ABSTRACT: While hazards resulting from spontaneous heating, gas migration, explosions and flooding remain a major threat to the safety and productivity of underground mines, specific research into overpressure ratings and integrity testing of ventilation control devices (VCDs), bulkheads and dams remains relatively limited.
Given the difficulty to conduct field tests in operational environments, as well as the high variability of mine ventilation and geology conditions, the performance of ventilation control devices poses a significant challenge for underground mines.
In Australian studies, a computational engineering model has been developed to determine overpressure-rating standards for ventilation control and geology consolidation devices.
With data obtained from live blast testing in an underground mine in Western Australia, explosion dynamics and structural responses of full size ventilation control devices (VCDs) were analysed and used to calibrate a 3-dimensional finite-element computer model of a VCD subjected to blast loading. This calibration began by transferring actual pressure distribution contours from the testing and then compared axial, bending and shear stresses as well as total loading and deflection between various configurations. The results were then used to develop a design tool that can assess installation requirements for a combination of height, width, over pressure, head of water and a factor of safety for individual sites.
With the resultant computational model now widely utilised in underground mines, testing parameters have been extended to determine engineering requirements for water-retaining bulkheads and dam walls, where non-uniform pressure and long-term water resistance are critical to mine safety.
As the mining industry strives to develop a national standard for conformance of ventilation control and geology consolidation devices, the development of new methods of
determining specifications not only aids the design of innovative ventilation management strategies, but also provides the industry with the assurance of knowing that their ventilation control devices increase the safety factor in underground mine environments.