Determining the pressure increase in the hydraulic cylinders of powered roof support based on actual measurements

Powered roof support in a longwall operation is designed to maintain a safe working area and allow the immediate roof to fail and collapse behind the support. The powered supports are loaded using large hydraulic pumps with non-return and preset-yielding valves. In addition to providing support to the immediate roof in the longwall production area, it also moves the armoured face conveyor and shearer forward as coal mining progresses. The research aimed to analyse the changes in the pressure values in the powered roof support section's hydraulic cylinders in relation to the occurrence of rock mass movements in the roof. The pressure measurements are based on the sensors in the sub-piston space of the powered roof support hydraulic prop located in the steel wall. The results allow a correlation to be developed between the roof movement and the loads generated in the hydraulic cylinders.