超孔隙水压力作用下某隧洞稳定数值模拟研究

Numerical simulation study of a tunnel stability under excess pore water pressure condition

为研究在超孔隙水压力作用下隧洞开挖支护后围岩的应力应变特性,以某新建取水隧洞为例,采用数值分析法对隧洞的开挖支护过程进行模拟。结果表明:受超孔隙水压力影响,土体开挖将造成隧洞位移逐渐增大,及时支护后变形量得到控制;隧洞围岩剪应力主要分布在拱顶和洞底两侧,支护后剪应力和剪应变均有所减小;在地表车载作用产生超孔隙水压力后,隧洞拱顶右侧所受剪力和弯矩明显大于左侧。

In order to study the effect of excess pore water pressure and tunnel excavation support after supporting of surrounding rock , taking a tunnel as an example, the tunnel excavation process is simulated. The results show that： the soil excavation will cause tunnel displacement increasing gradually, deformation could be controlled with timely support; tunnel surrounding rock shear stress is mainly distributed in both sides of the vault and the bottom of the cave, and the shear stress and shear strain decreases after support; the tunnel shear stress and bending moment is larger than the left significantly when considering the surface vehicle on the right side and with excess pore water pressure.