Simulation of Old Surface and Underground Working for Assessment of Slope Stability

Abstract

Abstract Underground mining activities have potential influence on the surface slope stability. However, suitable attention has not yet been paid to these problems. The aim of this study is to analyze the possible influence of present and former mining activities on the selected set of physical and numerical model slope deformations in the Jharia Coalfield. In India coking coal seams are mainly confined to the Jharia coalfields of Jharkhand State. There are 19 coal seams, which were partially exploited earlier adopting the underground mining method. However, due to various complex geotechnical problems, it was not economically viable to continue the same method for coal extraction. A vast amount of coking coal remains unrecovered as they stand as pillars, collapsed materials, partings, barriers, etc. waiting to be extracted to meet the growing energy demand. In order to bridge the gap between the growing demands and supply, it is essential that the coal locked in the underground workings be recovered fully by implementing surface mining methods. As these new surface mines are planned in the areas which contain old surface and underground workings, the major problems will be the stability of slopes particularly when they meet the old underground workings, and the behavior of previously subsided material in the pit slopes. The present study was conducted to understand the effect of underground workings on the stability of new slopes using physical and numerical simulation. This paper emphasizes on the numerical simulation and further verification of the physical model results. The physical model results are well corroborated with numerical simulation study.