Aiming at the characteristics of large falling height and complex falling configuration in full-mechanized caving mining,three-dimensional distinct element code-3DEC is employed to simulate falling rules of surrounding rock in gob,movement direction of rock beam and possible dynamic loading brought by it with different collapse geometry parameters in full-mechanized caving mining face.

According to Datong "dual hard" full-mechanized caving mining conditions,the practice of fire prevention and extinguishment technology by optimizing the ventilation systems,balancing gas pressure,spraying frog in working face,injecting nitrogen into coal seam,and grouting into gob in full-mechanized caving mining face was discussed.

Based on in-situ observation of underground pressure in full-mechanized caving mining coal seam with large dip angle and 1000m deep in Zhaogezhuang Colliery,Kailuan Group,the behavior of underground pressure of mining face with large dip angle is fully analyzed in this paper.

in the process of determining the length of mining face which influences the effect of mining,many factors influence the determination of the length for fully mechanized top-coal caving face.

In this paper,the mechanical field characteristics of fully mechanized top-coal caving(FMTC) laneway surrounding rock are researched systematacially based on the results of in-situ measurement combined with numerical simulation in different mining thickness.