岩石点荷载作用下对应力记忆效应的声发射数值模拟与试验研究

 在分析单轴压缩试验岩石Kaiser效应机制的基础上，建立岩石在点荷载作用下对先前应力记忆效应的理论表达式，采用岩石破裂过程分析软件RFPA2D对14种不同尺寸和力学参数的试件进行数值模拟，模拟结果表明，岩石点荷载声发射试验能够反映岩石先前应力状态，点荷载加压出现声发射时的点荷载值与岩石先前所受应力值成正相关关系。为了进一步验证上述结论，对5个岩石试件进行单轴压缩加载、卸载后用点荷载重新加载的循环试验，得到与数值模拟相同的结论，研究成果为工程现场地应力值估算、评价提供新的研究方法。

EXPERIMENTAL RESEARCH AND NUMERICAL SIMULATION OF ACOUSTIC EMISSION OF MEMORY EFFECT OF ROCK STRESS UNDER POINT LOAD

Theoretical expression of memory effect of previous stress under point load is established based on damage mechanics of Kaiser effect in uniaxial compression. Fourteen specimens with different parameters of mechanical properties and different ratios of height to width are given to simulate memorizing ability of previous stresses in rock specimens under point load using software of RFPA2D(rock failure process analysis). The results show that the value of point load on specimens increases with the increase of previous stresses in rock specimens when acoustic emission occurs. In order to further verify the results obtained from numerical simulation，acoustic emission experiments of 5 specimens under loading and unloading of uniaxial compression and point loading are conducted. The experimental results agree well with those of numerical simulation. It provides a new method for the estimation and assessment of in-situ stress.