Title of Paper:Numerical simulation of rockburst failure induced transient unloading under different axial stress

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Date of Publication:2011-06-01

Journal:Dongbei Daxue Xuebao/Journal of Northeastern University

Included Journals:EI、PKU、ISTIC、Scopus

Volume:32

Issue:6

Page Number:859-863

ISSN No.:10053026

Abstract:The numerical tests of rock specimens were simulated by using the code of RFPA 2D with confining pressure transiently unloaded. The objective is to study the mechanism and process of the rockburst under different geostatic stress conditions, which is caused by transient unloading during the excavation of the actual engineering such as underground tunnels and chambers. A numerical test of uniaxial loading was carried out, and then several rockburst experiments with same confining pressure transiently unloaded were carried out under different axial stresses. The simulation results verified that (1) the failure of specimens is concentrated on some narrow belt. Only a few micro-seismic events happen before total failure, whereas large area damage and cracks occur after transiently unloading. Then critical breach on the whole specimen is caused nearby the free surface during unloading test. On the contrary, micro-seismic events hardly happen before transient unloading; (2) the combination of primary slabby shade failure of split and secondary shearing failure is presented when confining pressure is quickly unloaded under a low axial stress. Block breakage of shearing failure takes on principally when confining pressure is moved away suddenly under high axial stress.