Deformation and failure law and control technology of right-angle trapezoidal mining roadway in deep mine

The cross section formed by roadway in deep inclined coal seam tunnelling along the roof is right-angle trapezoid. In view of the asymmetric deformation and control of the surrounding rock in the mining process of this roadway type, taking the right-angle trapezoid roadway of 74104 working face as the engineering background, the deformation and failure law and control technology of the right-angle trapezoid roadway under the influence of deep mining were studied by field measurement, theoretical analysis and numerical simulation. The research has shown that the asymmetric deformation and failure were mainly manifested in asymmetric deformation of high and low sides, asymmetric deformation and failure of upper and lower parts of high and low sides, and asymmetric deformation of roof and floor along the middle line of roadway. The typical failure mode of rectangular trapezoidal roadway was the upper sliding of high side. The asymmetric stress caused by mining was the direct reason for the asymmetric deformation of roadway. The stress difference between high and low sides of right-angle trapezoidal roadway in area A (high side goaf+low side mining) could reach 18. 59 MPa, which was positively correlated with the asymmetric deformation of roadway. The maximum roof subsidence position of the rectangular trapezoidal roadway shifted to the high side, and the maximum floor heave position shifted to the low side. The deformation of the high side was significantly greater than that of the low side, and the deformation control focused on the coal pillar of the high side. The proposed control method of roadway surrounding rock “combined support+high reinforcement+low relief” meets requirements of safe production, and the field application effect is better. © 2023 China University of Mining and Technology. All rights reserved.