多年冻岩露天煤矿边坡稳定性演化规律研究.pdf

万方数据 万方数据 万方数据 西安理工大学博士学位论文 ii 本研究得到冻土工程国家重点实验室开放基金（SKLFSE201311）和中煤科工集团西 安研究院有限公司科技创新基金（2012XAYCX020）的资助。 万方数据 万方数据 西安理工大学博士学位论文 iv 3 The mechanical properties and freezing and thawing deterioration rules of three typical rock samples were studied systematically by the freeze-thaw cycle test. The mechanism of rock freezing and thawing damage was revealed by the CT mesoscopic monitoring, sound wave and microfracture test during the freezing and thawing process. A model of typical rock freezing and thawing deterioration was established by microfracture expansion factor. 4 Based on the well-known rock mass strength criterion of Hoek-Brown at home and abroad, combined with the characteristics of frozen rock slope engineering, a new “freezing and thawing disturbance coefficient“ was proposed to replace“Blasting disturbance coefficient“ which is the of no longer meaningful in this field. It can fully reflect the timeliness of freezing and thawing process that the deterioration of rock mass gradually increases with the increase of freezing and thawing time. The calculated law of rock mass intensity was consistent with the law obtained by the experiment, which is proved that the reliability and validity of freezing and thawing strength criterion of rock mass. 5 Acording to the monitoring data of the frozen rock slope in the Muli Coal Mine, the 3G2000 three coupling analysis software developed by the team was calibrated. On the basis of the software and FLAC 3D plat, the numerical simulation experiment was carried out to study the main influencing factors of long-term stability of frozen rock slope ambient temperature, slope water content, conditions of slope water supply, the number of freezing and thawing cycles, the geometric characteristics of the slope and so on. And on this basis, the paper put forward the and standard of safety uation of frozen rock slope. Key words rock freezing and thawing deterioration; damage law and model; microfracture expansion factor; slope stability; open-pit coal mine; freezing - thawing cycle; Hoek-Brown strength criterion; freezing – thawing disturbance degree 万方数据 目录 I 目目 录录 摘 要 .......................................................................................................................i Abstract .................................................................................................................... iii 1 绪论 ................................................................................................................... 1 1.1 研究背景 ............................................................................................................................................. 1 1.1.1 世界及我国煤炭资源开发状况 .............................................................................................. 1 1.1.2 高海拔多年冻土区的宏观特征 .............................................................................................. 3 1.1.3 高海拔多年冻土区露天煤矿边坡特征 .................................................................................. 4 1.2 冻岩及冻岩边坡研究现状 ................................................................................................................. 7 1.2.1 冻融环境中冻岩性态变化规律研究 ...................................................................................... 7 1.2.2 冻融环境中冻岩边坡稳定性研究 ........................................................................................ 13 1.2.3 冻岩及冻岩边坡尚需研究的科学问题和发展趋势 ............................................................ 14 1.3 本文研究对象及选题依据与意义 ................................................................................................... 15 1.3.1 本文研究对象 ........................................................................................................................ 15 1.3.2 选题依据 ................................................................................................................................ 15 1.3.3 选题意义 ................................................................................................................................ 17 1.4 研究内容及技术路线 ....................................................................................................................... 18 1.4.1 研究思路与研究内容 ............................................................................................................ 18 1.4.2 研究技术路线和方法 ............................................................................................................ 19 2 高海拔多年冻土区冻岩赋存特征研究 ......................................................... 21 2.1 聚乎更矿区及冻岩边坡概况 ........................................................................................................... 21 2.1.1 聚乎更矿区自然地理概况 .................................................................................................... 21 2.1.2 露天矿边坡的特征 ................................................................................................................ 22 2.2 冻土（岩）概况 ............................................................................................................................... 23 2.2.1 区域冻土（岩）概况 ............................................................................................................ 23 2.2.2 矿区冻土（岩）概况 ............................................................................................................ 24 2.3 边坡冻结岩层与水冰特征 ............................................................................................................... 26 2.3.1 冻结态的采场边坡地层含冰特征 ........................................................................................ 26 2.3.2 冻结与消融态的边坡地层特征 ............................................................................................ 28 2.3.3 采场边坡地层消融的水冰特征 ............................................................................................ 30 2.4 冻岩边坡特征及其表观灾害 ........................................................................................................... 31 2.4.1 边坡及其灾害特征 ................................................................................................................ 31 2.4.2 边坡特征成因及灾害影响因素 ............................................................................................ 32 2.5 冻岩边坡研究的代表性体元 ........................................................................................................... 35 2.6 本章小结 ........................................................................................................................................... 37 3 冻融环境中岩石导热特性及水热力耦合机理分析 ..................................... 39 3.1 岩石冻融循环过程中的温度场特性 ............................................................................................... 39 万方数据 西安理工大学博士学位论文 II 3.1.1 岩石冻融过程中的温度平衡室内试验 ................................................................................ 40 3.1.2 热量传递与温度平衡理论分析 ............................................................................................ 45 3.1.3 岩石冻融循环过程中的介质与环境效应............................................................................. 49 3.2 岩石冻融环境中的结构特征变化试验 ........................................................................................... 52 3.2.1 试样制备与试验方案 ............................................................................................................ 52 3.2.2 试验结果与分析 .................................................................................................................... 53 3.3 冻融条件下岩石热力耦合分析 ....................................................................................................... 