First, we theoretically analyzed the solution to the large suspension span of the thick and hard roof in coal mining. Three- Zone pre-split blasting design in non-pillar coal mining for thick and hard roofs was proposed, based on the principles of rock mechanics. After field experiments, ...
As a major technique for realizing pillar-less mining in coal mines, it can improve the recovery rate of coal resources and prolong the mine's service life. It presents a superior method for preventing major disasters in mines such as rock bursts and gas outbursts [8]. At present, gob-...