Research on Deformation and Failure Mechanism of Surrounding Rock in Inclined Strata with Soft-Hard Interbedded Roadways

In order to address the challenge of stability control of surrounding rock in roadways under complex geological conditions such as deep high-stress inclined strata and soft-hard interbedding, a comprehensive approach combining similarity model tests and complex variable function analysis with the Adam optimization algorithm was employed. This approach was utilized to obtain the stress and failure characteristics of surrounding rock in roadways under inclined strata and soft-hard interbedding conditions, elucidating the stability failure mechanism of surrounding rock in roadways. The research results indicate that: the internal stress direction in inclined strata shows obvious orientation, tending to be perpendicular to the stratigraphic boundary; the stress distribution in roadway surrounding rock varies with the inclination direction of the strata. Specifically, when the strata inclination angle is clockwise, stress concentration tends to occur on the left sidewall and right floor of the roadway; conversely, when the strata inclination angle is counterclockwise, stress concentration tends to occur on the right sidewall and left floor of the roadway. The use of the Adam optimization algorithm for solving mapping functions demonstrates superiority, with a solution time of only 1.25 s and high accuracy. When the number of coefficient terms in the mapping function is 9, the average error is only 0.17%, which is 0.34 times lower compared to other optimization methods, with the required number of iterations reduced by 0.64, significantly reducing subsequent computational pressure. For cross-layer roadways with soft-hard interbedding surrounding rock, the deformation and failure of roadways are closely related to the interface position between the rock layers, with deformation more likely to occur in the soft rock area and with larger deformations. Under conditions of high stress, when facing both the soft-hard interbedding and inclined strata issues simultaneously, priority should be given to addressing the soft-hard interbedding problem in supporting measures. We employed a similar model experiment to simulate the progressive failure process of surrounding rock in roadways with soft-hard interlayers in inclined strata under support conditions. We utilized digital image correlation method to analyze displacements.Additionally, complex variable functions were employed to analyze the deformation of surrounding rock in roadways under inclined strata and compared with model test results.We integrated Adam optimization technique to achieve high-precision solutions for the coefficients of the roadway mapping function.Upon solving for the coefficients of the circular exterior analytic function when the series of the mapping function is 9, a solution matrix was obtained, addressing the challenging problem of solving asymmetric roadway configurations.