Theory study on the load on support of long wall with top coal caving with great mining height in extra thick coal seam

Numerical simulation and analytic method were applied to researching characteristics and mechanism of side falling in full-mechanized caving mining with large mining height and controllable factors of side and roof falling were quantized.

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.

Intenerating technique of top coal in fully mechanized top coal caving hard thick coal seam;

Support instability is a normal phenomenon in the fully mechanized top coal caving face with steep coal seams.

The effect of drawing top coal window parameter,drawing procedure,and drawing interval on coal-gangue flow field resulted from great mining height fully mechanized top coal caving was analyzed based on theory and loose material model experiment.

Research on fully mechanized top coal caving mining technology for ultra thick seam with high tenacity, easy to be combusted and hard to be falling;

Research on coal caving characteristics and caving technology for fully mechanized top coal caving mining face in thick seam with complicated parting structure;

Research on movement and displacement failure features of top coal and strata in fully mechanized top coal caving mining in thinner thick seam;