Rockburst support in shallow-dipping tabular stopes at great depth

Abstract

This paper investigates the unique problems associated with the design of rockburst support for shallow-dipping tabular excavations. These designs are particularly problematic when the stoping width is very small. In steep dipping orebodies, the layouts and mining methods can be selected to ensure that miners never enter the stopes. Only the access drives need to be protected by rockburst resistant support. In shallow-dipping orebodies, this problem is more difficult as miners enter the stopes and the entire hanging wall needs to be supported. A simple analytical model is used to investigate the implications for support design as a result of the convergence associated with the tabular geometry and the possibility of rocks being ejected during a rockburst. This illustrates that a support system is required that is initially stiff, but it should also be yieldable to survive the convergence in the back areas. By trial and error, the historic support solutions in the South African gold mines evolved into a system of timber packs and elongates to meet these requirements. When considering the three accepted key functions of modern rockburst support methodology namely, reinforce, retain and hold, the typical support design for these shallow-dipping orebodies does not meet all these requirements. The rock is highly fractured and fallouts occur between roofbolts during rockbursts as areal support is difficult to implement. Steel mesh is not used as it is often destroyed during cleaning operations. Solving this problem is of critical importance to ensure the viability of deep South African gold mines in future.

Stability of stope structure under different mining methods

“…For example, T. M. Ermekovtakes [7] mine engineering obtains the key parts of pillar instability in the goaf and then analyzes the goaf stability. Zhao et al [8][9][10], used FLAC 3D numerical simulation technology on the basis of the optimization of the mining scheme in Dajishan Tungsten Mine. They obtained the alternative and one mining schemes, which are further conducive to stope stability and can improve the stope production capacity.…”

Development of Rockburst Research: A Comprehensive Review

“…Cai et al put forward seven simple principles on rockburst support according to field experience, shown in Figure 11, for a design guide of rockburst support [30,173]. Kaiser et al summarized four functions required to provide a reliable support system for burst-prone conditions, shown in Figure 12, pointing out that support selection in burst-prone areas is a repeated process, which needs to be verified and modified based on field observation [192]. Kaiser et al summarized four functions required to provide a reliable support system for burst-prone conditions, shown in Figure 12, pointing out that support selection in burst-prone areas is a repeated process, which needs to be verified and modified based on field observation [191].…”

A Scientometric Review on Rockburst in Hard Rock: Two Decades of Review from 2000 to 2019

“…For example, Cai [44] proposed seven important principles of rockburst support, namely, the avoid rockburst principle, flexible/yielding support principle, address the weakest link principle, integrated system support principle, simplicity principle, cost-effectiveness principle, and observational construction principle. Malan and Napier [45] advanced a new design approach of rockburst support in shallow-dipping tabular stopes at great depths.…”