Modeling and Analysis of Ground Subsidence Due to Underground Mining Using 3-d Numerical Techniques

Surface subsidence resulting from underground mining presents a significant challenge in mining engineering, potentially damaging surface structures, environmental concern, safety of personnel and causing substantial economic losses for the mine. An underground copper ore mine in India was taken as a case study to explore the subsidence caused by ore extraction during blast-hole stoping method of mining operations. In this study, different subsidence prediction modeling techniques (empirical, influence function, and theoretical/numerical/ analytical) have been outlined for assessing mining induced subsidence. A three-dimensional (3-D) numerical model was developed by the Finite element method (FEM) code strand7, was adopted, encompassing geologic complications such as joints and faults, connections between different lithologies, and the stoping sequence selected from the mine plans to investigate the mechanism of surface subsidence induced by underground mining. Further, the precision of predicting mine subsidence using 3-D numerical models remains a source of concern due to the extensive inputs required, primarily geological and geotechnical parameters. These parameters are required to improve the accuracy of mine subsidence prediction. Therefore, in-order to predict accurately using 3-D numerical Modeling technique, there is a need of Constraining of rock mass properties & in-situ stress using backward modeling. 3-D numerical models were developed for virgin state, current mining state, next 5 years mining state and next 10 years of mining state and their corresponding strain and displacement were reported in different directions