Parameter optimization analysis and mechanical property test research based on reaming anchorage

Abstract

Aiming at the technical problems of poor anchoring performance and low anchoring force of soft coal and rock mass, the method of inverted wedge reaming at the bottom of anchor hole is proposed to improve the anchoring force. The mechanical characteristics of surrounding rock, anchor agent and anchor rod are analyzed by numerical simulation method, and the reaming parameters are optimized. Combined with the anchoring effect test of resin anchor agent in the laboratory, the length of reaming section is determined to be 120 mm, and the maximum reaming diameter is 58 mm as the best reaming parameter, developed reaming device; the pull-out comparative test of the anchor rod in the laboratory shows that the pull-out resistance provided by the reamed anchor is significantly higher than that of the normal anchor, and the average anchor force increases by 1.63 times. The anchor force decays less after the debonding between anchorage agent and borehole surrounding rock. The anchor body in the reaming section has a cyclic process of “compaction-failure-compaction” for the surrounding rock of the borehole, showing the characteristics of “ductile failure”, avoiding the large attenuation of the anchoring force, and playing an important guiding role in solving the technical problems of roadway support in soft coal and rock mass.

Keywords

• numerical simulation
• anchoring parameter
• soft coal and rock mass
• anchor pull out test
• slip failure