条带煤柱渐进破坏失稳灾变机理及性能提升

There are a large number of strip coal pillars, and the destabilization of the coal pillar will induce a variety of mine disasters. Some studies will be carried through site investigation, theoretical analysis, mechanical test, similar simulation, numerical simulation, field test and engineering feedback as follows. ①The abrupt failure mechanism and the stability-lost criterion of coal under long-term loading (not creep), the gradually destroy process and mechanism from the edge and mechanical properties in various parts after damage but not stability-lost of large size coal specimen. ②The relationship between the deformation and the stability of coal pillar, the difference between the coal pillar failure and stability-lost, and the evolution process from failure to stability-lost，the damage range and degree allowed in different conditions, stability-lost prediction method of strip coal pillar. ③The possibility and feasibility method of improve the coal pillar especially pillar edge's performance, and the different improve method would be establishment aimed at different disaster induced by pillar instability. ④The strip mining overburden structure models under different conditions, the disaster-caused mechanism and pattern of subsidence induced from pillar lost stability. The research will provide a new theoretical basis for stability-lost causing disaster mechanism of coal pillar in strip mining and safety protection, and has important significance in strip pillar remained reasonable, recovery rate enhancing, and disaster prevention induced from strip pillar stability-lost.

我国条带煤柱数量巨大，煤柱失稳会诱发多种矿山灾害。本课题采用现场调研、理论分析、力学试验、相似模拟、数值模拟、现场试验与工程反馈的方法开展如下研究。①与常规蠕变试验不同，从煤岩试样边缘渐进破坏进程和破坏后至失稳前的各部位力学特性入手，研究煤岩长期承载过程中的突变破坏机理和失稳判据。②煤柱变形与稳定性之间的关系，煤柱破坏与失稳的差别及破坏到失稳的演化过程，不同条件下煤柱的允许破坏范围和程度，建立煤柱变形预测煤柱失稳的预测方法。③以煤柱-覆岩作为整体研究提高煤柱性能尤其是煤柱边缘性能的可能性和可行性方法，初步确立针对条带煤柱诱发的不同灾害的煤柱性能提升方法。④研究不同条件下条带开采覆岩结构模型、条带煤柱失稳对地表塌陷的诱灾机理、规律、工程物理力学模型及防治方法。课题研究将为条带煤柱失稳灾变机理及安全防护提供新的理论基础，对条带煤柱的合理留设和提高回收率、煤柱失稳诱发的灾害防治具有重要意义。

我国条带煤柱数量巨大，煤柱失稳将诱发多种严重矿山灾害。本项目综合运用现场调研、理论分析、室内试验、相似模拟、现场测试等手段进行了条带煤柱渐进破坏失稳灾变机理及性能提升基础研究。研制了条带煤柱渐进破坏试验装置，进行了大尺寸原煤试样模拟煤柱长期承载试验，揭示了煤岩边缘破坏力学特征和长期承载突变破坏机理；分析了顶、底板岩性对条带煤柱破坏失稳影响机制，提出了将侧向变形阶跃增长作为煤柱破坏失稳前兆特征；提出了“顶板-煤柱”组合体试样宏观破坏起裂概念，明确了岩煤高比、加载速率对组合体试样强度、宏观破坏起裂及其渐进破坏影响规律：模拟了条带煤柱渐进破坏顺序，揭示了煤柱渐进失稳特征；研制了条带煤柱垂直变形监测装置、大量程高频率煤体横向变形监测方法和监测仪，发现了深部煤体横向变形的非连续、阶跃式、突变式特征；明确了干湿循环和酸碱浸泡作用对煤岩力学行为影响，从细观角度探讨了其作用机制；设计了注浆联合支护锚杆，提出了利用注浆联合支护锚杆提升煤柱性能技术方法以及充填墙提升煤柱性能的施工方法，给出了充填墙有效提升煤柱的合理强度和尺寸；研制了含柔性加载装置的三维综合模拟试验系统，明确了条带煤柱失稳引起的覆岩移动与地表变形规律、覆岩应力场演化规律；分析了基于条带开采的综合减沉技术方法，提出了条采采空区一体化综合治理技术方法。. 在本项目执行过程中，在《Rock Mechanics and Rock Engineering》、《岩石力学与工程学报》等国内外高水平期刊发表论文25篇，其中，SCI、EI收录论文21篇；出版《矿井特殊开采方法》学术专著1部；授权专利11项，其中发明专利9项；获国家科技进步二等奖1项、教育部科技进步二等奖1项、中国岩石力学与工程学会科技进步二等奖2项；项目负责人获山东省青年科技奖、高等学校采矿工程专业学生实践作品优秀指导教师奖2项。. 本项目研究将为条带煤柱失稳灾变机理及安全防护提供新的理论基础，对条带煤柱合理留设和提高回收率、煤柱失稳诱发的灾害防治具有重要意义。