Limit step length iteration method in finite element reliability analysis of slope stability

作者：Tan Xiaohui^*; Wang Jianguo; Wu Linian; Cui Kerui; Chu Chengfu

来源：Chinese Journal of Rock Mechanics and Engineering, 2007, 26(SUPPL. 1): 2901-2906.

• Aitken
• Design point method
• Incremental tangent stiffness method
• Limit step length iteration method (LSLIM)
• Mohr Coulomb yield criterion
• Partial differential method
• Reliability index
• Slip surface
• Slope engineering

Design point method, in which the iterative calculation is needed to computer the reliability index, is usually used for first-order reliability analysis of slope. However, there exist some cases when the iteration procedure is not covered in the design point method, since the limit state function is often highly nonlinear in the finite element reliability analysis. Therefore, limit step length iteration method (LSLIM), which is used in the structural reliability analysis, is adopted to perform the reliability analysis of slope stability; and the methods to determine the initial step length and step adjusting coefficient are discussed. As to the calculation of reliability index, the method based on the technique of sliding surface stress analysis and the elastoplastic finite element theory is adopted. The type of the limit state function is set up according to the Mohr-Coulomb yield criterion which can consider the direction of the slip surface; and the derivatives of the stress to the basic stochastic variables of the slope are computed by using partial differential method based on the incremental tangent stiffness method and the accelerating convergence method of Aitken. The overall reliability index is defined as the smallest one of the whole possible sliding surfaces. Analysis results demonstrate that it is feasible to use LSLIM in the finite element reliability analysis of slope stability. LSLIM can assure the convergence of the iteration of reliability index even when the limit state function is highly nonlinear.

• 出版日期2007
• 单位合肥工业大学