水压作用对裂隙岩体断裂行为影响研究

Study on the Effect of Hydraulic Pressure on Fracture Behavior of Fractured Rock

摘要: 为研究在地应力场与水压耦合作用下裂隙岩石破坏特性，利用MTS815岩石力学测试系统，并结合柱塞泵水压加载装置，对含有预制裂隙的混凝土试样加载预应力后，进行有无水压作用单轴循环加卸载压缩破坏对比试验。试验结果表明：有水压作用的试件在加载初期便出现初始裂隙，而无水压时试件往往在塑性区或接近塑性区时出现初始裂隙，两者的破坏模式也不相同，在有水压作用时，试件是由于水压引起的表面裂纹扩展而导致破坏，而无水压时则是因为试件内部损伤微裂隙扩展引起的失稳破坏；然而两种条件下的试件强度相差不大，但其破坏过程中产生的耗散能却高于后者。

Abstract: In order to study the failure characteristics of rocks under coupling effect of ground stress field and seepage field, MTS815 rock mechanics test system combined with plunger pump hydraulic loading device are used to load water pressures on concrete samples containing precast crack. After that, uniaxial cyclic loading and unloading compression failure contrast experiments are conducted with the seepage field and without the seepage field. The results show that: specimens with the seepage field present initial crack at the initial stage of loading, but species without seepage field present initial crack always in plastic zone or close to plastic zone. The failure mode under both conditions is not the same. The failure is caused by surface crack expand under the water pressure effects, and without water pressure it is caused by the internal damage and micro cracks extend. The strength under the two kinds of conditions is equivalent, while the dissipated energy in the process of failure is higher than those without seepage field.