Sustainability website / Case Studies 2006 / Xstrata alloys / Xstrata Alloys adopts new approach to falls of ground

Xstrata Alloys adopts new approach to falls of ground

Falls of ground in underground operations have been identified as one of the principal causes of high potential risk incidents and fatalities at Xstrata Alloys and are responsible for half of recorded fatalities in South Africa mining. The elimination of roof falls in underground operations is a key element of the comprehensive fatality prevention programme implemented at Xstrata's South African operations over the past three years.

Geological understanding

'Dome' geological structures in the Bushveld Complex are not well understood and geological anomalies are a major cause of falls of ground in mines in this region. As a starting point, Xstrata Alloys hosted a strategy workshop on falls of ground in South Africa and invited eminent South African and Australian rock mechanics and mine safety specialists to join a range of Xstrata Alloys senior and line managers.

The purpose of the workshop was to examine the principal causes of roof falls, to determine why these incidents occurred more often in South Africa and to recommend actions that could be implemented to mitigate or eliminate the risk of further injuries from these incidents.

Managing the risk

This investigation marked a turning point for the South African mining industry, where falls of ground have previously been accepted as an inevitable consequence of the region's geology. Workshop participants addressed two key elements – ways to mitigate the immediate risk and ways to manage the residual risk.

During the workshop, a holistic approach considered factors such as mine design, mine planning, support systems, hazard plans, incident response and reporting. The workshop findings were critical of the traditional South African method of ground support and trials of modern resin bolts proved to be superior in providing an active support system.

Detecting anomalies

We have adapted ground penetrating radar (GPR) from the civil engineering industry and developed it for use in underground mining to detect anomalies in the hanging wall. The GPR technology provides an early warning of potential hazardous areas.

Xstrata Alloys also initiated a study through the Council for Scientific and Industrial Research, to gain a better understanding of the origin and formation of the Bushveld Igneous Complex – information which will benefit the South African mining industry as a whole.

Detecting anomalies

The workshop led to the introduction of a trigger action response plan (TARP), a system in use in Australian mines. The system concentrates on a more formalised reporting system and reaction to hazards, which relies on escalation of decision making. Conditions (triggers) for activating TARP were defined at a workshop for all levels of management through to front-line supervisors.

A TARP analysis is now part of everyday planning in Xstrata Alloys' mines. TARPs have been integrated into induction and training programmes, including computer simulated interactive training (see case study in this chapter) to emphasise experiential learning.

Independently audited

The system was reviewed by an independent, external auditor after 12 months to check on progress against targets and to ensure that the system maintains integrity. Results showed a 30% reduction in uncontrolled falls of ground since implementation and the system is operating effectively across all Xstrata Alloys' mine sites.