Application of full-section one-formation roadway excavation technology for open-off cut in Yindonggou Coal Mine

In view of the problems commonly existing in the traditional “initial excavation + secondary enlargement” process for large cross-section open-off cuts, such as long construction duration, difficult roof control, and high construction costs, we take the 110203 working face of Yindonggou Coal Mine as the engineering background and present a study and engineering practice of full-section one-formation excavation technology in soft rock strata. First, based on soft rock support theory and Protodyakonov’s arch failure theory, the key design parameters of anchor cable support are systematically calculated. Then, numerical simulations are conducted using COMSOL software to investigate the stress field and deformation characteristics of the surrounding rock under optimized support conditions. The simulation results show that the optimized support system can effectively control the maximum roof settlement within 130 mm. In addition, an innovative regional step-by-step full-section one-formation excavation process of “slot cutting first and then block mining” is proposed, which realizes man-machine separation and synchronous and efficient operation of excavation, support, and transportation. Field construction shows that this technology increases the average daily excavation rate to 8.0 m, shortens the construction period by about 20 days, and saves support costs by about 45,000 yuan. The research results fully verify the effectiveness of this technology in soft rock and can provide a theoretical basis and practical reference for the rapid construction of large cross-section roadways under similar weak surrounding rock conditions.