煤矸石风化强度特性及稳定性研究.pdf

煤矸石风化强度特性及稳定性研究 重庆大学硕士学位论文 （学术学位） 学生姓名贺文俊 指导教师刘东燕 教 授 专 业土木工程 学科门类工 学 重庆大学土木工程学院 二 O 一六年五月 万方数据 万方数据 Coal gangue weathering strength characteristics and stability study A Thesis ted to Chongqing University in Partial Fulfillment of the Requirement for the Master’s Degree of Engineering By He Wenjun Supervised by Prof. Liu Dongyan Specialty Civil Engineering College of Civil Engineering of Chongqing University, Chongqing, China May, 2016 万方数据 万方数据 中文摘要 I 摘 要 煤矸石是煤炭开采及洗选过程中产生的固体废弃物，是我国目前年排弃量和 积存量第一的工业废渣。矸石散体粒径分布范围较大，数十厘米的石块到小于 0.1 毫米的细小颗粒都是其散体成分。其物质成分硬度相差甚远，从软岩到硬岩石均 包含在内，还包含了部分残留煤，另外还有大量的有机质以及易挥发的可燃硫成 分等，物理化学性质及力学特征明显不同于一般粘土、砂砾土及其它散体材料。 煤矸石排弃后堆积成矸石山，矸石山露天堆放不仅会侵占农田，对水体、土 壤以及大气均会产生严重污染，还可能产生自燃、爆炸等灾害。其风化后，煤矸 石力学性质会产生变化，会产生结构损害、边坡稳定等环境岩土效应，不仅危及 井筒运营的安全性，还对矿区内人员的生命财产安全产生严重影响。因此，我国 急需解决矸石山所造成的环境影响及稳定性问题。 本文针对重庆区域具有代表性的矸石山，以重庆某煤矿矸石山为研究背景， 在现场试验及室内粗粒土大型三轴试验的基础上，从矸石风化特性出发，分析矸 石风化强度特性，采用极限分析上限法及不平衡推力法分析矸石山的稳定性，并 对矸石山的稳定性进行数值模拟分析，取得了如下成果 ①通过筛分试验，测定重庆某煤矿矸石山新排矸石与风化矸石级配，并将筛 分后的新排矸石配成与风化矸石相同的级配，以天然含水率与饱和含水率及不同 围压为控制条件，然后通过室内粗粒土大型三轴试验，研究比较两种煤矸石的力 学性质，对比分析了新排矸石及风化矸石三轴强度的力学性质。 ②运用不平衡推力法来推算重庆某煤矿矸石山的边坡稳定性；同时，针对矸 石山体内滑移失稳模式，建立极限分析上限法分析重庆某煤矿矸石山的稳定性。 ③在分析煤矸石力学性质的基础上，采取对应的摩尔-库伦本构关系以及破坏 准则，针对重庆某煤矿矸石山稳定性进行 FLAC 数值模拟，讨论重庆该煤矿矸矸 石山的稳定性及其影响因素。 关键词关键词大型三轴试验，风化矸石，新排矸石，矸石山稳定性 万方数据 重庆大学硕士学位论文 II 万方数据 英文摘要 III ABSTRACT Coal gangue is one of solid waste produced in the process of coal mining and washing which is the largest annual emissions and accumulated stock of industrial waste residues in the present china. The composition of coal gangue is mixture of soft or hard rock and a certain amount of residual coal which is rich in organic components and volatile combustible sulfur content. The particles from tens of centimeters stone to the tiny particles under 0.1 mm, particle size distribution, physical and chemical properties and mechanical characteristics significantly different from that of general clay, gravel soil, and other medium materials. If coal gangue piled up in an open-air way, it could occupy farmland, produce environmental geotechnical effect such as pollution water, soil and atmosphere and structure erosion, spontaneous combustion, explosion. After it’s weathering, coal gangue’s mechanical properties can be changed, it could produce environmental geotechnical effect such as structural damage, the slope stability. All these effects constitute a threaten for wellbore safety operation, the mining area of peoples life, and property safety. Therefore, the environmental and geotechnical problems caused by coal gangue are urgently needed to solve in our country. This paper, aim at typical coal gangue mountain in chongqing area, and one of the coal gangue piles in Chongqing as the research background, combining with the reconnaissance, field test and indoor large-scale triaxle test, coarse grained soil from the weathering of coal gangue, the analysis of the mechanism of the weathering coal gangue piles and build the maximum limit analysis and imbalance thrust for analyzing the stability of coal gangue. Moreover, the internal failure mechanism of coal gangue piles are numerical simulation analysis, obtained the following results ①Through screening, gradation of coal seams of the new south ore old waste rock and coal gangue waste rock will be determined, then, grading the new after screening waste rock as the same as the weathering coal gangue. Taking natural moisture content and saturation moisture content as the control conditions, through the indoor large-scale triaxle test, compared two kinds of mechanical properties of coal gangue getting studied, contrast analyze the diffenrence of new coal gangue and weathering coal gangue in triaxial strength and mechanical properties. 万方数据 重庆大学硕士学位论文 IV ②The imbalance thrust is used in this paper to calculate the slope stability of the coal gangue in Chongqinag. At the same time, according to the internal sliding instability mode of coal gangue piles, analysis of the limit analysis upper bound is established and applied to make sure the stability of coal gangue. ③ Based on the analysis of mechanical properties of coal gangue, the corresponding Mohr-coulomb constitutive relation can be adopted. Aiming at coal seams in chongqing coal mine gangue mountain, the stability of FLAC numerical simulation have being conduct, in order to master the stability of and influence factors of coal gangue piles in Chongqing. Keywords Large-scale triaxle test, Weathering coal gangue, New coal gangue, The stability of coal gangue