循环扰动荷载下花岗岩的力学性质与声发射特征参数研究

在工程实际中岩体常常受到循环荷载扰动作用,进而表现出与静态荷载作用下不同的力学性质和声发射现象。因此本文以花岗岩作为试验对象,研究了其在不同循环扰动次数下的力学特性和声发射特征参数,并结合RA、AF值进一步探讨了其在受压过程中裂纹的演化规律。试验表明:试件强度随着循环次数增加而提高,且当循环次数大于一定量时,强度增幅比例开始下降;试件经历的循环次数越多,其在塑性变形时表现出的声发射陡增现象越明显; RA、AF值进一步表明花岗岩在受力至破坏全过程中首先出现剪切破坏事件,在临近峰值强度时,开始出现张拉破坏事件,且主要集中在剪切带周围。

Study on Mechanical Properties and Acoustic Emission characteristic parameters of Granite under cyclic disturbance load

In engineering practice, the rock mass is often subjected to cyclic load disturbance, which shows the different mechanical properties and acoustic emission phenomena under static load. So this article, by studying granite as test object, its mechanical properties under different circulation disturbance frequency and acoustic emission characteristic parameters, and combining the RA value, AF further discusses the evolution regularity of the crack in the process of compression. The test shows that the strength increases with the increase of the number of cycles, and when the number of cycles is greater than a certain amount, the ratio of intensity increase begins to decrease. The more cycles the specimen experiences, the more obvious the sudden increase of acoustic emission in plastic deformation. RA, AF value further show that the granite first appeared in the force to destroy the whole process of shear failure events, near peak intensity, began to appear tension damage events, mainly around the shear zone.