In-Situ Stress Characteristics and Optimal Support Design of Deep Roadway

In view of the complex geological environment of deep roadways, the intense deformation of surrounding rocks, and the deformation of roadways reaching hundreds of millimeters, a dynamic optimal support design scheme was proposed. It is based on in-situ stress measurement, full-range monitoring of force-measuring bolts, and high pre-tightening force full-length anchoring technology, and modified by numerical simulation. Taking the transportation roadway of 1621(1) working face of Pansan Coal Mine in Huainan as an example, the stress relief method was used to measure the in-situ stress, and the force measuring bolt was installed at the key position of the tunnel to monitor and record the axial force of the bolt in real time. Combined with the numerical simulation, the support schemes before and after optimization were compared. The results show that horizontal stress is the main factor in deep roadway. With the increase of the angle between the direction of roadway driving and the direction of maximum horizontal principal stress and the increase of the principal stress difference, the deformation of roadway increases rapidly. Due to its small pre-tightening force in existing support schemes, the full-length anchorage cannot play its full role, and the shallow roof of roadway shows intense deformation. In the optimized support design scheme, the anti-deformation ability of surrounding rock is improved by high pre-tightening force combined with full-length anchorage support. And the characteristics improvement and the effective stress increase of surrounding rock can reduce the deformation of roadway, thus contributing to a sound support effect. © 2020, Editorial Department, Journal of South China University of Technology. All right reserved.