In order to solve the surrounding rock control problems in deep gob-side entry retaining

the working face 1126 with large mining height of Xingdong mine (850 m occurrence depth) was taken as research subject. Then

by means of UDEC simulation

we analyze surrounding rock response character with different subsidence amounts of key block B. Analysis result shows that: ①the deviatoric stress peak value of coal sides and its position have linear relationship with subsidence amount of key block B

and they transfer to deep part; ②deformation in deep part of coal sides has weak response to subsidence amount of key block B

and the closer to coal side surface

the more sensibility the coal sides has

therefore

there is an obvious inflection between the deep and shallow surrounding rock displacement; ③the roof subsidence amount and sides deformation amount have positive exponential relationship with the subsidence of key block B; ④along with key block B settling

broken form of coal sides experiences the following progress: unstable triangular block slide →X conjugate broken →double X conjugate broken. Therefore

some conclusions are made as follows: ①the roadside gob backfilling in can effectively limit the driving effect from key block C to block B; ②steel-concrete support can adapt subsidence feature of key block B well and has strong compression resistance and bending character; ③the high performance and high pre-stressed anchor can better improve the load capacity and deformation resistance ability of anchoring body; ④the roof truss anchor cable can be anchored in key block B that has solid and reliable anchoring basis

and

side cable can be anchored the area within the displacement inflection by passing through potential slip surface in order to restrict the side structural slip. Based on the above analysis

a collaborative control program was put forward which consists of roadside gob backfilling

steel-concrete support

roof truss anchor cable

side cable and high strength and high pre-stressed anchor. Thirty days after the entry retained

surrounding rock deformation tends to be stable. In addition

the relative displacement amount of roof and floor is 613 mm

and the other one of two sides is 374 mm

which achieves the effective control of gob-side retaining entry surrounding rock in deep mining with large mining height.