基于可靠度理论的硐室顶部稳定性研究

Analysis of Cavity Roof Stability Based on Degree of Reliability

基于硐室的顶部破坏模式,考虑地下水的渗透效应,将非线性Mohr-Coulomb破坏准则引入到极限分析中,根据虚功率原理进行了能量耗散计算。考虑岩土参数的不确定性,运用可靠度理论分析了维持硐室顶部稳定所需的支护力;同时分析了周围土体参数对硐室顶部稳定性及维持硐室顶部稳定所需支护力的影响。研究结果表明:孔隙水压力系数和非线性系数越大,维持硐室顶部稳定所需的支护力也越大。同时,土体参数的变异系数也会影响硐室顶部的稳定性,因此建议加强对岩土参数随机性的研究。

Aiming at failure mode of cavity roof,energy dissipation was calculated based on fictitious power principle by introducing Mohr-Coulomb failure criterion into the limit analysis,combined with the consideration of the effect of seepage pressure. Due to the uncertainty of soil properties,degree of reliability was used in the determination of support pressure required to maintain the stability of cavity roof,and effects of surrounding soil properties on the support for maintaining the roof safety were analyzed. Results showed that a higher pore water coefficient and higher nonlinear coefficient can result in greater support pressure required for maintaining the roof stability. It is also found that the coefficient of variation of soil properties will also affect the stability of cavity roof. It is suggested that more research shall be conducted on the uncertainty of soil characteristics.