' ds 1 = l τds c' = c tgφ tgφ' = F F 6 7 8 6 3 2 3. 1 1 2 3 4 3 4 5 σ 2

11 27 2 γ / kn /m 3 ν K /MPa G /MPa E /MPa φ c /kpa 2. 2 22 9 25. 31 14. 3 22. 6 23. 6 22 7 2. 35 9. 8 12. 8 2. 4 23 1 28. 3 15. 5 2. 7 23. 3 22 8 22. 33 9. 6 18. 6 22. 7 24 12 3. 29 17. 8 28. 9 22. 4 26 13 34. 28 16. 7 33. 4 3. 2 4 4 X 55 m Y 3 m Z 71 m 846 m 5 18 519 S3 1 599 S1 X S2 S3 Y 3. 3 5 ~ 14-2 ~ -. 4 MPa S1 S2 1 2 3 4 1. 27 S1-1. 1 ~. 1 MPa S2 1. 3 1. 56 1. 73-1. 2 ~ MPa 4 1 2 5 ~ 1 2 8 1 2 3 4. 96 1. 15 1. 48 1. 6 f s = 1. 2 1 1 2 2 1. 15 1 3 4 3 4 1. 2 3 4

28 211 11 9 13 14 1 9 ~ 14 1 1

11 29 1. J. 28 11 1822-1831. He Shujun Zhang Chunshan Wu Shuren etc. Reliability Analysis of the Multi - layer Landslide in Loess Based on the Monte - Carlo Simulating Method J. Geological Bulletin of China 28 11 1822-1831. 2. J. 29 8 164-176. He Shujun Zhang Chunshan Chen Zhihua etc. Risk Evaluation for the Xiayahe Landslide in Weibin Districtt of Baoji City in Shanxi Province J. Geological Bulletin of China 29 8 164-176. 3. M.. 1999. Cheng Qiangong Peng Jianbing. Highspeed Rockslide Dynamic M. Chengdu Southwest Jiaotong University 4 Press 1999. 1 4. Sarma J. 211 7 21-27. Jiang Shuihua Li Dianqing. Analysis of Reliability of Slope Stability with Stochastic Response Surface Method and Sarma Method J. Journal of Railway Engineering Society 211 7 21-27. 2 5. K 22 + ~ + 22 1 2 3 4 1. 27 1. 3 1. 56 J. 211 7 42-47. 1. 73 Song Xiangjun. Landslide Characteristics and Control 4 Countermeasures between K 22 + ~ + 22 Section 1 2 3 4 along Shi - Zhong Highway J. Journal of Railway. 96 1. 15 1. 48 1. 6 Engineering Society 211 7 42-47. f s = 1. 2 1 6. D. 2 1. 15. 29. 3 4 1. 2 He Shujun. Study on Geo - hazard Risk Assessment in Weibin District of Baoji City in Shanxi Province D. 3 1 Beijing Chinese Academy of Geological Sciences 29.