Deformation and failure law and control of surrounding rock in the large section chamber of Ulan Mulun Coal Mine

Abstract

In response to the deformation and failure of surrounding rock in large section chamber underground roadways of coal mines, this study focuses on the sorting and filling of large section chamber underground roadways in Ulan Mulun coal mine. Similar simulation experiments are conducted using monotonically increasing and constant load uniaxial compression methods to investigate the deformation and failure laws of surrounding rock in large section chamber underground roadways. The results show the following points. ① The failure evolution and deformation displacement trends of the two loading methods are similar in the compaction stage, elastic deformation stage, and micro fracture stable development stage. ② The sample using monotonically increasing loading method has fewer cracks but larger crack gaps. The sample suddenly breaks along the main crack, during which a large amount of debris flies out. The deformation of the sample is mainly concentrated at the boundary of the surrounding rock. More energy is released during the failure, but the duration of energy release after the peak is relatively short. ③ The stress of the specimen loaded with a constant load remains constant, and the strain slowly increases, during which a large number of small cracks are generated. The deformation position of the specimen mainly surrounds the chamber, and the energy released during failure is relatively small, but the duration of energy release after the peak is longer. Based on the deformation and failure law of the surrounding rock of the large section chamber, a bolt and cable support scheme is proposed. A long anchor cable is installed at the top of the chamber to connect the roof and the hard rock above it as a whole. The inclined anchor rods are installed at the coal rock interface of the roadway to tightly connect the coal rock interface with the surrounding rock mass. The numerical simulation results show that after support, the stress, displacement, and plastic zone of the surrounding rock are significantly reduced, the stability of the surrounding rock is greatly improved, and the support effect is good.

Keywords

• large cross-section chamber
• surrounding rock deformation and failure
• uniaxial compression experiment
• acoustic emission
• anchor cable support