观文煤矿采动边坡稳定性及滑坡防治对策研究.pdf
论文题目观文煤矿采动边坡稳定性及滑坡防治对策研究 工程领域矿业工程 硕 士 生刘樟荣 (签名) 指导教师余学义 (签名) 赵兵朝 (签名) 李广成 (签名) 摘 要 山区地下煤层开采将引起边坡产生移动变形和应力重分布,导致边坡局部失稳破 坏,在一定条件下还可能诱发滑坡等地质灾害,严重威胁着矿区人居环境安全。观文煤 矿地表为典型的川南中山地貌,由于前期在反倾高陡山坡下对倾角为 29的 C11煤层和 C19煤层进行不合理的开采活动,现已诱发了较严重的采动滑坡现象,致使坡脚大量村 庄建构筑物损坏或被迫搬迁。 为了防范观文煤矿一采区东翼倾斜多煤层开采诱发滑坡灾害, 针对该区域特殊的地 质、地形和采矿条件,应用力学分析结合数值模拟方法计算分析了地下开采对边坡稳定 性的影响及开采扰动作用机制,并提出了采动崩滑灾害的防治对策和监测预警要点。主 要研究结论如下 建立了山区地表倾斜煤层开采覆岩断裂破坏的固支梁力学模型,计算得到 11902 和 11102 工作面开采后的覆岩最大断裂高度分别为 77.57m 和 100.34m;首次构建了采动深 层滑坡的初步判别模型,根据该模型判定 11902 工作面开采后将导致坡体下部发生采动 深层牵引式滑坡,进一步开采 11102 工作面后,将引起坡体中下部发生采动深层整体式 滑坡,并结合 FLAC3D数值模拟进行了验证和补充;根据数值模拟结果,分析得出了采 动浅层推移式滑坡、采动深层牵引式滑坡和采动深层整体式滑坡的演化模式,并应用尖 点突变理论分析了开采扰动作用机制;提出了留设边界煤柱、调整区段回采顺序及矸石 自溜充填开采等减灾开采方法,并应用数值模拟验证了减灾效果,同时提出了采动滑坡 灾害的地表防治措施和监测预警要点。 研究成果对类似条件下的山区地表采动边坡稳定 性问题及防灾减灾相关理论的深入发展具有一定的借鉴意义和较高的学术价值。 关 键 词山区地下开采;边坡稳定性;采动滑坡;判别模型;防治对策 研究类型应用研究 万方数据 Subject Research on Mining Slope Stability and Prevention Measures of Mining–induced Landslide in Guanwen Coal Mine Specialty Mining Engineering Name Liu Zhangrong Signature Instructor Yu Xueyi Signature Zhao Bingchao Signature Li Guangcheng Signature ABSTRACT The coal exploitation under mountain areas results in the deation, stress redistribution and local destabilization failure of slope, and probably induces geological hazards such as landslides under certain conditions, posing a serious threat to the human settlement security in the mining area. As an example, due to the er irrational exploitation activities to the C11 and C19 coal seam with a dip angle of 29 degrees under a anti-dip high-steep slope, a large number of village buildings or structures involving Guanwen coal mine, which locates in southern Sichuan province and possess a typical medium mountain land, has been damaged or been forced to relocate. In order to prevent landslides caused by inclined multiple coal seams mining in east side of panel one of Guanwen coal mine, in view of its special geological, topography and mining conditions, the influence of underground mining on the slope stability and the mining disturbance mechanism are analyzed combining mechanical calculation and numerical simulation , and some prevention measures and main points of monitoring and early warning of mining-induced landslide are proposed. The main research results are as follows A clamped-clamped beam mechanical model of the mining overburden fracture in inclined coal seam under mountain is established, and accordingly the maximum overburden fracture height of face 11902 and 11102 are respectively worked out to be 77.57m and 100.34m. A preliminary discrimination model of mining deep landslide is first constructed. According to the model, there appears mining deep retrogressive landslide in the lower part of the slope due to the extraction of face 11902, and mining deep integral landslide in middle and lower part of the slope due to the following extraction of face 11102. This is verified and supplemented by FLAC3D numerical simulation.The evolution model of mining shallow 万方数据 thrust-type landslides, mining deep retrogressive landslide and mining deep integral landslide is analyzed according to the result of numerical simulation, and the mining disturbance mechanism is analyzed based on cusp catastrophe theory. Several disaster reduction mining s such as setting boundary pillar, adjusting the mining sequence of sections and gangue self-slide filling mining are put forward, and their disaster reduction effect is verified by numerical simulation. Simultaneously, the surface prevention measures and the main monitoring-warning points of landslide are proposed. The research results of this thesis provide certain reference significance and great academic value to mining slope stability problem and further development of disaster prevention and reduction mining theory in mountainous area under similar conditions. Keywords Underground mining in mountain area; Slope stability; Mining-induced landslide; Discrimination model; Prevention measures Thesis Application research 万方数据 目录 I 目 录 1 绪论 ........................................................................................................................................ 1 1.1 研究背景及意义 .......................................................................................................... 1 1.1.1 研究背景 ............................................................................................................ 1 1.1.2 研究意义 ............................................................................................................ 3 1.2 采动滑坡灾害国内外研究现状 .................................................................................. 4 1.2.1 国外研究现状 .................................................................................................... 4 1.2.2 国内研究现状 .................................................................................................... 