Abstract

Due to the high geo-stress state of the surrounding rock mass in deep rock engineering, which attends to induce large deformation, rock burst, zonal disintegration and other disasters, the traditional theories of statics continuum rock mechanics cannot explain many problems in the deep rock engineering sufficiently. This article presents a new dynamic constitutive model in the view of dynamic failure, considering the release, dissipation and transfer of energy under the unloading of deep rock mass, during which process the volume deformation experience elastic resilience and volumetric dilatation, and the shearing deformation may experience pre-peak (elastic and internal frictional hardening stages) and post-peak (softening and residual failure stages) stages. This model also describes the relationship of the elastic resilience and volumetric dilatation with time, which establish the volume deformation constitutive model. And fracture lag time and failure time are employed to establish the rheological equation and strength evolution equation. With this model three numerical simulations had been carried out in different deep rock engineering to represent phenomenon and analysis mechanism of large deformation, rock burst and zonal disintegration

1. INTRODUCTION

With the stable development of the economy and national defense, underground engineering tends to be constructed at the deep rock mass, such as thousands meter depth mining tunnels(Niechuan coal mine in China and gold mine in South Africa), seepage tunnels at hydropower station, nuclear wastes storages and deep national defense facilities(North American Aerospace Defense Command). New characteristic and scientific phenomena have been found in the deep rock engineering, which have many differences to the shadow underground engineering. The main differences of the deep rock environment to shallow depth are high geostress, high temperature, high osmotic pressure and large turbulence caused by excavation [1]. Therefore, the traditional theories of statics continuum rock mechanics cannot explain those problems in the deep rock engineering sufficiently [2,3].

This content is only available via PDF.
You can access this article if you purchase or spend a download.