裂面优化法在岩土及隧道工程中的应用研究

Applications and researches of discontinuity layout optimization method in geotechnical and tunneling engineering

裂面优化法是一种2007年提出的新颖的极限上限分析方法,提出后广泛应用于岩土甚至板壳结构的极限与稳定性分析。裂面优化法在结构体内部和表面设置大量散点,将散点连成的线(二维)和面(三维)作为潜在滑移面。基于弥散能最小化原理,引入优化目标方程,并将几何兼容条件、摩尔-库仑条件、荷载/做功条件等已知信息作为优化方程的约束,求解获得极限荷载/安全系数,并得到对应的滑移面分布与张开量。方法概念清晰,前后处理方便,计算效率极高,然而目前该方法在国内的相关研究和应用较少。本研究是第一篇系统介绍裂面优化法的中文文献,对于裂面优化的基本概念及应用,尤其是在隧道工程中的应用进行详细介绍,有助于该方法在国内的进一步推广和发展。

The discontinuity layout optimization is a novel numerical method for upper bound limit analyses,proposed in2007.It is widely used in analyzing the limit load and stability of geotechnical and plate/shell-like structures.In this method,a large number of nodes are introduced into the domain,the lines(2 D)and surfaces(3 D)formed by the nodes are considered as potential discontinuities.Based on the minimization of dissipated energy,the target function is built.The restraints equations are generated by geometric compatibility conditions,Mohr-Coulomb flow rules,and load/work conditions.Not only the limit load/factor of safety but also the activated discontinuities and displacement jumps are obtained.The method is theoretically clear,whose pre-and post-processing is easy for implementing and its computational efficiency is very high.However,there are only a few researches and applications about this method in China.This work is the first Chinese paper introducing DLO,which presents basic concepts,engineering applications especially in geotechnical and tunneling engineering of this method in details,which will hopefully promote its further developments in China.