基于H-B破坏准则的浅埋硐室顶部围岩塌落面分析

Analysis on Surrounding Rock Collapse on the Top of Shallow Buried Chamber Based on Hoek-Brown Failure Criterion

基于Hoek-Brown非线性强度破坏准则,构建了二维任意几何对称截面浅埋硐室顶部围岩破坏机制;根据极限分析上限定理,通过计算内能耗散功率和外力功率构建了目标函数;利用变分法对目标函数进行极值求解,推导出极限状态下任意几何对称截面硐室塌落形状的函数表达式;运用Matlab软件求解并分析出各参数对塌落范围以及形状的影响,同时利用CAD绘制相应的二维塌落形状图。

Based on the Hoek-Brown nonlinear strength failure criterion,the failure mechanism of the surrounding rock on the top of the shallow buried chamber with two-dimensional arbitrary geometrical symmetry section was constructed.According to the upper bound theorem of limit analysis,the objective function is established by calculating the internal energy dissipation power and the external force power.The calculus of variations was used to solve the extremum of the objective function and the function expression for the collapse shape of the chamber with arbitrary geometrical symmetry section was derived in the limit state.By means of Matlab,the influence of each parameter on the collapse range and shape is solved and analyzed,furthermore,the corresponding two-dimensional collapse shape graph is drawn with CAD.