Abstract A non-pillar coal-mining technology with an automatically formed entry is proposed, which reduces the waste of coal resources and the underground entry drivage workload. Three key techniques in this technology cooperate to achieve automatic formation and retaining of the gob-side entry, and to realize non-pillar mining. Constant-resistance large deformation (CRLD) support ensures the stability of the entry roof; directional presplitting blasting (DPB) separates the entry roof and the gob roof; and a blocking-gangue support system (BGSS) integrates the caved rock material as an effective entry rib. An industrial test was conducted to verify the engineering effects of these key techniques. The field application results showed that the retained entry was under the pressure-relief zone due to the broken-expansion nature of the caved rock mass within the DPB height. After going through a provisional dynamic pressure-bearing zone, the retained entry entered the stability zone. The final stable entry meets the requirements of safety and production. The research results demonstrate the good engineering applicability of this technology. By taking the framework of the technology design principles into consideration and adjusting the measures according to different site conditions, it is expected that the proposed non-pillar coal-mining technology can be popularized on a large scale.

中文翻译：

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一种具有自动形成入口的创新无柱采煤技术：案例研究

摘要 提出了一种自动形成入口的无柱采煤技术，减少了煤炭资源的浪费和井下掘进工作量。该技术中的三项关键技术配合，实现沿空空巷自动形成和保留，实现无柱开采。恒阻大变形（CRLD）支撑，保证入口屋顶的稳定性；定向预裂爆破（DPB）将入口顶板和采空区顶板分开；和阻塞脉石支撑系统（BGSS）将塌陷的岩石材料作为有效的入口肋。通过工业试验验证了这些关键技术的工程效果。现场应用结果表明，由于DPB高度内塌陷岩体的破胀性质，滞留入口位于卸压带之下。通过临时动承压区后，保留的入口进入稳定区。最终稳定进入符合安全生产要求。研究结果证明了该技术具有良好的工程适用性。通过综合考虑技术设计原则的框架，根据不同现场情况调整措施，有望实现所提出的无柱采煤技术的大规模推广。最终稳定进入符合安全生产要求。研究结果证明了该技术具有良好的工程适用性。通过综合考虑技术设计原则的框架，根据不同现场情况调整措施，有望实现所提出的无柱采煤技术的大规模推广。最终稳定进入符合安全生产要求。研究结果证明了该技术具有良好的工程适用性。通过综合考虑技术设计原则的框架，根据不同现场情况调整措施，有望实现所提出的无柱采煤技术的大规模推广。