Experimental Investigation of the Dynamic Impact Failure of Bolted Rock With Different Anchoring Angles

Abstract

Bolt support mechanisms represent a key technique to support the surrounding rock in coal mines. In deep rock engineering applications, the bolt-supported structure of the surrounding rock of a deep roadway under high bearing stress may fail under dynamic loads such as those of blasting vibrations and earthquake motion. In this study, dynamic uniaxial compression tests were conducted on steel bar reinforced rock to investigate the rockbolt performance under dynamic loading. The deformation of the specimen surface and rockbolt was recorded during the test. The strengths and failure modes of the bolted rock samples were investigated. The results show that the bolt and rock deform asynchronously when the bolted specimen is subjected to a dynamic load, and the time of the asynchronous deformation of the specimens with different bolt angles is considerably different. When the stress wave acts along the direction of the bolt, it is more likely to cause the failure of the bolted specimen. Anchorage agents should be employed to realize the synchronous deformation of the bolt and rock mass. The slip and dislocation of the anchorage agent/rock surface and anchorage agent/bolt interface are the key factors influencing the failure of bolted specimens. The influence of a dynamic stress wave on the surrounding rock support structure of a deep roadway can be effectively reduced by improving the antisliding characteristics of the anchoring agent and increasing the bolt density. The research results can provide theoretical guidance and serve as a reference to realize the reinforcement engineering of underground permanent chambers and roadways.