Study on Catastrophe Information Characteristics of Strain-Structural Plane Slip Rockburst in Deep Tunnels

Abstract

Rigid structural planes encountered during construction have an obvious influence on rockburst intensity and occurrence mechanism. The high-intensity rockburst induced by the structural plane poses a great threat to the safety construction of the tunnel. A novel 3D discrete element numerical analysis method for rockburst is proposed with the help of the bonded block model and multi-parameter rockburst energy index. According to this method, the influence of multivariate information characteristics such as stress, energy, fracture, and rockburst proneness index on the surrounding rock during the strain-structural plane slip rockburst in deep tunnels is systematically investigated. The results are drawn as follows: The results show that from the analysis of multivariate information characteristics of strain-structural plane slip rockburst, the rock between the plane and tunnel is a typical rockburst risk area. The dip angle, length, and relative distance of the structural plane have a significant influence on the multivariate catastrophe information characteristics of the surrounding rock: As the dip angle increases, the fracture propagation range within the risk rock expands, but the rockburst intensity and the occurrence range gradually decrease; as the length increases, the fracture propagation range, rockburst intensity and occurrence range within the risk rock increase slightly; as the relative distance increases, the fracture propagation range and rockburst intensity gradually weaken, and the occurrence range of rockburst first increases and then decreases. Using the “11.28” strain-structural plane slip rockburst case as a basis, engineering validation research was conducted. The simulation results are found to be essentially consistent with the rockburst condition on the field, validating the rationality and applicability of the novel rockburst analysis method proposed in this paper.

Keywords

• deep tunnel
• strain-structural plane slip rockburst
• bonded block model
• multivariate catastrophe information
• numerical simulation