Electrohydraulic control systems for powered roof supports in hazardous conditions of mining tremors

This paper presents an application of a powered roof support equipped with an electrohydraulic control system to underground excavations with mining tremors hazard. The research included an analysis of mining and geological conditions of longwall 2, seam 506, section K in Wujek Mine, Ruch Śląsk and an assessment of a system providing protection from dynamic loads for a hydraulic leg of Glinik-12/23-POz powered roof support. The final results of the research include an optimization of a powered support's protection system designed to work in mining and geological conditions of longwall 2 located in seam 506 K. The optimization was based on tests of the hydraulic leg and the support system for hazardous conditions of mining tremors. The process included proper operation of relief valves, leg's valves (check control valve), bearing capacity of the leg and a cross-bar.