This article introduces a new non-pillar coal mining technology (i.e., Gob-side Entry Retaining by Roof Cutting (GERRC)) under the condition of thick and hard roofs. First, we theoretically analyzed solution to large suspension span roof in mining. Three-Zone pre-split blasting design for roofs was proposed, based on principles rock mechanics. After field experiments, successfully applied huge ...

In response to the large-scale instability failure problem of designing coal pillars and support systems for gob-side entry driving (GSED) in high-stress soft seams deep mines, main difficulties surrounding rock control GSED were analyzed. The relationship between position roof breaking line, together with width limit equilibrium zone a reasonable size pillar, quantified through theoretical cal...

Underground coal mining continues to evolve in the U.S., and more reserves are being mined under deeper cover, with worse roof, or with interactions from previous workings. At the same time, the mining community is responding to higher safety standards and intense competitive pressures. The need for effective ground control design has never been greater. Ground control safety issues that have b...

To guarantee the stability of a building complex above planned mining district with ultrasoft strata, strip technology (SMT) was applied to control displacement and deformation caused by underground exploitation. This study attempts design reasonable pillar width establish stable pillar-support (PS) system composed ground buildings coal pillars underneath. Based on stratigraphic structure strat...