Design and application of high-prestress flexible impact-resistant truss cable support system for deep roadways

Abstract As coal mining operations extend to greater depths, the stress regime governing the surrounding rock of roadways becomes increasingly complex. Existing support schemes, often characterized by poor structural integrity and inadequate dynamic disturbance resistance, fail to effectively control rock deformation, thereby jeopardizing mine safety. This study focuses on the transport roadway of the 2803 working face at the Hetaoyu Coal Mine. To address the deficiencies of the current support strategy, a high-prestress, flexible, impact-resistant truss cable support system was developed, building upon a conventional truss bolt framework. Through an integrated approach combining numerical simulation and in-situ field measurement, a comparative analysis was conducted to evaluate the performance of the proposed support system against the original scheme during both roadway excavation and subsequent mining activities. The results demonstrate that the optimized system effectively redistributes stress within the surrounding rock under both static and dynamic disturbance conditions, fostering the formation of a composite load-bearing structure between the support elements and the surrounding rock. Field monitoring data reveal that, compared to roadways with the original support, the application of the optimized system reduces roof convergence by approximately 41% during excavation and 38% during mining period. Furthermore, rib-to-rib convergence is effectively contained, and the roof maintains its structural integrity without fracturing or collapsing. The implementation of the optimized truss system enhances the stability of deep roadways, providing a critical guarantee for safe and efficient underground coal extraction.