某矿深部灰岩蠕变声发射试验与特性研究

Experimental Study on Acoustic Emission Characteristics of the Creep Deformation of the Deep Limestone of a Mine

对某矿深部灰岩进行了蠕变声发射试验,研究灰岩在不同应力水平状态下的蠕变声发射特征。结果表明:声发射参量在恒载初期变化较活跃,灰岩的泊松比也有较大波动;进入长期恒载蠕变阶段后,声发射参量和灰岩的泊松比波动较小;当加载应力达到灰岩单轴抗压强度的90%左右时,灰岩的声发射特征参量出现突增现象。根据声发射参量的变化以及灰岩在不同蠕变阶段的应变特征,在一定程度上可对灰岩蠕变破坏进行有效预测。

The acoustic emission test of the deep limestone creep deformation of the mine is conduc- ted, so as to study the acoustic emission characteristics of the creep deformation of limestone under differ- ent stress level conditions. The study results show that in the early stage of permanent loading, the varia- tion of acoustic emission parameters is relatively active,Possion ratio of limestone also fluctuates greatly; after entering the stage of long-term constant creep deformation ,acoustic emission parameters and Possion ratio of limestone fluctuate less;when the loading stress reaches about 90% of the uniaxial compressive strength of limestone, surge phenomenon of the acoustic emission parameters of limestone is appeared. The above study results further show that according to the variation characteristics of acoustic emission param- eters and the strain characteristics of limestone in different creep deformation stages, the creep failure of limestone can be predicted to a certain extent.