薄基岩综放采场覆岩结构运动与控制研究(1).pdf

博士学位论文 薄基岩综放采场覆岩结构运动与控制研究 Tectonic Motion and Control of Overburden in Thin Bedrock Fully- mechanized Sublevel Caving Face 作 者黄汉富 导 师缪协兴教授 中国矿业大学 二○一二年十月 学位论文使用授权声明学位论文使用授权声明 本人完全了解中国矿业大学有关保留、使用学位论文的规定，同意本人所撰写 的学位论文的使用授权按照学校的管理规定处理 作为申请学位的条件之一，学位论文著作权拥有者须授权所在学校拥有学位论 文的部分使用权， 即 ①学校档案馆和图书馆有权保留学位论文的纸质版和电子版， 可以使用影印、 缩印或扫描等复制手段保存和汇编学位论文； ②为教学和科研目的， 学校档案馆和图书馆可以将公开的学位论文作为资料在档案馆、图书馆等场所或在 校园网上供校内师生阅读、浏览。另外，根据有关法规，同意中国国家图书馆保存 研究生学位论文。 （保密的学位论文在解密后适用本授权书） 。 作者签名 导师签名 年 月 日 年 月 日 中图分类号 TD325 学校代码 10290 UDC 密 级 公开 国家重点基础研究发展计划（973 计划）项目2013CB227900 国家自然科学基金委员会与神华集团有限责任公司联合资助项目（U1261201） 高等学校学科创新引智计划项目（B07028） 中国矿业大学 博士学位论文 薄基岩综放采场覆岩结构运动与控制研究 Tectonic Motion and Control of Overburden in Thin Bedrock Fully- mechanized Sublevel Caving Face 作 者 黄汉富 导 师 缪协兴 申请学位 工学博士 培养单位 矿业工程学院 学科专业 采矿工程 研究方向 岩层移动与绿色开采 答辩委员会主席 评 阅 人 二○一二年十月 论文审阅认定书论文审阅认定书 研究生 黄汉富 在规定的学习年限内， 按照研究生培养方案 的要求，完成了研究生课程的学习，成绩合格；在我的指导下完成本学 位论文,经审阅，论文中的观点、数据、表述和结构为我所认同，论文 撰写格式符合学校的相关规定， 同意将本论文作为学位申请论文送专家 评审。 导师签字 年 月 日 致致 谢谢 本论文是在缪协兴教授的悉心指导下完成的，没有缪协兴教授的指导、鼓励， 论文是不可能顺利完成的。师从三载，收获颇丰，感触亦深。导师优秀的做人品质， 严谨的治学态度，开拓创新的精神，高屋建瓴把握全局的能力，忘我的工作精神给 学生树立起潜移默化的典范作用，这也是导师传授给学生最宝贵的财富。在此，谨 向我的导师致以深深的敬意。 感谢茅献彪教授、曹胜根教授、柏建彪教授在论文选题和写作过程中给予关键 性的帮助。 感谢白海波教授在平时学业中的关心和支持。 感谢陈占清教授、王连国教授在论文写作方面给予的指导和帮助。感谢博士研 究生杜锋、姚邦华、张勃阳、陆银龙、罗吉安、郭晓倩，硕士研究生韦晓琪、戎虎 仁、焦阳等在数值模拟、理论分析以及实验方面给予的帮助；感谢吴洪老师在论文 排版方面所付出的辛勤劳动衷心感谢矿业学院领导和老师们多年来在学习和生活 上给予的关心、鼓励和帮助 在现场研究工作中，潞安矿业集团的同仁给予了大力支持，在此表示衷心的感 谢。 感谢家人为我学业的完成而付出的无私奉献。 感谢论文所应用文献的作者。 最后感谢在百忙之中评审本文并提出宝贵意见的各位专家教授 黄汉富 2012 年 10 月 I 摘摘 要要 我国薄基岩煤炭资源储量丰富，由于薄基岩开采覆岩结构运动力学机理研究不 足，开采实践中经常发生压垮支架事故，迫切需要对该地质条件下采动覆岩运动规 律进行系统研究，使其煤炭资源得到安全高效开采。本文以潞安矿区司马煤矿为研 究基地，针对该矿薄基岩、厚松散层、厚煤层的开采地质条件，综合运用理论分析、 数值计算、物理模拟、现场实测等方法，对薄基岩综放采场覆岩结构运动规律及支 架围岩关系进行了深入研究，取得了如下创新性成果 1 建立了薄基岩厚松散层综放开采覆岩运动的结构力学模型，揭示了薄基岩 与厚松散层条件下，覆岩“梁- 拱”复合平衡结构的形成及顶板不易发生周期性整体 切落的力学机理，并给出了覆岩复合平衡结构的稳定性判据。 2 薄基岩厚松散层综放开采条件下，工作面支架支护阻力与顶板下沉量 （Pl−∆）之间仍然满足双曲线关系，适当提高支架工作阻力可有效地控制顶板下 沉量，并给出了支架支护阻力、顶板下沉变形随基岩层岩性、厚度变化的规律，揭 示了薄基岩厚松散层综放开采的支架围岩作用关系，可为其工作面支架选型提供 理论基础。 3 依据潞安司马矿区的研究， 得到了薄基岩厚松散层综放开采矿压显现具有 初次来压和周期来压的步距短、顶板下沉速度大、静压大、动压小、动载系数小等 特点。并给出了来压步距、来压强度等随基岩层的岩性和厚度的变化规律。研究结 果可为薄基岩厚松散层综放采场的矿压显现预测及顶板管理提供依据。 4 依据薄基岩厚松散层条件下覆岩的成拱特征及载荷传递特点，将基岩层很 薄，采场矿压不明显、支架需承受拱内土体和基岩载荷，称为超薄基岩；对关键层 破断后能形成“砌体梁”结构，采场矿压明显，但来压强度弱，支架主要承受关键 层下方岩层和“砌体梁”下沉变形引起的载荷，称为薄基岩。并给出了相应开采方 案的选取原则。 本文的研究成果在司马矿薄基岩区采煤实践中得到了成功的应用，并为其它类 似薄基岩条件下开采提供了一定的理论研究和参考。 该论文有图 77 幅，表 24 个，参考文献 117 篇。 关键词关键词综放开采；薄基岩；厚松散层；覆岩运动；支架-围岩关系 III Abstract In Lu’an coal field which is characterized by rich coal resource with thin overlying rock mass, working face stents failure accidents caused by ground pressure often happened during the past mining practices, therefore, it is quite necessary to systematically study the overlying rock mass movement rule under this geological condition to make this coal resource mine safely and efficiently. In this paper, we take Sima coal mine in Lu’an coal field as the research base, and in view the geological condition of thin overlying rock, thick loose bed and coal seam in this coal mine, carry out deep investigation on the overlying rock mass movement rule and stents- surrounding rock mass relationship by systematically applying theoretical analysis, numerical simulation, physical simulation and practical measurement, obtaining the following innovative achievements 1 We build a structural mechanical model for thin overlying rock mass with thick loose bed under condition of fully mechanized mining, and revealed the ation of composite beam- arch balance structure as well as the mechanical mechanism that the roof will be hard to happen periodic failure under this geological condition, then we proposed the stability criterion condition for this composite structure. 2 Hyperbolic relationship between supporting force P and roof subsidence distance l∆ can still be satisfied under fully mechanized mining with thin overlying rock mass, so increasing the stent working force and effectively control the roof subsidence distance. Furthermore, we obtained the relationship between stent support force, roof subsidence deation and lithology, thickness of rock, and revealed the stent- surrounding rock interaction relationship, which can provide theoretical basis for stent choose when mining with thin overlying rock mass. 3 We obtained the ground pressure appearance character under fully mechanized mining with thin overlying rock mass and thick loose bed according to the research in Lu’an coal seam, that is to say, both the first weighting distance, and periodic weighting distance are small, roof subsidence velocity was large, and ground pressure is characterized by shorter weighting distance, larger static pressure, smaller dynamic pressure and dynamic load coefficient. This study can provide basis for ground pressure prediction and roof management under