Simulation of the rock caving process using a mesh-free method

Authors: Karekal, S; Das, R; Mosse, L; Cleary, PW Download Paper

DOI https://doi.org/10.36487/ACG_rep/1002_35_Karekal

Cite As:
Karekal, S, Das, R, Mosse, L & Cleary, PW 2010, 'Simulation of the rock caving process using a mesh-free method', in Y Potvin (ed.), Caving 2010: Proceedings of the Second International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 509-521, https://doi.org/10.36487/ACG_rep/1002_35_Karekal



Abstract:
Understanding the caving process and material flow is fundamental to block and sublevel cave mining, and also longwall mining in sedimentary deposits. However, due to complexity of the structure of the rock mass and its behaviour, the caving process is rarely understood and cannot be described by simple mathematical models. Numerical methods that solve the governing partial differential equations with appropriate boundary conditions have been employed in modelling geomechanics problems. Notably, mesh-based finite element, boundary element and finite difference methods or combinations of these methods have been employed effectively for stress analysis for simulating rock excavations. However, when modelling caving processes, such as block caving, sublevel caving and longwall caving, the traditional mesh-based continuum approaches may fail to simulate such a process due to large material movement, fracture and fragmentation. This is mainly due to inaccuracies arising from mesh distortions resulting in spurious and ill conditioned models, and their deficiency to capture large material flows and fragmentations. In this paper, an application of a mesh-free method, called smoothed particle hydrodynamics (SPH), is demonstrated for simulating rock caving in a stratified deposit. The advantages for simulating caving processes using a meshfree numerical framework are highlighted. Two different examples are chosen, one with elastic-brittle material behaviour with a large yield strength (failure by brittle fracture) and the other with elasto-plastic material behaviour with a relatively lower yield strength to allow ductile deformation of the rock mass. The modelling results capture the mechanistic aspects observed in caving processes. It is shown that the large-scale deformation and the associated fracture processes in caving can be effectively simulated using SPH. In the authors’ knowledge, this work is the first attempt in demonstrating the application of a mesh-free method for simulating caving processes.

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