STABILITY ANALYSIS OF DEPOSIT LANDSLIDE BASED ON IMPROVED DYNAMIC PROGRAMMING ALGORITHM
SHI Chong1,2,YOU Lin3,XU Weiya1,2,HUANG Wei1,2,ZHANG Yulong1,2
(1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210098,China;2. Geotechnical Research Institute,Hohai University,Nanjing,Jiangsu 210098,China;3. HydroChina Chengdu Engineering Corporation,Chengdu,Sichuan 610072,China)
Abstract:Based on graph theory,investigation of the most dangerous sliding surface and safety coefficient calculation in slope stability analysis is transformed into solution of shortest path problem in mathematics. The dynamic programming algorithm is improved to build a limit equilibrium finite element method(FEM),in which the basic equation is given and the stress along the sliding surface is computed so as to avoid the computing iterative procedure because of given safety coefficient when auxiliary function is introduced. Then the improved method is applied to analyze the stability of landslide deposit at left bank,Xiluodu hydropower station. The safety coefficient is estimated based on the fracture appearance,landslide development and creep deformation under nature condition,then the deformation and failure mechanism is studied. According to monitoring data of hole with clinometer. The sliding surface of limit equilibrium finite element method is compared with reality,so the accuracy of this improved method is verified and stability under rainfall condition is discussed. At last,a analysis procedure is put forward based on limit equilibrium FEM,which is proved more suitable for stability analysis of deposit landslides.
[1] 徐卫亚,周家文,邓俊晔,等. 基于Dijkstra算法的边坡极限平衡有限元分析[J]. 岩土工程学报,2007,29(8):1 159–1 172.(XU Weiya,ZHOU Jiawen,DENG Junye,et al. Slope stability analysis of limit equilibrium finite element method based on the Dijkstra algorithm[J]. Chinese Journal of Geotechnical Engineering,2007,29(8):1 159–1 172.(in Chinese))
[2] BAKER R. Determination of critical slip surface in slope stability computation[J]. International Journal for Numerical and Analytical Methods in Geomechanics,1980,4(4):333–359.
[3] 曹文贵,颜荣贵. 边坡非圆临界滑面确定之动态规划法研究[J]. 岩石力学与工程学报,1995,14(4):320–328.(CAO Wengui,YAN Ronggui. A study on dynamic programming to deteminate noncircular slip surface of slopes[J]. Chinese Journal of Rock Mechanics and Engineering,1995,14(4):320–328.(in Chinese))
[4] PHAM H T V,FREDLUND D G. The application of dynamic programming to slope stability analysis[J]. Canadian Geotechnical Journal,2003,40(4):830–847.
[5] 冯紫良,梁朝霞,戴建国. 复杂受力状态下岩体抗滑移空间稳定性分析[J]. 同济大学学报,2000,28(2):157–161.(FENG Ziliang,LIANG Zhaoxia,DAI Jianguo. Stability analysis of cable bridge anchorage in rock masses[J]. Journal of Tongji University,2000,28(2):157–161.(in Chinese))
[6] 范鹏贤,朱大勇,郭志昆,等. 动态规划法求解边坡安全系数最小上限解[J]. 岩土工程学报,2007,29(3):467–470.(FAN Pengxian,ZHU Dayong,GUO Zhikun,et al. The least upper-bound solution for safety factor of slope by dynamic programming[J]. Chinese Journal of Geotechnical Engineering,2007,29(3):467–470.(in Chinese))
[7] 叶海林,顾宏伟,刘东升. 基于动态规划和随机有限元的边坡可靠性分析[J]. 地下空间与工程学报,2007,3(3):564–567.(YE Hailin,GU Hongwei,LIU Dongsheng. Slope reliability analysis using stochastic FEM with dynamic programming method[J]. Chinese Journal of Underground Space and Engineering,2007,3(3):564–567.(in Chinese))
[8] 吴海真,顾冲时. 联合运用改进的极限平衡法和动态规划法分析边坡稳定性[J]. 水利学报,2007,38(10):1 271–1 277.(WU Haizhen,GU Chongshi. Slope stability analysis using enhanced limit equilibrium method combined with dynamic programming[J]. Journal of Hydraulic Engineering,2007,38(10):1 271–1 277.(in Chinese))
[9] 陈云敏,李育超,凌道盛. 蒙特卡洛法与有限元结合搜索边坡临界滑动面[J]. 岩土力学,2004,25(增2):75–80.(CHEN Yunmin,LI Yuchao,LING Daosheng. Locating sritical slip surfaces by a method combining monte carlo technique and FEM[J]. Rock and Soil Mechanics,2004,25(Supp.2):75–80.(in Chinese))
[10] CHENG Y M. Location of critical failure surface and some further studies on slope stability analysis[J]. Computers and Geotechnics,2003,30(3):255–267.
[11] GOH A T C. Genetic algorithm search for critical slip surface in multiple edge stability analysis[J]. Canadian Geotechnical Jamal,1999,36(2):382–391.
[12] DONALD I B,CHEN Z Y. Slope stability analysis by upper bound approach:fundamentals and methods[J]. Canadian Geotechnical Journal,1997,34(6):853–862.
[13] 夏健明. 四结点单元应力云图的一种生成方法[J]. 计算机工程与设计,2004,25(5):844–845.(XIA Jianming. Method for forming stress nephogram of four-node elements[J]. Computer Engineering and Design,2004,25(5):844–845.(in Chinese))