A Real Time Response Measure for Longwall Face Strata Conditions

In an earlier project a robust methodology and “offline” software was developed for interpreting the shield leg pressure sensor data coming from a longwall face in the context of support strata interaction using a novel characteristic load cycle analysis concept. It is possible to assess when a shield has too low a set pressure, too high  a set pressure and/or has an inadequate capacity for the conditions. In this project the software was extended to ‘on-line” allowing a real time response to changing strata conditions on a longwall. This necessitated extensive modifications to the off-line algorithms and the development of a Graphical User Interface (GUI). The new software was successfully installed at BMA’s Broadmeadow mine, which acted as the demonstration site for the project.

The new software enables modifications to be made to set pressures and mining strategies which will lead to a reduction or elimination of roof control problems. It is quite possible to successfully mine through periods of shield overloading if such events can be identified in a timely manner.  The software is also capable of identifying faulty shield leg components. Faults on shield legs can lead to roof control problems. The early identification and repair can reduce or eliminate this problem.  Existing software packages being used to access the pressure data were found either not to be capable of delineating load cycles or where they could the accuracy was low, making it impractical to use them in combination with the new advances in load cycle analysis.