Stability lost causes and control technology of mining gateway in deep mine with contiguous seams

In order to solve high difficult control of the surrounding rock along the mining gateway under the dynamic mining condition of the contiguous seams in deep mine,the theoretical analysis and site exploration combined method was applied to analyze the deformation and stability lost causes of the mining gateway under the minin g condition of the contiguous seams in the deep mine. The analysis showed that the mine complicated high stress environment,the surrounding rock weakening,support me thod and irrational parameters of the gateway would be the key factors to cause the deformation and stability lost of the mining gateway. Based on the circumstances,with t he comprehensive application of the surrounding rock control principle with the“surrounding rock stress releasing,surrounding rock enhanced support,surrounding rock mod ified enhanced strength and surrounding rock stress migration" ,a surrounding rock control countermeasures combined with the' "bolt 1 steel mesh 1 shotcreting yield support + pre- stress anchor enhanced support + bolt 1 grouting modified + large diameter borehole pressure releasing' were provided according to the actual conditions. The site a pplication results showed that the surface deformation value of the gateway was not over 200 mm,cracks occurred in the gateway locally,individual bolt and anchor were fai lure and there was no floor heave and wall spalling occurred. During the gateway driving period,the max convergence between the two sidewalls was75 mm and the max C onvergence between the roof and floor was 56 mm. During the mining operation period of the coal mining face,the max convergence between the two sidewalls was 101 m m and the max convergence between the roof and floor was 77 mm.