围岩收敛曲线形态对地下结构稳定系数影响分析

针对现代地下支护结构设计方法中缺乏物理意义明确的稳定性表征指标这一不完善之处,结合收敛-约束原理来开展研究.首先,通过选取基于Mohr-Coulomb失效准则的Kastner公式和Duncan公式进行围岩弹塑性分析从而构建围岩收敛曲线;分析各支护单元的力学特性并构建锚喷支护结构支护特征曲线;然后,根据收敛-约束原理和荷载原理导出支护结构的稳定系数,从而建立不同围岩收敛曲线的地下结构稳定性定量评价方法;最后,在各岩体力学参数相似的条件下,通过算例分析不同围岩收敛曲线之间的差异性,展示了不同模式的操作和运行过程.

The Analysis for Stability Coefficient of Underground Structure with the Shapes of Ground Response Curves

To address the deficiencies of new design methods of underground supporting structure, which lacks stability index of definite physical meanings, a study was conducted with the convergence-confinement theory. First the Kastner formula and the Duncan formula based on the Mohr-Coulomb failure criterion were selected to analyze the elastic-plastic of rock to establish ground characteristic curve. Each support unit was analyzed in series to establish the support characteristic curve of bolt-shotcrete support structure. Then, the stability coefficient of the support structure was derived in accordance with the principle of convergence-confinement and the principle of loat, which build up the quantitative evaluation of the stability of underground structure method for different stratigraphic characteristic curves. Finally, the otherness between different ground characteristic curves was demonstrated by other examples under similar conditions for rock mass mechanical parameters. Different modes of operations and operation processes were also shown.