Application and research of flexible mesh in tunnel protection system

Rockbursts in tunnels frequently lead to casualties, equipment damage, project delays, and other severe consequences. This paper establishes a flexible protection system and solves the problems of insufficient strength and concrete rebound during the application of new materials. Initially, a comparison test between flexible and metal mesh protection systems was carried out along the CZ Railway tunnel, and the flexible protection system showed significant advantages in terms of efficiency, safety and economy. Subsequently, the flexible mesh was optimally designed, static and dynamic tests on the improved flexible mesh. The single rib tensile strength and node stripping force of the improved flexible mesh were improved, and effectively intercepting rock impact energy with 19.8 kJ/m2. Finally, physical testing of the flexible protection system was conducted using the developed scale model test apparatus. These trials established that combining 0.7 m rockbolt spacing with waterborne coating application achieves the reduction in shotcrete rebound. The results provide critical references for implementing flexible protection systems in rockburst mitigation.