Study On Microseismic And Charge Induced Signals During Deformation And Failure Of Pre-cracked Rock

The cracks in the rock have an important influence on the mechanical properties of the rock,increasing the probability of disasters in mining,underground tunnels,water conservancy and hydropower projects.Using microseismic and charge-induced signals generated during deformation and failure of pre-cracked rock to predict and forecast the disaster in time and take corresponding measures to reduce the occurrence of disasters.Microseismic and charge-induced signals can reflect the stress changes of pre-cracked rock from multiple angles,improve the capture capacity of the monitoring system,and increase the accuracy of prediction and prediction.In this paper,the physical test is the main research method,and the microseismic and charge induction monitoring system for the pre-cracked rock failure process is established.The variation of microseismic and charge-induced signals under different uniaxial compression conditions for different angle pre-cracks,different loading rates and different types of pre-cracked rocks were studied.The results show that at the same loading rate,the complete rock sample and the 0° pre-cracked rock sample undergo splitting failure,and the 90° pre-cracked rock sample is crushed and destroyed,and the pre-fabricated inclination angle is reduced from 60°?45°?30°.Small,the rock sample is transformed from shear-shear composite failure to shear-slip failure,and the peak stress of the rock sample is reduced.As the pre-fabricated tilt angle decreases,the time for the first occurrence of high-value microseismic and charge-induced signals is gradually advanced.Under different loading rates,with the increase of loading rate,the rate of accumulated deformation energy of pre-cracked rock samples is accelerated,the process of stress adjustment is advanced,and the uniaxial compressive strength of pre-cracked rock is enhanced.In different kinds of prefabricated cracked rocks,the number of microseismic and charge-induced signal events and signal intensity increase during the deformation and failure of pre-cracked rock with the increase of rock strength.The frequency of microseismic and charge-sensing signals during the deformation and failure of pre-cracked sandstone and pre-cracked granite are below 200 Hz.The pre-cracked sandstone microseismic signals are mainly concentrated at 0-80 Hz,and the pre-cracked granite microseismic signals are mainly concentrated at 0-40 Hz.The charge-induced signal has several dominant frequencies,and the dominant frequencies of the two rocks are not exactly the same.This paper has 39 figures,3 tables and 91 references.