Energy Dissipation of Hydraulic Support Columns under Rockfall Impact Load in Steeply Dipping Coal Seams

Abstract

Rockfall disasters have long restricted the further improvement of the safety level of steeply dipping coal seams (SDCSs). When a rockfall disaster occurs, it causes damage to the hydraulic support and other equipment at the working face. An effective way to carry out protection design is using the law of rockfall migration and energy evolution. Therefore, this study used the polyhedral rockfall migration and its impact process on the hydraulic support equipment of the working face as the research object and analyzed the influence of relevant parameters on the maximum contact deformation, maximum impact force, and energy absorption of the column during the collision and contact between the rockfall and the hydraulic support column. Firstly, with hexahedral rockfall as an example, the migration process of rockfall was simulated using PFC3D software. Secondly, according to the Hertz contact theory, the contact model of the shock process between the rockfall and the hydraulic support column was constructed, and the maximum deformation and maximum impact force of the collision contact between the rockfall and the column were obtained. Finally, the Hamilton principle and the Galerkin discrete method were used to construct the dynamic model of the collision between the rockfall and the column, and the energy evolution law of the shock process between the rockfall and the column was studied. The conclusions of this paper can provide a certain theoretical basis for the prediction of rockfall disasters and the design of rockfall protection devices.