基于增量加载法的隧洞上方地基承载力研究

Bearing capacity of foundations above caves based on incremental load method

运用DP系列屈服准则,采用有限差分法求得隧洞地基的极限承载力与潜在滑动面。定义了隧洞地基围岩的局部稳定系数,通过求解局部稳定系数,给出了围岩的稳定范围,对隧洞地基加载前的地层加固提供参考。研究结果表明:极限承载力随剪胀角的增大呈现出先增大后减小的规律,且在剪胀角等于3φ/4时取得极大值,在剪胀角等于摩擦角φ时取得极小值。

Numerical simulation model was established based on the series of DP failure criterion. Bearing capac- ity and potential sliding surface were calculated with incremental load method. The local stability factor of rock foundation with caverns was defined. The maximum value was obtained when dilation angle equals to 3/4 friction angle, and the minimum value was obtained when dilation angle equals to friction angle. The safety range of the rock masses stability was presented, which could give reference for the ground consolidation before loading on the foundation with caverns. The results show that bearing capacity increases at first, then decreases with the in- creasing of dilation angles.