土质围岩开挖破坏模式研究

结合大量土质隧道围岩破坏调研资料和室内模型试验，研究土质围岩破坏的位置和形态，以破坏位置和特点探讨了土质围岩的破坏模式，并对各破坏模式进行了定义。研究表明，土质围岩破坏模式有未支护段破坏模式、掌子面破坏模式、未支护段和掌子面同时破坏模式及不发生破坏4种；未支护段破坏模式可分为自稳破坏、进尺破坏和不破坏；未支护段自稳破坏模式主要受洞形跨度和跨高、围岩条件控制，而进尺破坏模式主要受进尺和围岩条件控制；掌子面破坏模式的破坏面可近似为对数螺旋曲面或斜平面，未支护段破坏模式的破坏面可近似为抛物线曲面，未支护段和掌子面同时破坏模式的破坏面近似为数螺旋曲面或斜平面和抛物线曲面相交。

Study of failure modes of soil surrounding rock in excavation

Combining lots of the failure investigations of surrounding rock in soil tunnels and model test, the failure location and state of soil surrounding rock were researched. The failure modes of soil surrounding rock and their definition were discussed according to the failure location and state. The results show that the failure modes of soil surrounding rock include un-supported section failure mode, tunnel face failure mode, the failure mode which un-supported section and tunnel face destroying at the same time and no destroying failure mode. Un-supported section failure mode can be divided into self—stability failure, footage failure and no failure. The main control factors of self-stability are the span and high of tunnel and the condition of soil surrounding rock: but the condition of soil surrounding rock and footage are the primary control factors of footage failure.For tunnel face failure mode,the failure surface shape approximates to logarithmic spiral curve or inclined plane; for un-supported section failure mode, the failure surface shape is a parabolic curve;and intersecting curve of logarithmic spiral curve or inclined plane and parabolic curve for the failure mode which is un-supported section and tunnel face destroying at the same time.