Simulation and Experiment of Self-adaptive Device for Hydraulic Support with Roadway Anchor Bolt

For the two support methods currently used in coal mine roadways, namely bolt support and hydraulic support, the supporting capacity of a single support method is limited under various complex conditions. The impact resistance of combined support is 30% − 50% higher than that of single support, which can improve the stability of coal mine roadways. However, the problems of stress concentration and impact damage caused by the protrusion of bolt ends in the collaborative operation of the hydraulic support-bolt support system have not been well solved so far.In this paper, an innovative hydraulic support top beam buffer ball device is designed, which well addresses this issue. Through laboratory tension-compression tests, the schemes of dense/loose nylon ball arrangements and the addition of rubber soft balls are compared. The data show that the loose nylon ball arrangement increases the total energy absorption by 77.8% more than the dense nylon ball arrangement. Furthermore, a finite element model is established using ABAQUS to simulate the mechanical response under impact load, verifying the effectiveness of the device.