Discontinuous Modeling of Roof Strata Caving in a Mechanized Longwall Mine in Tabas Coal Mine

Abstract

A better understanding of the interaction between shield supports, roof, and coal strata, along with the prediction of roof deformation and caving behavior is essential for successful longwall mining operations. The stability of a longwall face can be improved by caving of the roof strata, which can lead to decreasing the load on the powered supports and the magnitude of stress on the abutment pillar of the longwall face. This paper presents the application of the synthetic rock mass (SRM) numerical modeling approach for the simulation of the roof caving mechanism and the load on shield supports in a longwall coal mine in Iran. Using geological and geotechnical data from the mine, a two-dimensional SRM, based on the incorporation of a discrete fracture network into a bonded particle model, was used to simulate the coal seam and the jointed roof strata. The results of the numerical models were validated by comparing the span of first caving, caving height, and load on the support shields to field measurements, observations, and previous studies. The proposed numerical approach can be utilized as a reliable tool in the design and safe operation of a longwall panel with a better understanding of the caved, damaged, and deformed zones above it.