5 1.3 研究内容及研究目标 .................................................................................................. 8 1.3.1 研究内容 ............................................................................................................ 8 1.3.2 研究目标 ............................................................................................................ 8 1.4 研究方案及技术路线 .................................................................................................. 9 2 地质采矿条件及采动滑坡灾害特征分析 .......................................................................... 11 2.1 交通位置及自然地理 ................................................................................................ 11 2.1.1 交通位置 .......................................................................................................... 11 2.1.2 自然地理 .......................................................................................................... 11 2.2 地层岩性与地质构造 ................................................................................................ 13 2.2.1 地层岩性 .......................................................................................................... 13 2.2.2 地质构造 .......................................................................................................... 15 2.3 煤层赋存特征及矿井采掘现状 ................................................................................ 15 2.3.1 煤层赋存特征及顶底板条件 .......................................................................... 15 2.3.2 矿井采掘现状 .................................................................................................. 16 2.4 采动滑坡特征分析 .................................................................................................... 17 2.5 本章小结 .................................................................................................................... 18 3 自然边坡稳定性及主要影响因素分析 .............................................................................. 19 3.1 边坡的类型与破坏形式 ............................................................................................ 19 3.2 几种常用的极限平衡分析法 ..................................................................................... 20 3.2.1 简化 Bishop 法 ................................................................................................. 21 3.2.2 简化 Janbu 法 ................................................................................................... 23 3.2.3 Spencer 法 ......................................................................................................... 24 3.2.4 GLE/Morgenstern-Price 法 ............................................................................... 25 3.3 基于极限平衡法的边坡稳定性分析 ........................................................................ 25 3.3.1 Slide 软件概述 .................................................................................................. 25 万方数据 目录 II 3.3.2 研究区域自然边坡的稳定性 .......................................................................... 26 3.4 影响边坡稳定性的主要因素 .................................................................................... 29 3.5 本章小结 .................................................................................................................... 32 4 覆岩破断力学模型及其对边坡稳定性的影响 .................................................................. 33 4.1 倾斜煤层开采覆岩断裂破坏的一般规律 ................................................................ 33 4.2 倾斜煤层开采覆岩断裂破坏的力学模型 ................................................................ 33 4.2.1 水平地表倾斜煤层开采覆岩断裂破坏的力学模型 ...................................... 34 4.2.2 山区地表倾斜煤层开采覆岩断裂破坏的力学模型 ...................................... 36 4.3 研究区域内各工作面采动覆岩断裂破坏的力学分析 ............................................ 38 4.4 采动覆岩断裂破坏对边坡稳定性的影响 ................................................................ 41 4.4.1 采动深层滑坡的初步判别模型 ...................................................................... 41 4.4.2 采动覆岩断裂破坏对漏风垭天马山北侧边坡稳定性的影响 .................. 42 4.4.3 采动覆岩断裂破坏对天马山大石王东侧边坡稳定性的影响 .................. 44 4.5 本章小结 .................................................................................................................... 45 5 采动边坡稳定性的数值模拟研究 ...................................................................................... 46 5.1 采动边坡稳定性问题的特殊性 ................................................................................ 46 5.2 数值模型的建立 ........................................................................................................ 47 5.2.1 计算区域的地形地物及开采特征 .................................................................. 47 5.2.2 模型参数与边界条件 ...................................................................................... 48 5.3 开采 11902 工作面对边坡稳定性的影响 ................................................................ 50 5.3.1 移动变形特征 .................................................................................................. 