Numerical Simulation Of Acoustic Emission During Rock Failure

Since the sound emission phenomenon was discovered in the early last century,acoustic emission technology and related theory has played an important role in many areas after several generations of experts’ and scholars’ continuous improvement.In recent years,all kinds of large-scale geotechnical engineering at home and abroad gradually rises.On the other hand,geological disasters related to the geotechnical engineering are frequently happening.Whether it is landslide,deformation,or rock burst,landslips,it will be a serious threat to people’s life and the property safety.Rock is the material basis of the crust,which is a typical quasi-brittle engineering material.Its main properties are heterogeneity and discontinuity.It is its complex mechanical properties that cause the complex evolution in the process of failure.The acoustic emission phenomenon was caused by the rock during the process of destruction that is the process of deformation or fracture of the rock material after the action of the rock.And the internal energy is released in the form of elastic waves,which can measure the stability of the mechanical structure of the rock material.Based on the acoustic emission technique,this paper took red sandstone and marble as experimental objects.The rock deformation and failure process is obtained by using the parameters of rock acoustic emission ringing,the cumulative number of acoustic emission and the absolute energy release rate,which established the intrinsic relation between acoustic emission characteristics and deformation process so as to provide a test basis for studying the damage and the failure mechanism of rock and rock materials.This test explored the characteristics of stress and acoustic emission parameters of red sandstone and marble under uniaxial compression and confining pressure.The result shows that the brittleness of the marble is more obvious than the red sandstone,and the acoustic emission events are different under the confining pressure.The numerical simulation for the acoustic emission during the rock fractures process is carried out.The heterogeneity coefficient is introduced in the numerical model.As for the red sandstone samples,the acoustic emission events are more concentrated with the increase of the heterogeneity coefficient after the peak stress in the time series.In the spatial sequence,the acoustic emission events are more concentrated while the corresponding macroscopic phenomena are more obvious.In terms of the marble samples,the acoustic emission events do not differ greatly in the time series with the increase of the heterogeneity coefficient.However,in the spatial sequence,with the increase of the heterogeneity coefficient,the location of the acoustic emission events is more concentrated,which constitutes the main rupture zone.At the same time,the effects of different homogeneity coefficients on the acoustic emission of rock were investigated under different confining pressures.Obviously,both of them had a significant effect on the acoustic emission events.The application range of the rock acoustic emission technology expands throughthe numerical simulation of the acoustic emission of the rock material by the acoustic emission test and the virtual key model.Meanwhile,the virtual internal key model provides a new idea for the study of the acoustic emission phenomenon of rock as well as deepens the understanding of the acoustic emission phenomenon of rocks,and the study of rock mechanics engineering also plays a significant role on theory and practice.