Research on Support Method and Surrounding Rock Deformation Law of Secondary Gateway Retained Along Goaf

Based on the structural stability lost occurred from the serious failure of the gateway retained along the goaf of No.62110 air return gateway in Xinzhuan gzi Mine and the gateway reused later, a research was conducted on the support technology of the secondary gateway retained.The analysis showed that the failure ca uses of the gateway were the complicated geological conditions and the irrational previous support parameters.In combination with the pretension support theory of the seam gateway, the frame/bolt/grouting combined support plan with high strength, high stiffness and high pre-tension bolt, the anchor reinforcement and the shallow bor ehole grouting was determined.The rapid continued observation method was applied to the site measurement of the surrounding rock deformation in the gateway during the mining period of the coal mining face. The results showed that the high strength frame/bolt/grouting plan could rebuild the surrounding rock structure and could relax the activity serious degree of the roof.The 3055 m location behind the coal mining face would be the deformation serious scope of the gateway surrounding rock. Beyond the coal mining face 55 m, the deformation speed would be stable . After the repair plan conducted, the support effect was improved and the safety mining of the coal mi ning face could be ensured.