To solve the large deformation problem of deep gob-side entry retaining in soft rock under high stress

lithological characteristics of surrounding rock

failure modes of supporting structure and its evolutionary process are analyzed by the methods of field investigation

theoretical analysis and similar tests. Failure mechanisms of surrounding rock and its control technology are studied systematically. The results show that the large deformation inducements of surrounding rock are weak thick mudstone with softening property and water absorption behavior

as well as its fragmentation

dilatancy and long-term creep in strong disturbance and highly centralized stress state. The cross-section shape of roadway after deformation and failure of surrounding rock is obviously asymmetric in both horizontal and vertical directions. As the original supporting system of surrounding rock does not form into a complete bearing structure

each part of the supporting system is destroyed one by one. The failure sequences of surrounding rock are as following: (1) roof fracture of backfilling area

(2) backfill fracture under eccentric load

(3) rapid subsidence of roadway roof

(4) external crack drum and rib spalling of solid coal side

and as a result

the instability of the whole surrounding rock occurs. The partitioned coupling support and the quaternity control technology of surrounding rock are proposed

which take the roof of backfilling area as a key link. The technology can improve the overall stability of gob-side entry retaining

avoid support structure instability caused by local failure of surrounding rock

and ensure the safety and smoothness of roadway.