Study on Combined Joist Support Technology of High Geostress Gateway .

Based on high support difficult problems of mining gateway in high stress and large cross section coal mining face of Xinjing Mine, the combined joist su pport technology was applied to the gateway of No.7204 coal mining face in No.2 block of Lu'nan No.3 seam.Based on an analysis on the structure features of the co mbined joist, parameters of a steel band were designed, the performances and support capacity of the flower bowl steel band in the support pressure loading were simu lated and analyzed and an analysis was conducted on the support effect. The results showed that the support pressure loading performances of the bowls and dishes ty pe steel band were excellent and with the articulated connection method of the bolt and anchor, the steel band could form a combined plate and bracket structure. The bowls and dishes type steel band would be simple and convenient in site construction, the deformation value of the supported surrounding rock was obviously less than the conventional steel band support and the cross section convergence of the gateway could be controlled in less than 12%. There was no obvious difference in the loa d variation of the bolt and anchor and the high support difficult problems of the mining gateway in the high stress and large cross section coal mining face were effective ly solved.