Failure characteristics & control measures of bolt-arch combined supportin roadways buried in inclined strata

In order to clarify the failure mechanism of bolt-arch support in inclined formation roadways and seek the countermeasures for surrounding rock deformation, taking the typical case as the engineering background, the bolt-arch numerical simulation platform in FLAC3D was used to carry out the numerical simulation test under different dip angles.The results show that:①The stratum inclination had a significant impact on roadway deformation, the failure of surrounding rock, rock bolts and supporting arch were obvious asymmetry, and roadway sidewall on the down-tilt direction tended to be more severely deformed.②The deformation of roadway roof and ribs were less affected by the increasing dip of strata, but the floor heave volume increases significantly with the increase of the inclination angle.Aiming at the asymmetric deformation and failure characteristics of roadway, taking the model of 20° dip strata as an example, the numerical simulation comparative analysis of three optimization schemes were further carried out.The results show that the control effect obtained by increasing the diameter of the bolt was insignificant, and the arch was still subject to buckling deformation and thus caused overall failure, but the application of the locking arch bolt in the key part improved the structural integrity of the arch structure.Based on this, the asymmetrical support measures such as single-sided locking archway of inclined strata roadway were proposed and verified on site.