fully mechanized mining with thin overlying rock mass and thick loose bed 4 According to the structural characteristic and load transfer property of overlying IV rock mass under condition of thin overlying rock with thick loose bed, we defined rock mass which have characteristics include small thickness, less evident ground pressure and stent bear load from weight of rock and clay in arch as super thin rock mass. While for rock mass which have property that voussoir beam structure can after the key rock strata failed, ground pressure is obvious with weak strength, and stent bear load cased by subsidence deation of voussoir beam and weight of rock below key rock strata, we classified this type of rock as thin rock mass. Furthermore, we proposed the corresponding mining scheme and choose principle. The research results have been successfully applied in mining practice Sima coal mine with thin overlying rock mass, and can provide theoretical study and reference of other coal mine under this similar geological condition. There are 77 figures, 24 tables and 117 references in this paper. Key WordsFully mechanized mining；Thin overlying rock mass；Thick loose bed； Overlying rock mass movement；Stent- surrounding rock relationship V Extended Abstract Lu’an coal field is characterized by rich coal resource with thin overlying rock mass, and it is quite necessary to systematically study the overlying rock mass movement rule under this geological condition to make this coal resource mine safely and efficiently. In this paper, we take Sima coal mine in Lu’an coal field as the research base, and in view the geological condition that the minimum thickness of overlying rock mass is just 10m with a series of 2040m clay bed commonly existing in the bottom of loose bed, carry out deep investigation on the overlying rock mass movement rule and stents- surrounding rock mass relationship by systematically applying theoretical analysis, numerical simulation, physical simulation and practical measurement, obtaining the following innovative conclusion 1 We studied the distribution range, rock strata combination character and mechanical property of thin rock bed in Sima coal mine of Lu’an coal field. The drilling and experimental measurement indicate that, thin rock bed area in Sima coal mine main distribute in the east of coal field, and the whole 1st mining area and the most of 2nd mining area are located in thin rock bed area, where the thickness of overlying roc mass above 3 coal seam is commonly less than 40m, even less than 10m in some place; a clay bed with thickness of 2040m and liquidity index IL0 commonly develop at the bottom of loose bed, so their compressive strength is small and ing arch ability is very well; rock joints develop in weathering zone of thin rock bed area, so it is broken and has low strength, while for that in medium weathering zone, the rock strength is 2.815.24MPa, and the strength of intact rock mass is high, with a strength of 29.9378.03MPa for medium and fine sandstone, therefore, the rock strata in thin overlying rock mass area belong to relatively high strength rock. 2 We build a structural mechanical model for thin overlying rock mass with thick loose bed under condition of fully mechanized mining. The roof will composite beam- arch balance structure with periodic failure under this geological condition, and it is not prone to happening whole overlying rock mass drop, then we proposed the instability criterion condition for this composite structure based on the voussoir beam theory. 3 We studied the stent- surrounding rock relationship under mining condition of thin overlying rock mass and thick loose bed. Hyperbolic relationship between VI supporting force P and roof subsidence distance l∆ can still be satisfied under fully mechanized mining with thin overlying rock mass, so increasing the stent working force and effectively control the roof subsidence distance. Under different conditions that overlying rock mass thickness is larger than 40m, 2030m and less than 10m, the proper working force of stent should be 6000kN, 7000kN and 8000kN respectively. This study result can provide theoretical basis for stent choose when mining with thin overlying rock mass. 4 We analyzed the effect of immediate roof thickness and stents working force on ground pressure. When the mining height is 6.5m, the bigger of immediate roof is, the smaller of weighting distance will be, and the stents working force will become larger under more static load, and the weighting distance will tend to be steady when the thickness of immediate roof is more than 15m; if we increase the rated working force of stents, both the subsidence distance of roof coal seam and supporting pressure peak in front of working face will decrease, which can effectively increase the rib spalling accidents for soft coal seams. 