Design and operation of powered supports for longwall mining : Barczak, T M J Min Metal FuelsV40, N1, Jan 1992, P10–17

Abstract

Throughout the history of longwall mining, the design of the roof support system has been critical to the success of the mining operation. Early forms of longwall mining used wood props for face support and packwalls made from roof and floor rock to control caving of the immediate roof. These systems were replaced by powered roof supports that could be advanced easily while allowing the strata to cave behind them. The first powered roof supports were simple frame and chock structures. These designs were poor in their ability to resist horizontal displacements and moment loading caused by the strata dynamics during the caving process. They often experienced difficulty and failure. The shield greatly improved kinematic stability by providing a horizontal stiffness by mechanically connecting the canopy to the base in a truss-like fashion. The success of the shield support promoted the application of the longwall mining method in highly faulted and massive strata conditions where caving was difficult to control and where chock and frame supports were inadequate. The purpose of this paper is to provide some insights into optimizing shield design and utilization. Motivations for optimization are to minimize support costs and maximize shield life while providing effective groundmore » control in all mining conditions.« less