Deformation Characteristics and Countermeasures of Roadway Surrounding Rock in Gas- and Water-Rich Coal Seam

The stability of roadway surrounding rock gas and water rich coal seam is a fundamental concern for achieving safe and efficient mining operations. In this study, a fluid-solid coupling mathematical model considering plastic failure was derived, and a solution method of bolt-cable combined support under multi-field coupling conditions was proposed. The model was introduced into COMSOL Multiphysics software to explore the deformation characteristics of surrounding rock in gas and water-rich coal seam. Results show that increased water content reduces the strength and elastic modulus of coal and rock mass, altering failure modes. Compared to gas, water has a more significant impact on surrounding rock deformation, increasing roof-to-floor and side-to-side deformation by up to 15.6% and 21.8%, respectively. To address these challenges, the combined support of bolt-cable and excavation was proposed. Both numerical simulations and field test results conclusively indicate that, under identical support parameters, roadway excavation along the roof provides significantly enhanced control over the stability of surrounding rock. The findings provide critical insights and methodological advancements for the control and design of roadway support in gas and water rich coal seam.