Bending energy storage mechanical model of layered composite roof structure in coal mining.

The Layered Composite Roof Structure (LCRS) is a common bearing structure consisting of multiple layers of rock above a coal seam, and the energy stored in this structure plays an important role in the occurrence of rockburst. Few studies have been conducted on the theoretical modeling of energy storage in LCRS. This study theoretically developed a bending energy storage model for LCRS under three conditions, and the theoretical model was verified by simulation and experimental data.

Mechanical behavior and reloading reinforcement characteristics of fractured coal under low confining pressure.

To study the basic mechanical behavior and the reloading reinforcement characteristics of fractured coal, conventional triaxial loading tests with different fissure angle were first carried out. On this basis, conventional triaxial loading and unloading tests were conducted to investigate the reloading reinforcement characteristics of fractured coal. The results reveal that when the fissure angle was small, the stress-strain curve exhibited the multi-peak phenomena.