棱柱状结构体试件破损过程的试验研究

Experimental study on breaking process of prismatic structural bodies

通过棱柱状结构体在直排、直错排两种排列方式下的平面应变压缩试验,研究了不同侧向应力状态下结构体的破损过程,来探讨结构性岩土材料在受荷过程中的变形和破损机理。试验发现,在棱柱状结构体试件的破损过程中,结构体表现出劈裂、剪切和压碎的破损方式,最后形成破损带;随着侧向应力由低向高的变化,应变软化逐渐向应变硬化过度;低侧向应力状态时应变软化、体胀和侧向挤出;高侧向应力状态时应变硬化、体缩和侧向收缩;不同的侧向应力状态和排列方式下几乎都没有结构体的转动发生。

In order to explain the failure and breakage mechanisms of structural geological materials, the plane strain compression tests of the samples of prismatic structural bodies assembled in two different patterns are conducted under different confining stresses. During the breaking process of structural bodies, it is found experimentally that the main failure modes of structural bodies are splitting, shear failure and crushing, but finally the breakage bands form; while the confining stress increases, strain softening gradually turns to be strain hardening; when the lateral stress is low, strain softening and volume expansion and lateral extrusion can be observed; however, when the lateral stress is high, strain hardening, volume contraction and lateral contraction become prevalent; whatever the confining stress is and which pattem the structural bodies are assembled by, the rotation of the structural bodies is hardly observed.