Arlington, VA — A new video from the Mine Safety and Well being Administration is meant to boost consciousness of pillar collapses in underground mines.
Though no accidents resulted from 4 huge pillar collapses recorded by the company since October 2020, the video urges mine staff and operators to take motion to judge and handle hazards widespread to pillar collapse incidents.
Throughout the six-minute video, MSHA shows diagrams detailing how pillar collapses happen in addition to footage of an air blast ensuing from a pillar collapse in August.
The act of benching, or mining the ground, adjustments the general dimensions of help pillars and infrequently is a root reason for pillar collapses.
“After the floor is mined, pillars are taller than when they were initially developed, but their width remains the same,” the video states. “The result is a tall, slender pillar with a decreased ability to support the roof. The stability of tall, slender pillars can be further impacted by inadequate survey control, poor blasting techniques, weathering or geologic features.”
Pillars with an hourglass form or displaying current rock spalling from the rib are at specific risk of collapse, the company says. Risks to miners embrace a fall of the roof, smaller rock falls and air blasts.
“Miners may be exposed to an air blast at great distances from the location of the pillar collapse,” MSHA says, citing haul roads, journey methods, crushers, outlets, portal entrances and explosives magazines as areas that doubtlessly could also be affected.
Moreover, sink holes generally outcome from pillar collapses and may pose hazard to floor miners working above the collapsed space.
MSHA advises mine staff to pay attention for falling rock or sounds of the bottom working, and report any considerations to mine administration or the native MSHA workplace.
“MSHA will be reaching out to mine operators and discussing these hazards and best practices with miners,” the video states.