Effect of width of gallery of highwall mining on stability of highwall: A numerical modelling approach

Abstract

Owing to continuous increased demand for coal, along with existing mining methods, some novel methods are being looked for. Highwall mining is such a method where considerable quantity of coal blocked in the highwall can be extracted to a great extent. The major challenge in highwall mining is roof control along with the stability of highwall. This method was introduced in one of the opencast coal mines first time in India. A systematic study was taken up using numerical modelling approach to assess the influence of width of gallery of highwall on stability of highwall based on field investigations. The width of gallery was taken as 3.5, 4.25 and 5.0 m. It was found that the stress and strain was more in case of 5.0 m wide gallery compared with 3.5 m wide gallery and the stress and strain values were more at the end point of galleries compared with the starting points of the galleries. The factor of safety values were decreased as the width of gallery increased from 3.5 m to 5.0 m. 2014 Inderscience Enterprises Ltd.