深部巷道围岩变形破坏机制分析

采用弹脆性本构模型以及滑移破坏理论，对深部围岩应力分布以及变形破坏机制进行分析。计算结果表明，开挖卸荷将引起剪应力的增长，滑移剪切变形的发展将围岩划分成具有一定尺度的块体（或条带），它们之间的相互摩擦决定着残余强度的大小；在各向不均匀压缩的作用下，深部围岩能够产生区域拉伸破碎，使围岩开挖断面监测到的位移大大超出按连续介质理论计算得到的数值。采用考虑扩容的计算模型可以得到围岩产生区域拉伸破碎的条件，计算得到的该条件与岩体力学性质以及破碎尺度密切相关。

Analysis of deformation and failure mechanism of surrounding rock for deep underground projects

Brittle constitutive model and slippage destruction theory were used to analyze the stress distribution and failure mechanism of surrounding rock for deep underground project. The result shows that: Excavation unloading will cause the growth of the shear stress, which leading to the local irreversible (plastic) slip or break; and the surrounding rock will be divided into blocks with certain scale; the frictions between the blocks decide the value of the rest strength. Under the action of uneven compression, it can produce zonal tensile breakage, that made the monitored displacement greatly exceed the calculated value with continuum theory. By considering volume expansion, we can get the conditions that cause the tensile breakage; the calculation shows they are related to the material properties and the brocken scale.