厚煤层无煤柱切顶成巷碎石帮变形机制及控制技术研究

发布时间：2018-12-18 06:34

【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。
[Abstract]:In order to solve the problem of gravel side control of automatic roadway in thick coal seam, the deformation mechanism and control technology of crushed stone side in thick seam roof cutting roadway were studied by means of mechanical analysis, numerical simulation and engineering test. The dynamic model is established to explore the mining height effect of gangue body impact in the course of roadway formation, and the stress mechanism and control focus of thick coal seam crushed stone side deformation are clarified, and then the multi-level control thought of dynamic pressure anti-flushing, slow pressure displacement and constant pressure stability control is put forward. The results show that when the mining height increases, the impact force and impact energy of the gangue body acting on the gangue structure will increase, thus forming the starting condition of transverse bending of the gangue retaining structure, resulting in large deformation under the action of roof pressure and lateral extrusion. The failure of the traditional gangue retaining structure; The main impact area is within 6 m behind the frame of the working face, and the self-moving dynamic pressure anti-scouring structure can be used to transform the individual flushing of the gangue structure into collective bearing pressure, which is helpful to dissipate the impact energy. The gangue body compaction stage is a slow compression process. The indoor loading test shows that the structure can maintain the dead load force and realize the synergistic deformation with the surrounding rock, thus reducing the damage rate. In order to further improve the overall stability of the gravel side, the wave-type multi-resistance protection cover structure is designed and manufactured. The field drawing test shows that the performance of the structure meets the requirements of support, and the farther the working face is lag, the more remarkable the effect of fixing the slope is. The results of field monitoring show that the deformation of surrounding rock is effectively controlled under the new technology, the deformation of gravel side is reduced by about 72%, and the damage rate of rock block structure is reduced by about 85%, which not only solves the problem of hard control of rock wall in roadway by cutting roof in thick coal seam, And the economic benefit is remarkable.
【作者单位】：中国矿业大学(北京)深部岩土力学与地下工程国家重点实验室;中国矿业大学(北京)力学与建筑工程学院;
【基金】：国家自然科学基金资助项目(51674265,51404248,51304210)~~
【分类号】：TD322.5

【相似文献】