55 3.3.1 岩石热力耦合基本假定 ........................................................................................................ 55 3.3.2 饱和岩石冻融循环过程微裂隙扩展 .................................................................................... 56 3.3.3 饱和岩石微裂隙扩展多场耦合效应 .................................................................................... 58 3.4 本章小结 ........................................................................................................................................... 63 4 冻融环境中岩石力学性质变化规律及宏观机理 ......................................... 65 4.1 岩石冻融环境中岩石的强度试验分析 ........................................................................................... 65 4.1.1 室内冻融环境中岩石压缩试验 ............................................................................................ 65 4.1.2 现场冻融环境中岩石点荷载试验 ........................................................................................ 69 4.2 岩石冻融环境中的结构特征变化试验 ........................................................................................... 71 4.2.1 室内冻融环境中岩石声波波速试验 .................................................................................... 71 4.2.2 岩石冻融环境中的物理参数变化试验分析......................................................................... 74 4.3 岩石冻融损伤模型 ........................................................................................................................... 76 4.3.1 饱和岩石冻融的微裂隙率特征 ............................................................................................ 76 4.3.2 饱和岩石冻融强度损伤 ........................................................................................................ 76 4.3.3 强度损伤模型与规律 ............................................................................................................ 79 4.3.4 冻融损伤试验结果及模型验证分析 .................................................................................... 81 4.4 冻融环境中岩石结构与物理力学特性响应的本质 ....................................................................... 83 4.4.1 冻融环境对岩石的环境和荷载属性 .................................................................................... 83 4.4.2 冻融环境中岩石的特性指标响应 ........................................................................................ 84 4.5 本章小结 ........................................................................................................................................... 85 5 冻融环境中边坡岩体的劣化规律与损伤模型 ............................................. 87 5.1 岩体的宏观结构特征与理想模型 ................................................................................................... 87 5.1.1 岩体的宏观结构 .................................................................................................................... 87 5.1.2 岩体的结构特性及基本假定 ................................................................................................ 87 5.2 岩体冻融损伤模型 ........................................................................................................................... 88 5.2.1 Hoek-Brown 强度准则剖析 ................................................................................................... 89 5.2.2 冻融岩体强度分析 ................................................................................................................ 92 5.3 岩体冻融损伤的 Mohr-Coulomb 准则解释 .................................................................................... 98 5.3.1 Hoek-Brown 与 Mohr-Coulomb 强度准则 ............................................................................. 98 5.3.2 冻融环境中 Mohr-Coulomb 强度准则参数 ......................................................................... 99 5.4 本章小结 ......................................................................................................................................... 100 6 冻岩边坡稳定性分析与评价研究 ............................................................... 103 6.1 冻融条件下岩质边坡稳定性分析方法 ......................................................................................... 103 6.1.1 水冰相变简化算法 .............................................................................................................. 103 6.1.2 三场耦合简化算法 .............................................................................................................. 106 万方数据 目录 III 6.1.3 岩体热力学参数研究 .......................................................................................................... 108 6.1.4 岩体的初始条件及边界条件研究 ....................................................................................... 111 6.2 冻融条件下岩质边坡稳定性评价方法 ......................................................................................... 112 6.2.1 基于极限平衡法的冻岩边坡稳定性评价 .......................................................................... 112 6.2.2 基于屈服接近度的冻岩边坡稳定性评价 .......................................................................... 114 6.2.3 面向边坡设计寿命的稳定性评价与设计 .......................................................................... 115 6.3 冻融条件下岩质边坡稳定性影响因素及防护措施 ..................................................................... 116 6.3.1 冻融条件下冻岩边坡破坏模式 .......................................................................................... 116 6.3.2 冻融条件下冻岩边坡稳定性影响因素分析 ...................................................................... 118 6.3.3 面向实际工程应用的冻岩边坡稳定性防护措施研究 ...................................................... 126 6.4 露天煤矿冻岩边坡稳定性分析 ...................................................................................................... 128 6.4.1 露天煤矿边坡计算模型 ...................................................................................................... 128 6.4.2 冻融循环条件下边坡稳定性分析 ...................................................................................... 129 6.5 本章小结 ......................................................................................................................................... 134 7 结论与研究展望 ........................................................................................... 135 7.1 主要成果与结论 ............................................................................................................................. 135 7.1.1 多年冻土区边坡岩体的赋存特征及破坏模式 .................................................................. 135 7.1.2 冻融环境中岩石温度平衡规律与多场耦合机理 .............................................................. 135 7.1.3 岩石冻融损伤规律与模型 .................................................................................................. 136 7.1.4 岩体冻融损伤强度准则 ...................................................................................................... 137 7.1.5 冻融环境中露天矿冻岩边坡稳定性分析与评价方法 ...................................................... 137 7.2 研究展望与未来工作方向 ............................................................................................................. 138 致 谢 ................................................................................................................. 141 参考文献 ............................................................................................................... 143 在校期间承担的科研项目及获得的科技成果 ................................................. 153 万方数据 西安理工大学博士学位论文 IV 万方数据 1 绪论 1 1 绪论绪论 1.1 研究背景研究背景 1.1.1 世界及我国煤炭资源开发状况世界及我国煤炭资源开发状况 煤炭是一种常规的化石能源， 可用作工业和民用燃料及工业原料， 是自十八世纪第一 次工业革命以来人类社会的主要能源之一。我国是一个“富煤、缺油、少气”的国家，是世 界上煤炭资源储量最丰富的国家之一（图 1-1） ，煤炭资源分布广且种类齐全、煤质优良 （图 1-2） ，为我国的现代化工业快速发展提供了非常重要的基础条件。 图 1-1 世界煤炭资源储量排名前十国家分布图 Fig.1-1 The top ten countries distribution of world coal resources reserves 图 1-2 中国煤类分布图 Fig.1-2 Distribution of different coal types in China 万方数据 西安理工大学博士学位论文 2 但我国人口数量巨大，煤炭资源人均占比非常低，且随着经济的快速发展，工业和民 用对煤炭资源的消费逐年升高（图 1-3） ，虽然近年呈现下降