Stability analysis of shafts in the proposed deepening in Zawar Mines, HZL: A Case Study

摘要

'S' factor is very important for operational existence of underground mines i.e. Stability, Stress, Shaft, Stoping and Safety. These factors depend on geology and in situconditions around the excavatedzone. Major geological discontinuities and uncertainties in geology, sometimes have a deleterious effect on the stability and safety of the mine. Therefore, detailed analysis of geological data coupled with stress analysis is necessary before recommending remedial measures. This paper presents the results of 3D numerical modelling and geological studies to assess the stability of four shafts, each of Central Mochia, Balaria, West Mochia and Zawarmala under Zawar group of mines operated by Hindustan Zinc Ltd. (HZL) of Vedanta Group, when deepened by 300m from the existing bottom level. Rock Mass Rating (RMR) and Geological Strength Index (GSI) were calculated on the basis of the available data at the mine site. Shafts were modelled using 3D discontinuum software (3DEC) [1] to understand the rock mass behavior and stress distribution around them. Various geological and geotechnical parameters were incorporated into the three dimensional model. Effect of nearby open stopes on the stability of the shaft was also considered in this study. The results showed no sign of abnormal displacement and accumulation of stresses at the existing shaft and the proposed deepened part of the shafts.