MICRO SEISMIC MONITORING OF A BLOCK CAVE: LOGISTICS AND PERFORMANCE MEASUREMENT.

Micro seismic monitoring is the only established way to continuously and remotely monitor cave back progress in block cave mining. A seismic monitoring system represents a substantial capital investment. To maximise the return on this investment, it is important to have a clear understanding of how the system is going to be implemented and managed. A plan for this management should be in place before commissioning of the system. The return on investment in a seismic monitoring system can be framed by information on the performance of the cave and assessment of potentially damaging or harmful rock mass response to mining. This paper addresses the requirements of a system design, and the requirements of the subsequent management of the commissioning process. This includes aspects such as hardware redundancy and the experience of project managers. Following this, attention should be paid to the ongoing management of the seismic system. While advances in automatic processing have been made, a careful gap analysis needs to be performed to determine whether the results of automatic processing is at a sufficiently high confidence level to be used in day to day cave management. This paper discusses the results of a study of automatic processing and points out factors and potential pitfalls to be considered when assessing the locations of seismic events. Effective continuous seismic monitoring requires considerable commitments in terms of maintenance and human resources. This paper highlights and quantifies these commitments.