孔隙水作用下浅埋圆形隧道支护反力上限计算

Upper-bound Calculation of Supporting Force for Shallow Circular Tunnels Considering Pore-water Pressure

浅埋隧道的支护反力的确定是控制隧道围岩稳定性的关键,针对浅埋圆形隧道,基于极限分析上限定理和一定的假设,考虑了孔隙水压力作用,计算了内能耗散和外力功率,得到了孔隙水压力作用下浅埋圆形隧道的支护反力的上限解,将浅埋圆形隧道的支护反力求解转化成一个数学优化问题,并利用MATLAB编制相应计算程序。计算结果表明:埋深H、内摩擦角φ、洞径h、孔隙水压力系数λ都对浅埋圆形隧道的支护力有很大的影响。

The determination of supporting force is the key to maintain the stability of shallow tunnels. Based on limit analysis theorems as well as certain assumptions, shallow circular tunnels are studied in this paper,. Considering the pore water pressure, the internal energy dissipation and external power are computed to obtain the upper-bound solution of supporting force for shallow circular tunnels subjected to the pore-water pressure. The supporting force of shallow tunnels has been transformed into a mathematic optimization problem and the corresponding computer program is coded using MATLAB. The results show that： the buried depth H, internal friction angle φ, the diameter h and pore-water pressure coefficient λ. have a great impact on the supporting force.