50 5.3.2 应力应变特征 .................................................................................................. 51 5.4 开采 11102 工作面对边坡稳定性的影响 ................................................................ 53 5.4.1 移动变形特征 .................................................................................................. 53 5.4.2 应力应变特征 .................................................................................................. 54 5.5 采动滑坡灾害的演化模式 ........................................................................................ 56 5.6 开采对边坡稳定性的扰动作用机制分析 ................................................................ 57 5.6.1 尖点突变模型的基本理论 .............................................................................. 58 5.6.2 开采对边坡稳定性的扰动作用机制 .............................................................. 59 5.7 本章小结 .................................................................................................................... 62 6 采动滑坡灾害的防治对策 .................................................................................................. 63 6.1 采动滑坡灾害的减灾开采方法 ................................................................................. 63 6.1.1 留设边界保护煤柱 .......................................................................................... 63 6.1.2 调整区段回采顺序 .......................................................................................... 64 万方数据 目录 III 6.1.3 矸石自溜充填开采 .......................................................................................... 65 6.2 采动滑坡灾害的地表防治措施 ................................................................................. 67 6.2.1 地裂缝、塌陷坑及危岩处理 .......................................................................... 68 6.2.2 排水措施 .......................................................................................................... 69 6.2.3 锚固及支挡工程 .............................................................................................. 69 6.2.4 植被护坡工程 .................................................................................................. 70 6.3 采动滑坡灾害的监测预警要点 ................................................................................ 71 6.4 本章小结 .................................................................................................................... 72 7 结论与展望 .......................................................................................................................... 73 7.1 结论 ............................................................................................................................ 73 7.2 展望 ............................................................................................................................ 74 致谢 .......................................................................................................................................... 75 Acknowledgment .................................................................................................................... 76 参考文献 .................................................................................................................................. 77 附录 .......................................................................................................................................... 84 万方数据 1 绪论 1 1 绪论 1.1 研究背景及意义 1.1.1 研究背景 四川省古叙煤田开发股份有限公司观文煤矿位于四川盆地与云贵高原过渡地带的 古蔺县观文镇。井田范围内山峦叠嶂,沟谷纵横,奇峰异石,地形崎岖,为典型的川南 山地地貌。地表最低点与最高点的相对高差达 895.90m,一般高差 500~700m,属构造 剥蚀成因的中山地形。矿井设计生产能力为 1.2Mt/a,当前主采川南煤田古叙矿区的 C11 煤层和 C19煤层,采用斜井多水平开拓,采区上下山双翼准备,单一煤层走向长壁综合 机械化采煤,全部垮落法处理采空区。在一采区东翼范围内,C11煤层平均厚度 3.63m, C19煤层平均厚度 1.65m,两层煤平均层间距 50.13m,平均倾角均为 29,煤层顶板易 冒落难管理。 近年来,随着观文煤矿生产建设活动的推进,矿区地表不良地质现象日益凸显。据 实地调查统计,一采区范围内的观文镇复兴一社、共和三社出现了 1 处表土滑动、1 处 崩塌、1 处地表沉陷、11 条地裂缝以及 12 处水井水位下降甚至断水等一系列不良地质 现象,部分村民房屋和院坝出现墙体开裂和地基下沉。二采区范围内的复兴二社、三社 发现 13 条缝宽 5~50cm 的地裂缝,部分村民的房屋和院坝出现了不同程度的开裂、下 沉和垮塌,其中 6 户房屋倒塌。此外,在二采区观文阁山顶发现了 2 条缝宽 5~20cm 的 地裂缝,山体出现向下滑移的迹象。这些不良地质现象直接威胁着观文煤矿工业场地、 观文镇街道及村庄民房的安全,引发了矿企与当地群众的尖锐矛盾,因此亟需对其加以 研究并在后续采掘工程及地面工程中采取科学合理的防治对策。 如图 1.1 所示,本文以观文煤矿一采区东翼为研究区域,该区域的平面尺寸大小为 1350m900m,地表峰峦叠嶂、沟壑纵横、地势崎岖,自西向东分布有园子头东峰 1386.0m、漏风垭西峰1356.8m、天马山西峰1415.1m、天马山东峰1416.0m 和大石王西峰1368.5m等 5 座山峰。在漏风垭西峰北侧坡谷较平缓处建有观文煤矿工 业场地1175m及零散分布的福来山村庄民房;在天马山东峰北侧硬化水泥公路两侧分 布有付家垇口村庄民房及观文煤矿家属区,东北方向分布有观文中学、观文镇、水口寺 等城镇民房;在大石王西峰东侧沟谷公路两侧分布有大石王城镇民房。 漏风垭西峰、天马山西峰和天马山东峰山脊线北侧山体构成“漏风垭天马山北侧 边坡” ,天马山东峰和大石王西峰山脊线东侧山体构成“天马山大石王东侧边坡” ,这 两个边坡即为本文的研究对象。 万方数据 西安科技大学全日制工程硕士学位论文 2 图 1.1 研究区域工作面布置及地形地物对照图 园子头东园子头东峰峰 漏风垭西峰漏风垭西峰 天马山西峰天马山西峰 天马山东峰天马山东峰 大石王西峰大石王西峰 工业场地工业场地 福来山居民福来山居民 付家垇口居民付家垇口居民 家属区家属区 11902 11102 漏风垭漏风垭天马山天马山 山脊线山脊线 11104 11906 11904 11106 天马山天马山大石王大石王 山脊线山脊线 C11 煤层露头线煤层露头线 C19 煤层露头线煤层露头线 观文镇观文镇 本文研究区域 大 石 王 居 民 大 石 王 居 民 观文中学观文中学 29 万方数据 1 绪论 3 研究区域内共设计布置 6 个工作面, 主要开采 3.63m 厚的 C11煤层和 1.65m 厚的 C19 煤层, 煤层倾角 29。 其中 11902 和 11102 工作面位于漏风垭天马山北侧边坡正下方, 各工作面开切眼位于天马山大石王东侧边坡正下方。 在该两边坡下开采 C11煤层和 C19 煤层,特别是开采 11902 和 11102 工作面后,一旦诱发采动崩塌、滑坡等地质灾害,将 对山坡谷底的观文煤矿工业场地、村