Damage evolution mechanism and deformation failure properties of a roadway in deep inclined rock strata

Abstract

Underground engineering excavation can lead to sharp stress change in the rock mass around the excavation surface, which can cause different degrees of rock damage, ultimately resulting in instability failure. Especially for inclined stratified rock mass that is ubiquitous on Earth, the evolution characteristics, development law and formation mechanism of an excavation damage zone are highly complicated due to its significant asymmetry. Therefore, the evolution mechanism and deformation failure properties of a typical deep roadway in inclined rock strata in Jinchuan Mine of China were investigated by means of a field investigation, theoretical analysis, similar model test and numerical simulation. The results indicate that the deformation failure of a roadway in deep inclined rock strata shows a prominent asymmetry and time sequence. Ground stress has a great influence on the development mode and evolution characteristics of the surrounding rock damage zone. However, as a deep ground stress environment tends to cause hydrostatic pressure, its leading role is gradually weakened. The structural planes control the damage evolution mode of the surrounding rock, an excavation damage zone developed parallel to the interface is formed around the goaf, and an overall instability of the roadway is caused by the sliding of surrounding rock along the structural plane. The conclusions of this study should provide a theoretical reference and demonstrate the key technologies that support underground engineering under similar geological conditions.