Instability mechanism and anchoring control technology of expansive weakly cemented soft rock roadway

A long-term discontinuous development of the plastic zone and broken zone of weakly ce- mented surrounding rock is the main reason for instability of the surrounding rock of a roadway. The load-bearing support concept of “allowable deformation + releasable pres- sure + limited deformation” for a weakly cemented soft rock roadway is proposed, and an “allow-release-limit” support structure mechanical model with U-shaped steel as the main body is established. Anchoring control measures of “U-shaped steel + flexible material wall backfill + key parts strengthening” can solve problems of large deformation and long defor- mation duration of weakly cemented roadways.