Abstract: The hydrogeological conditions of the Zhongjiu Iron Mine are complex,the top and bottom lithology of the deposit are mainly Gushan Formation and Zhouchongcun Formation,and the surrounding rock of the mine is mainly class IV bedrock with poor rock integrity. In the underground development project of the auxiliary shaft construction of the mine project,the -550 m horizontal water pump room has a large section span and the surrounding rock is broken,and the disturbance of the surrounding water silo blasting leads to the cracking,deformation,settlement of the top wall rock at the connection between the -550 m horizontal central substation and the water pump room,and even the risk of falling. In this regard,combining the technical advantages of curtain grouting and anchor cable support,the combined support and reinforcement technique of curtain grouting and long anchor cable is put forward,and the concrete construction technical scheme is designed. The basic idea of this technique is to make full use of the grouting curtain to cement the broken roof into a whole,and then use a long anchor cable to fix the joint roof to the stable rock,and finally complete the connection between the central substation and the water pump house by expanding the brush. According to the above technical ideas,the design of key technical parameters of curtain grouting and long anchor cable support at different positions is discussed in detail,and the effect of curtain grouting and long anchor cable support is analyzed in detail by numerical simulation coupling analysis method. The study results show that through curtain grouting construction,the reinforcement curtain can be formed on the roof of the joint and the two sides of the surrounding rock,and the properties of the surrounding rock at the joint can be greatly improved. The proposed combined support technology scheme and related technical parameter design have a certain reference value for the stability control of underground surrounding rock in similar mines.

Key words: curtain grouting,long anchor cable,support and reinforcement,broken surrounding rock