Abstract
Due to rock damage in close-range tunnels and difficulty controlling stability, proposes a precise surrounding rock control concept of goaf-retaining roadways in close-range without coal pillars. A mechanical model for the load transfer of overlying rock strata in the goaf under the roof cutting structure of the roadway is constructed, and a precise quantitative support design method for the surrounding rock without coal pillars is formed, with the main steps being the mechanical rock properties research, the design of support strength, and the optimization of support structure schemes. To clarify the mechanical properties of high-strength support structures for steel-reinforced concrete pillars, indoor tests were conducted on long pillar supports with different aspect ratios to analyse the deformation failure modes and bearing performance of long pillars. Through numerical simulation, the peak support pressure of the roadway was reduced by 41.2% due to coordinated support and cutting, effectively reinforcing the roof and cutting off the stress transmission path. The deformation and failure control laws of the surrounding rock with different support schemes for goaf-retaining roadways in close-range were revealed. Successful application at Xinchazhuang coal mine significantly improved the stability control of the surrounding rock in the goaf compared to traditional support techniques.