Abstract：The plane strain compression experiments of the samples assembling of bar-like structural bodies are conducted to study the failure and breakage mechanisms of geological materials. Under different confining pressures，the breaking processes of bar-like structural bodies with two different arrangements are observed. During the breaking process of structural bodies，it is found by experiment that the structural bodies not only slide and rotate，but also break. When the confining stress is small，strain softening，rapid stress drop，volume inflation and lateral extrusion can be observed；while the confining stress is large，strain hardening，volume contraction and lateral intrusion become prevalent.
