Research On Surrounding Rock Control Technology Of Coal Cavern Group Affected By Mining In Chaijiagou Mine

In this paper,the chamber group in the third panel of Chaijiagou mine is taken as the research object.Through in-depth field investigation,combined with engineering geological data and laboratory experiment analysis,the characteristics of chamber group instability and failure are obtained.Theoretical analysis and numerical simulation work are carried out around the surrounding rock activity law under the influence of mining,and then the influence law of different working faces on the surrounding rock of chamber group is obtained.Based on the principle of high-strength and stable support,this paper puts forward the control technology of surrounding rock of cavern group,and finally verifies the research results through the field industrial experiment.The main conclusions of this paper are that:(1)Caijiagou mine cavern group is a typical soft rock roadway under the influence of mining,which is mainly characterized by large displacement of the left and right sides,serious floor heave and other deformation features;support damage is mainly characterized by bolt cable failure,serious damage of surface protection components and so on.The analysis shows that the surrounding rock of the cavern group is seriously damaged due to the surrounding working face mining,the too small space between the caverns,the unreasonable selection of the support mode and parameters of the cavern group.(2)The results show that on the one hand,the whole supporting bearing structure is weakened due to the lack of support on the floor of the cavern group,and the weak area of the floor is destroyed first,then the stability of the whole bearing structure is destroyed in stages;on the other hand,it is difficult for a single anchor net support to play its supporting effect in the broken surrounding rock It is difficult to maintain the normal use of the surrounding rock under the influence of mining.(3)Based on the surrounding rock control of the cavern group under the influence of mining,the high-strength and stable support technology is proposed: first,the integrity of the surrounding rock is improved by surface grouting + internal grouting,and the anchor foundation is provided for the anchor cable,then the high prestressed anchor mesh is used for support,and finally the high prestressed anchor cable is used for reinforcement to form a complete bearing structure between the shallow foundation support and the deep surrounding rock,which is fully developed The bearing capacity of the deep rock mass improves the structural stability of the bearing structure of the support and the surrounding rock itself,and determines the optimal prestress matching value of the anchor cable,makes full use of the performance of each supporting structure,greatly improves the bearing capacity of the bearing structure under the influence of mining.(4)The field industrial test shows that the high-strength and stable bolt grouting support scheme can effectively improve the bearing capacity of the cavern group and achieve the goal of no expansion and repair of the cavern group in the whole service period.The thesis has 49 figures,6 tables and 82 references.