Abstract:
Rock support is an important aspect in underground mining to
stabilize the ground rock to provide a safe environment. As it directly influences
the safety, it is very important to evaluate the supporting system. As cost is a major
issue, it is important to reduce the support cost without compromising safety.
Bogala Graphite Lanka Ltd is an important vein-graphite supplier in the world
operating an underground mine using Over-hand-Cut-and-Fill mining method.
Steel supports, Rock bolts and timber supports are currently used for supports.
Eucalyptus Microcorys (Micro) is the main type of timber used for supports. The
objective was to find a cost effective type of support with the required level of
strength and durability in an underground environment. Rock mass classification
using Rock Mass Rating (RMR) was initially used to evaluate the intact rock. Several
timber types such as Eucalyptus Microcorys, Eucalyptus Grandis, Oil treated
Eucalyptus Grandis, Teak, Eucalyptus Camaldulensis and Hora were selected and
their mechanical properties were determined. Concrete beams and Steel beams were
also considered. From mathematical and cost analysis, it was evident that
Eucalyptus Camaldulensis satisfies the requirements. It was also found to be cost
effective than the existing type with a minimum cost saving of about 44%.
Citation:
Rathnapala, A.V.A.O.C., Perera, T.S.L.C., Hetttiarachchi, D.S.W., Gangatheepan, B., Chaminda, S.P., Daharmaratne, P.G.R., Senanayaka, I.P. (2010). Evaluation of existing timber supports in Bogala mine and proposals for alternatives. In N. P. Ratnayake, A.M.K.B. Abeysinghe, H.M.R. Premasiri & S. Karunaratne (Eds.), Proceedings of the 5th Annual Conference on Earth Resources for National Development (pp. 21-24). Department of Earth Resources Engineering, University of Moratuwa.