论文部分内容阅读
在基于电检测的岩体动力灾害预测预报技术中,分析岩石的变形破裂状态与电信号的相关性是关键环节。采用自行研制的岩石电荷感应试验系统,对花岗岩和煤岩试样进行单轴加载条件下的电荷感应检测,分析了岩石峰前阶段变形破坏状态与电荷感应的相关性。结果表明,电荷感应信号在不同的变形破坏阶段呈现出明显特征,电荷感应信号可反映岩石内部结构的变化,变形破坏过程与电荷感应规律有良好的相关性。对花岗岩试样而言,压密段电荷感应信号的幅值较小且分布最零散,弹性段没有明显的电荷感应现象,稳定变形段电荷感应信号的幅值中等且分布密集,加速变形段部分电荷感应信号的幅值最大且再次呈现出密集分布的状态。对煤岩试样来说,加速变形阶段的电荷感应信号与花岗岩存在较大差异,电荷感应信号的幅值明显增大,正电荷的数量明显增多且信号更为集中,二次加载阶段的变形过程一直伴随感应电荷产生,信号幅值集中在±500 mV的范围内,不但幅值大大减小,正电荷出现的次数也明显增多。结合岩石单轴压缩内部裂纹形成机制和变形阶段划分的研究成果,采用电荷感应信号可分析和评判岩石所处的变形破坏状态。
In the technology of predicting and predicting rock mass dynamic disasters based on electrical detection, it is a key link to analyze the correlation between deformation and rupture of rocks and electrical signals. A self-developed rock charge induction test system was used to test the charge induction of granite and coal rock under uniaxial loading. The correlation between deformation and damage state and charge induction at the pre-peak stage was analyzed. The results show that the charge-induced signal shows obvious features in different stages of deformation and failure. The charge-induced signal can reflect the change of the internal structure of the rock. The deformation and damage process have a good correlation with the charge-induced law. For the granite samples, the amplitude of the charge-induced signal in the compact section is small and the distribution is the most scattered, the elastic section has no obvious charge induction phenomenon, and the magnitude of the charge sensing signal in the stable deformation section is medium and densely distributed. The amplitude of the charge-sensing signal is maximum and once again presents a densely distributed state. For coal and rock samples, charge-induced signals in the accelerated deformation stage are quite different from those in granite. The amplitude of the charge-induced signal is obviously increased, the number of positive charges is obviously increased and the signal is more concentrated. The deformation in the secondary loading stage The process has been accompanied by the generation of an induced charge. The signal amplitude is concentrated within a range of ± 500 mV. Not only the amplitude is greatly reduced, but also the number of positive charges is significantly increased. Based on the research results of the formation mechanism of uniaxial compressive cracks in the rock and the division of deformation phases, the charge-induced signal can be used to analyze and evaluate the deformation and failure state of the rock.