Abstract
In cable bolt reaming and anchoring of a soft-rock roadway tunnel, the cable bolt and its stirring end are in direct contact with the wall of the drilling hole, which can easily damage the structure of the drilling hole. The cable bolt cannot effectively break and stir the resin cartridge in the reaming area. The anchoring force of the cable bolt is low and the deformation of the surrounding rock is large. The characteristics of cable bolt reaming and anchoring in a soft-rock roadway are analyzed systematically. The influence of the cable bolt on the reaming and anchoring performance is calculated and analyzed in terms of cable bolt stirring, anchoring solid strength, pull-out force, cable bolt concentricity, and the influence of the drilling hole wall. A multi-stage reaming and anchoring reinforcement (MRAR) is developed, and the mechanism through which the MRAR strengthens the reaming and anchoring of a cable bolt is analyzed theoretically. Through numerical simulation and laboratory and field experiments, the working performance of the MRAR is verified comprehensively. The results show that the MRAR greatly improves the dynamic stirring action of the cable bolt, compactness and strength of the anchoring solid, drilling performance, concentricity, pull-out force, and pretension. It can ensure to the maximum extent that all the resin cartridge in the reaming area is stirred, reacted, and firmly bonded with the hole wall. It greatly improves the reaming and anchoring and roof deformation control of the cable bolt in the soft-rock roadway. This technology has practical significance for improving the reaming and anchoring of a cable bolt and the bearing capacity of the surrounding rock in a soft-rock roadway tunnel.