Abstract:
The practice of impact resistance support in dangerous roadways has shown that energy absorbing and buffering components can improve the impact resistance performance of rockbolt support systems. A rubber cushion layer was used as an energy absorbing and buffering component, and an impact test platform was used to conduct impact loading on rockbolt support systems with and without energy absorbing cushion layers. The response characteristics of parameters such as rockbolt deformation, load, energy absorption, and surrounding rock fragmentation are compared to reveal the impact mechanism of energy absorbing buffer components on the impact resistance performance of rockbolt support systems. Experimental studies have shown that: (1) when the rockbolt support system experiences impact, the dynamic response of the rockbolt load is earlier than the deformation, and the rockbolt load, deformation, and response "time velocity" are significantly reduced when installing buffer components, indicating that buffer components can improve the impact resistance performance of the rockbolt support system; (2) The buffer components consume some impact energy through plastic deformation, thereby reducing the energy absorption demand of the main components in the support system; (3) Buffer components are conducive to achieving balanced stress distribution of rockbolt, cooperating with various support components to enhance the impact resistance performance of the support system, and significantly reducing the standard deviation of impact response indicators; (4) When installing buffer components, the degree of rock damage is significantly reduced, and indicators such as the length of rock crack traces, fractal dimension, and quality loss ratio are significantly reduced. The research results can provide reference for the optimization design of support systems for impact dangerous tunnels.