共线裂纹在三轴压缩下断裂破坏特征的试验研究及数值分析

Experimental study on the fracture property of collinear cracks under true triaxial compression

采用真三轴加载装置,试验研究了共线裂纹倾角和侧压力对试件强度和裂纹扩展规律的影响。试验所用材料为水泥砂浆,试件为带有预制贯穿共线裂纹的方形平板。同时为了定性地解释试验结果,采用了ABAQUS软件进行了数值模拟研究,试验和数值模拟结果相吻合。研究结果表明:裂纹倾角对于试件的强度有显著影响,大约在45°时其强度最低;围压对于试件的抗压强度具有显著的影响作用,其抗压强度随着围压的增大而增大,在低围压作用下次生裂纹从原始预制裂纹的尖端以较大的起裂角开始扩展,而高围压下裂纹的扩展更容易以平行于轴方向扩展。

Experimental study on the fracture property of three collinear cracks concrete specimens under compression was implemented by using a uniaxial loading system and a self-made lateral loading device.The specimens were a square plate and made of cement ,sand and water.The relations of fracture property for the specimens with different crack orientation and the lateral confining stress were investigated. At the same time,in order to explain the experimental result qualitatively,numerical simulation technology based on ABAQUS was used, the simulation results are in accord with the experimental results.The results showed that the crack angle had a great influence on the strength,which was the lowest when the crack angle was approximately;the confining pressure had significant influence on the compressive strength of specimens,the compressive strength increased with confining pressure,under low confining pressure next crack from the original crack tip with a large angle of crack initiation and propagation began to expand ,crack under high confining pressure more easily in parallel in the axial direction of expansion.