基于FLAC平台的岩体边坡渐进破坏模拟分析

岩体边坡的强度不均匀性和局部应力集中是客观存在的,破坏往往产生于薄弱部位,而后逐渐发展造成岩体边坡的整体失稳。应用岩土分析软件FLAC~(3D)的单元力学参数赋值、单元破坏状态查询等FISH语言函数,编制了单元初始随机强度赋值与峰后残余强度置换的FISH语言程序,实现岩体边坡渐进破坏的FLAC~(3D)模拟。以大孤山露天矿东南帮边坡为工程背景建立了模拟计算简化模型,在-450 m水平开挖形成最终边坡体时有少量坡脚单元出现了塑性流动破坏,但不同强度随机样本边坡的数量和位置则有所不同,按传统评价方法可以判定边坡是稳定的。将进入塑性流动状态的单元置为残余强度后继续进行模拟计算,则坡脚破坏区逐渐增大,最后发展为边坡整体失稳。因此数值模拟时考虑岩体的强度随机性及峰后残余强度是非常必要的,岩体边坡的渐近性破坏模拟分析更贴近客观实际。

Simulation Analysis of Rock Slope Progressive Failure Based on FLAC

The strength inhomogeneity and local stress concentration of rock slope are existed objectively,The failure of rock mass slope is often produced in weak parts,and then gradually developed to instability as a whole. The element parameter assignment function and element plasticity status query function of FISH language of geotechnical analysis software FLAC3D are adopted to compile the FISH language program about element initial random assignment and the residual strength replacement, to use the FLAC3D software to simulate the progressive failure of rock mass slope. The simplified simulation model Is established in the engineering background of the southeast slope of Dagushan open-pit mine,after the final 450 m level excavation,there is a small amount of element failure in slope toe parts,but the plastic flow element number and position is different for different random sample slope. According to the traditional evaluation method,the slope can be determined to stable. In the further simu-lation after element residual strength replacement for plastic flow element,the slope failure zone is increased gradually,and fi-nally whole slope instability. Therefore,it is necessary to conduct simulation analysis by considering the randomness and residu-al strength of rock mass. The simulation results of progressive behavior of rock mass is close to the reality.