5 We investigated the rule for overlying rock mass collapse and roof subsidence under condition that hard clay beds and rock strata have different thickness. The physical experiment results indicate that, rock strata subsidence distance will be larger when the hard clay bed thickness is smaller, and a dynamic self- stability structure can in the clay bed, which can absorb some load that overlying clay bed imposed on rock strata to some degree; the roof subsidence will obviously decrease with the increase of rock strata thickness, and under the condition that the whole thickness of clay bed and rock strata is 60m, the roof self- stability ability will increase with the growth of rock strata thickness, and it will be easier to steady voussoir beam structure at the same time, therefore, the height of collapse zone will decrease, while if the thickness of rock strata became smaller, it will have negative effect on the of steady structure, so the height of collapse zone will be large. 6 We proposed the definition of thin overlying rock mass and its classification . When structural key strata did not exist on rock mass beds, it should be classify to super thin rock mass, and under this condition, the ground pressure will be not obvious because clay bed will arch structure and the stents will just bear the load of weight of clay bed in arch and the overlying rock mass. While when there is a structure key strata or composite key strata ed by two rock strata in overlying rock mass, it will belong to the thin overlying rock mass, and under this condition, a voussoir beam VII structure will after the key rock strata failed, and the clay bed will a arch structure, then the stents will bear the load induced by subsidence of voussoir beam as well as the weight of rock mass below the key rock strata. The arch structure will as long as the thickness of clay bed is larger than 20m, and the thickness of rock strata will have a bit effect on the arch development under this condition. 7 The research disclosed the ground pressure appearance character when fully mechanized mining with thin overlying rock mass and thick loose bed. When fully mechanized mining in thin overlying rock mass area in Sima coal mine, roof subsidence velocity was large, and ground pressure is characterized by shorter weighting distance, larger static pressure, smaller dynamic pressure and dynamic load coefficient, that is to say, the data for the first weighting distance, periodic weighting distance, dynamic load coefficient are 2530m, 712m and 1.021.2 respectively. 8 We have successfully applied the research results in the coal mining of thin rock strata area in Sima coal mine. We studied and chose a suitable mining scheme based on analysis of geological conditions for Sima 1111 working face with thin rock strata, and carried out the reasonable type selection for stents. VIII IX 目目 录录 摘摘 要要.................................................................................................................................I 目目 录录..............................................................................................................................IX 图清单图清单...........................................................................................................................XIII 表清单表清单........................................................................................................................XVIII 变量注释表变量注释表.....................................................................................................................XX 1 绪论绪论................................................................................................................................ 1 1.1 研究背景及意义......................................................................................................... 1 1.2 国内外研究现状......................................................................................................... 2 1.3 主要研究内容及技术路线......................................................................................... 8 1.4 主要研究成果及创新点............................................................................................. 9 2 矿区采矿地质条件矿区采矿地质条件.......................................................................................................11 2.1 工程地质特征............................................................................................................11 2.2 矿区薄基岩区分布特征........................................................................................... 13 2.3 薄基岩区覆岩工程地质条件分析........................................................................... 15 2.4 本章小结.........................................................