Weakening of Roof in Thick Flat-Lying Coal Seams by Implementing Seam Floor Layered Mining Methods

Abstract

Heavy rock falls of coal roof cause increased pressure load on powered roof support systems during the mining of first layers in seams III and IV-V of Tomusinsky coal field. Moreover, the complex morphology of the seam creates additional difficulties in downward working of seam layers. All these factors call for validation of thick flat-lying coal seams mining methods that involve longwall face layered floor mining as an alternative to any kind of artificially induced weakening of coal roof.

Nonimpact rock pressure regulation with energy recovery into the hydraulic system of the longwall powered support

“…An increased MGC range [16][17][18] results in a greater gap between the technically possible and actual production rates of MLFC and affects work safety [19][20][21] and economic efficiency of underground coal mining [22]. New requirements for MLFC have naturally occurred, in particular, it has become essential to provide them with adaptability to changing mining-geological conditions [23,24].…”