中文摘要：

为解决厚煤层切顶卸压自动成巷碎石帮控制难题,采用力学分析、数值模拟和工程试验相结合的研究方法,对厚煤层切顶成巷碎石帮变形机制和控制技术进行深入研究。通过建立动力学模型,探索成巷过程中矸体冲击的采高效应,明确厚煤层碎石帮变形受力机制和控制重点,进而提出动压防冲、缓压让位和恒压稳控的多层次控制思路。研究表明,采高增大后,空区矸体作用在挡矸结构上的冲击力和冲击能均会增加,从而形成了挡矸结构横向弯曲的启动条件,在顶板下压和侧向挤压作用下产生大变形,造成传统挡矸结构失效;工作面架后6 m范围内为主要冲击区,架设自移式动压防冲结构可将挡矸结构的个体受冲转换为集体承压,有助于耗散冲击能;矸体压实阶段为缓压过程,提出采用抗弯性更强的滑移式让位护帮结构。室内承载试验表明,该结构可保持恒载力实现与围岩协同变形,从而降低损坏率;为进一步提高碎石帮整体稳定性,设计制造波式多阻护帮结构,现场拉拔试验表明该结构性能满足支护要求,滞后工作面越远,固帮效果越显著。现场监测结果表明,新技术下围岩变形得到有效控制,碎石帮变形降低了约72%,挡矸结构损坏率降低了约85%,不仅解决了厚煤层切顶成巷碎石帮难控问题,且经济效益显著。

英文摘要：

Gangue rib control is one of the biggest challenges for gob-side entry retaining formed by roof fracturing in thick coal seams. In this paper,the mechanism and control techniques for gangue rib deformations were systematically investigated using theoretical analysis,numerical simulation and field experimental methods. First,mechanical and numerical models were developed respectively to explore the dynamic impact behaviors of the gangue body for different mining heights. Based upon the obtained results,a multi-level control approach was proposed to address the instability problem of the gangue rib in thick coal seams. The results indicate that as the mining height increased,the impact force acted on the gangue prevention structure increased accordingly. The intense impact of the gangue body initiated the deformation of the conventional gangue prevention structure,and the roof sagging accelerated further its failure process. The severe impact area was within 6 m from the active mining panel,and an impact prevention device was designed to dissipate the impact energy. The variation of the lateral pressure was gentler within the compression area of the gangue rib. An individual support structure of sliding-type characterized by pressure release was designed and tested. Laboratory tests showed that the sliding-type structure coordinated effectively with the roof deformation,and thus improved massively its recycling utilization ratio. The anchor bolt of wave-type with multi-resistances was invented to further improve the monolithic stability of the gangue rib. Field pullout tests proved that the reinforcement effects of the structure were remarkable,especially when the structures were 60 m or far behind the active mining panel. The monitored results showed that the rib deformation decreased by appropriately 72% and the damage rate of the gangue prevention structures reduced by appropriately 85% after adopting the new approach. The proposed approach not only solved the rib control problems,but also brought about remarkab