软岩扩容性对巷道围岩特性曲线的影响

EFFECT OF DILATANCY OF SOFT ROCKS ON ROCK CHARACTERISTIC CURVES OF TUNNELS

放弃了传统的围岩体积不变假设，采用非相关联塑性流动法则模拟软岩的塑性扩容特性，推导了一个新的塑性区位移理论解，并以该位移理论解为基础，分析了软岩巷道围岩的膨胀特性与扩容现象，详细讨论了软岩塑性膨胀对巷道围岩的位移分布规律和特性曲线的影响，得出软岩的膨胀性只对塑性区位移分布规律有影响，而与弹性区位移分布无关；巷道位移随膨胀角的增大而增大等重要结论．

The traditional assumption that the volume of rock mass does not change is given up, and the rule of non associative plastic flow is applied to simulate the plastic dilatation of soft rocks. A new theoretical solution for displacement in plastic zone is deducted. Based on this new solution, the volumetric dilatation of soft rocks around the tunnels is analyzed in details. Effects of plastic dilatation on displacement distribution and ground characteric curves are also discussed. Some important conclusions have been drawn, such as that dilatancy of soft rock will affect displacement distribution only in the plastic zone, but not in the elastic zone; and that the displacement around the tunnel increases with the increase of dilatant angle.