Mechanism of Time-Dependent Instability of Deep Soft-Rock Roadway and Crack-Filling Reinforcement Technology

Soft broken surrounding rock exhibits obvious rheological properties and time-dependent weakening effects under the action of deep high-ground stress, leading to increasingly prominent problem sustained large deformation in roadways. In this study, with II5 Rail Rise Zhuxianzhuang Coal Mine as an example, mechanism control technology damage instability a soft-rock roadway were explored through field observation numerical simulation. The research results show that range loose circle fractured can reach 3.0 m. expansion shallow cracks causes primary plastic secondary rock, rate increasing by 21.4% every 55 days on average, which ultimately induces failure rock. Based instability, high-preload bolt + deep- shallow-borehole crack filling was proposed. reduces ensures stability inhibiting propagation reinforcing