Experimental Study on Mechanical Properties and Failure Mechanisms of Rocks Anchored by CRLD Anchor Cables with Different Bedding Dip Angles
摘要
Understanding the mechanical properties of layered rock and its support system is a prerequisite and key to ensuring the stability of surrounding rock in roadways within layered rock masses. This study investigates the mechanical properties of unanchored rocks, single-anchored rocks, and double-anchored rocks with different bedding dip angles, based on a novel constant-resistance large-deformation (CRLD) anchor cable. Focusing on the differences in strength characteristics, deformation and failure evolution characteristics, and acoustic emission evolution characteristics among the various specimens, the following experimental patterns were identified: as the bedding dip angle increases, the elastic modulus, peak strength, and residual strength of all specimen types show a trend of first decreasing and then increasing. Moreover, as the number of CRLD anchor cable supports increases, the mechanical parameters of layered rock with different bedding dip angles exhibit significant improvement. By comparing the final failure characteristics of each specimen type, it was found that CRLD anchor cables can continuously and adequately mobilize the inherent strength of the bedrock in layered rock, effectively preventing the occurrence of single shear or tensile failure modes in layered rock with different bedding dip angles. Simultaneously, as the number of CRLD anchor cable supports increases, the distribution of acoustic emission counts in layered rock with different bedding dip angles becomes more uniform, the energy release process becomes smoother, and both the maximum count value and cumulative energy value decrease significantly. Finally, based on the concept of static toughness UP of anchored rock, the comprehensive mechanical property differences of CRLD anchored rocks with different bedding dip angles were calculated and analyzed. Furthermore, several engineering recommendations were proposed for the prevention and control of large deformation disasters in the surrounding rock of deep-layered rock mass roadways.