Failure Characteristics and Stability Control of Roadway Surrounding Rocks under Different Lateral Pressure Coefficients

The stability control of mining roadways is crucial in ensuring the safe and efficient mining of deep coal resources. Given the effect of mining stress on the working face, the support scheme of such roadways, which is designed based on the original in-situ stress parameters, often presents support-related problems. A mining roadway on the 1131 working face of Zhujidong Coal Mine in the Huainan mining area, China was taken as the engineering background of this study. To explore the influence of mining stress on the stability control of this roadway, the 2-dimensional (2D) Particle Flow Code (PFC) numerical simulation software was used to perform a simulation study on the stress distribution characteristics and deformation failure laws of the surrounding rocks under the change in the roadway lateral pressure coefficient caused by the mining stress. An improved support scheme that considers the influence of varying lateral pressure coefficient on the mining roadway was then proposed. Results show that when the lateral pressure coefficient increased from 1 to 1.4, the maximum principal stress (61.2 MPa) is observed at 2.9 m inside the roof of the surrounding rocks in the roadway. When the lateral pressure coefficient decreases from 1 to 0.4, the maximum principal stress (46.2 MPa) is observed at 2.2 m inside the surrounding rock of sidewalls of the roadway, and failure occurs. These findings suggest that the deformation and failure of surrounding rocks are affected regardless of the lateral pressure coefficient increase or decrease. On this basis, the lengths of the anchor bolts in the roof and sidewalls in the original support method are increased from 2,200 mm to 3,000 mm and 2,500 mm, respectively. The field monitoring results indicate that the improved support method mitigates the deformation and realizes the stability control of the roadway surrounding rocks. The findings of this study could provide a scientific basis for the parameter design of roadway support. © 2020 All Rights Reserved