Study of energy absorption principle of anti-bump bolt-cable

WANG Aiwen; PAN Yishan; ZHAO Baoyou; LI Zhonghua; LI Guozhen; DAI Lianpeng

Abstract：To satisfy the special requirements of bolt used in bump-prone roadways,an energyabsorption anchor-cable was invented based on the extrusion-friction energy absorption characteristics of hex pipe.The invented anchor-cable consists of an energy absorption sleeve with a embedded hex pipe,a bolt with a friction roller on its head pass through the hex pipe,a bundle of strands and an energy absorption device attached to the other head of the bolt.The relation between wall thickness of hex pipe,roller radius and sleeve inner radius were derived by analyzing the geometrical parameters and deformation characteristics of the invented anchor-cable.Mechanics analysis of the hex pipe in the process of extrusion deformation was conducted on the base of plastic bending theory,numerical simulation and laboratory results.The results show that,for a given wall thickness and sleeve inner radius,once the friction roller radius is less than its critical radius,the friction roller plays a role of extrusion-friction to the hex pipe,and the resistance increases to a constant value gradually as the friction roller extruds into the hex pipe entirely.When friction roller radius is larger than its critical radius,along with the roller extruding,the sleeve begin to provide radial compressive loads to hex pipe,which induces the friction resistance increased significantly.There is a linear relationship between the roller length and energy-absorption resistance.The structure parameters of the invented anchor-cable of average resistance 140 kN were presented.And a case study was also provided to illustrate its principle of anti-bump.