Kanowna Belle - evolution of seismicity with increasing depth in an ageing mine

摘要

Kanowna Belle went underground from the open pit in 1996. At the start of 2000 the decline had reached 950 m below surface and stoping was down to 740 m. Seismicity was starting to occur and by May 2000 a seismic system had been commissioned. Since then, seismicity has played an increasing role in risk management of the mine, both in respect to safety and production. Seismic events with increased damage potential only started to occur mainly below 970 m depth (below C-block). The increase in seismic risk has lead to the development and implementation of the Garford yielding bolt, the development of seismic management systems and the adaptation of the mining method and sequencing. With increasing depth and seismicity, development of the lower E-block the mine is now moving into a new environment where new support systems and seismic control systems are being developed and implemented. This paper highlights the need for long term planning strategies, good quality seismic and geology data collection, analysis and recognition of high risk zones and subsequent management systems that involve planning, analysis, support, exclusion zones and education/communication of the workforce.