Mechanical model establishment and energy characteristics analysis for rock material considering the dynamic disturbance effect

Abstract

Abstract An element mechanical assembly model was established with the combined modeling method to study the dynamic damage behaviors of deep rock. In this model, the effect of disturbance and pre-static loading on the rock mechanics and statistical parameters was considered and a modified function was introduced to deduce the damage evolution function, thus a mechanical model of rock was established. This model was verified against the relevant experimental and bibliographic data. The results show that the damage evolution rate curve gradually moves to the right along the strain axis and the peak value of curve decreases first and then increases with increasing parameter k. When k is large, the damage evolution rate appears a “plateau” which is more obvious as k gets higher. This “plateau” may correspond to the damage stable development stage. Further, the pre-static loading can improve the resistance to impact of rock. The released energy of rock in the rebound under pre-static loading is higher than that under no pre-static loading with the constant disturbance frequency. It decreases with disturbance numbers rising as the pre-static loading remains unchanged, which indicates the resistance to impact of rock is weakened by adding disturbance frequency. These predictions were consistent with test data in pre-peak stage of “rebound” type curve. For strain-softening type curves, this model did not only fit preferably with test data in the pre-peak stage but also had high fitting accuracy in the post-peak stage. This model can well characterize the mechanical properties and stress-strain behaviors of rock under the combination of static loading and frequent disturbance. These results can provide certain references for the evaluation of the safety and stability of deep rock engineering under high ground stress and frequent dynamic disturbance.