Characteristic of Surface Cracks Caused by High-Intensity Mining - A Case Study

Crack is a main destroyed formation of high-intensity mining. Based on measured data, the difference between cracks caused by high-intensity mining and other mining methods had been studied. Control cracks showed obviously when using high intensity mining, and often gone with many small cracks. They always showed as couple, and the ground between them appeared as horst or rift valley, which destroyed the continuity of surface deformation. Cracks had been classed by reductive crack angle and dynamic (steady) crack angle by their develop process to meet the repair project. The characteristic of cracks in depth had been studied, and the calculate method of ultimate depth of them had been given, which will provide technical support for the need of engineering.