中文摘要：

通过棱柱状结构体在不同排列方式下的平面应变压缩试验，研究了侧向应力卸载状态下结构体的破损过程，探讨了结构性岩土材料在卸侧向应力状态下的变形和破损机理。试验发现，在侧向应力卸载的过程中，棱柱状结构体会发生错动和结构体的破碎，结构体的破损方式主要有劈裂破坏和剪切开裂两种。结构体试样逐渐破损，宏观上出现应变硬化或应变软化现象，最后形成宏观的破损带。试件的总体体积是收缩的，侧向变形则由收缩逐渐转化为膨胀。

英文摘要：

In order to explain the failure and breakage mechanisms of structural geological materials ,the plane strain compression tests of the samples of prism-like structural bodies assembled in three patterns are conducted under unloading conditions. In the process of reducing the lateral stress, it is found experimentally that the structural bodies will be broken after some relative movement and the main failure modes of structural bodies are splitting and shear failure; while the samples assembling of prism-like structural bodies are broken gradually, the strain hardening or strain softening can be observed and breakage bands are macroscopically formed in the end; the volume strain of the samples is always contractive but the lateral contractive strain turns to be the lateral extensive gradually.