Understanding the Causes of Roof Control Problems on A Longwall Face from Shield Monitoring Data - a Case Study

The results of an assessment aimed at understanding the shield loading mechanisms associated with strata related issues on a longwall face are detailed. Shield load cycle analysis theories developed by the authors were used to quantify the interaction between the shields and the strata. Shield pressure data was back-analysed using a version of the Longwall Visual Analysis (LVA) software that has been extended to enable efficient load cycle analysis to be undertaken. The software outputs enabled the shield strata interactions to be characterised. The results of the analyses indicated that the major cause of the roof falls was high-level periodic weighting, resulting in periodic shield overload. Exploration borehole data was analysed to identify and characterise the overburden unit that was the likely cause of the shield overloading.