In order to solve the drilling bit jammed,drilling bit buried,low drilling cuttings discharging,serious gas outburst,low mechanization level and others occurred when the conventional drilling rods applied to the borehole drilling in the medium soft seam or coal and gas outburst seam,a new triangular drilling rod was researched and developed.

Analysis on coal quality at light mining face in “three-soft”middle thick seam;

Numerical simulation for bolting net spray composite support of three soft coal seam tunnel

Analysed the reason of roadway supporting problem,based on heave problem of roadway in three soft coal seam,depth of pressure-relief bore hole was optimizated with numerical simulation,specific solution was proposed,too.

Application of water injection to soften coal seam at mechanized caving mining face of the first mine of Meihe;

Study on fastly extincting burst technique when tunneling in soft coal seam

Improving the penetrability of soft coal seam with self-excited oscillation water jet

Based on analysis about status of coal seam infusion technology and soft coal seam preventing rib spalling technology and used coal’s failure mechanism、strength theory and coal’s wetting mechanism, the mechanism of shallow holes infusion at coal wall preventing rib spalling in soft coal seam was analyzed.