Finite Element Simulation on the Interface Bonding Performance of Microrockbolt-Grouting Body.

China's grotto temples have suffered from the erosion caused by shallow-surface peeling diseases for many years, and the common protection technology cannot solve such problems. Therefore, in view of the characteristics of wide distribution, small rock separation parts, and shallow layers of spalling diseases in cave temples, the microrockbolt anchoring technology was adopted for treatment. On the basis of the finite element method, the pulling process of microrockbolt-grouting body was simulated, the interface bonding mechanical property between microrockbolt and grouting materials was explored, and the influence of different rockbolt diameters and anchorage lengths on the microrockbolt pulling force was analyzed under monotonic load. Results show that all the failure forms are bolt pulling out failure. With the increase in anchorage length and reinforcement diameter, the axial stress in the anchoring section decreases gradually, and the stress decreases almost uniformly along the anchorage length. The increase in steel bar diameter causes the ultimate pulling force of microbolt to increase. With the increasing of anchorage length, the ultimate pulling force of microbolt increases, but the increase rate decreases. The average interface bond strength decreases when the anchorage length is 100-250 mm. The conclusions obtained in this study provide a significantly reference for the microrockbolt anchoring treatment in cave temples with shallow-surface spalling diseases. [ABSTRACT FROM AUTHOR]