Title: Numerical analyses of the hangingwall failure due to sublevel caving: study case
Authors: Tomás Fernando Villegas Barba; Erling Nordlund
Addresses: Division of Mining and Geotechnical Engineering, Luleå University of Technology, 971 87 Campus University, Luleå, Sweden ' Division of Mining and Geotechnical Engineering, Luleå University of Technology, 971 87 Campus University, Luleå, Sweden
Abstract: The sublevel caving used in Kiirunavaara mine induces failure and subsidence of the hangingwall. Two sections of the mine were studied by means of numerical analyses. Numerical models were developed using finite element and discrete element codes. The former was applied to calculate the location of new failure surfaces in the hangingwall and to estimate the break angle when mining advances downwards. The latter was used to analyse the displacement path of the caved rock during draw and to determine its effect on the stability of the hangingwall and footwall. The models were calibrated using displacement monitoring data. The finite element analyses indicated that the break angle is almost constant for deeper mining levels but may change if the geometry of the orebody changes. The discrete element model showed the formation of a stationary zone along the footwall that reduces the magnitude of the shear forces during draw, increasing its stability.
Keywords: Kiirunavaara mine; hangingwall failure; sublevel caving; numerical analyses; mining subsidence; finite element analysis; FEA; discrete element method; modelling; break angle; displacement path; footwall stability; shear forces.
DOI: 10.1504/IJMME.2013.053168
International Journal of Mining and Mineral Engineering, 2013 Vol.4 No.3, pp.201 - 223
Received: 08 May 2012
Accepted: 09 Dec 2012
Published online: 02 Aug 2013 *