piles 万方数据 目 录 V 目 录 中中文摘要文摘要 .......................................................................................................................................... I 英文摘要英文摘要 ....................................................................................................................................... III 图图 索索 引引 ..................................................................................................................................... VII 表表 索索 引引 ....................................................................................................................................... IX 主要符号主要符号 ....................................................................................................................................... XI 1 绪绪 论论 ...................................................................................................................................... 1 1.1 论文研究的目的和意义论文研究的目的和意义 ........................................................................................................... 1 1.2 国内外研究现状国内外研究现状 ....................................................................................................................... 2 1.2.1 煤矸石基本性质及危害 .................................................................................................... 2 1.2.2 矸石山稳定性理论分析研究 ............................................................................................ 5 1.2.3 矸石山稳定性数值模拟研究 ............................................................................................ 7 1.3 本文的主要研本文的主要研究内容究内容及思路及思路 ................................................................................................... 7 1.4 技术路线技术路线 ................................................................................................................................... 8 2 重庆某煤矿矸石山概况重庆某煤矿矸石山概况 ............................................................................................... 11 2.1 引言引言 ......................................................................................................................................... 11 2.2 重庆地区矸石山破坏类型重庆地区矸石山破坏类型 ..................................................................................................... 11 2.3 重庆某煤矿矸石山概况重庆某煤矿矸石山概况 ......................................................................................................... 13 2.3.1 重庆某煤矿矸石山区域地质水文气象 .......................................................................... 13 2.3.2 重庆某煤矿矸石山堆积特点 .......................................................................................... 14 2.3.3 重庆某煤矿矸石山周围环境 .......................................................................................... 15 2.4 本章小结本章小结 ................................................................................................................................. 16 3 重庆某煤矿矸石三轴强度试验重庆某煤矿矸石三轴强度试验 ............................................................................... 19 3.1 引言引言 ......................................................................................................................................... 19 3.2 煤矸石物理参数测定煤矸石物理参数测定 ............................................................................................................. 19 3.2.1 煤矸石现场试验 .............................................................................................................. 19 3.2.2 煤矸石室内试验 .............................................................................................................. 20 3.3 煤矸石力学参数测定煤矸石力学参数测定 ............................................................................................................. 22 3.3.1 粗粒土大型三轴试验 ...................................................................................................... 22 3.3.2 粗粒土大型三轴试验数据分析 ...................................................................................... 36 3.4 本章小结本章小结 ................................................................................................................................. 41 4 矸石山稳定性矸石山稳定性理论理论分析分析 ............................................................................................... 43 万方数据 重庆大学硕士学位论文 VI 4.1 引言引言 ......................................................................................................................................... 43 4.2 极限分析上限法基本理论极限分析上限法基本理论 ..................................................................................................... 43 4.2.1 塑性极限分析法上限定理 .............................................................................................. 43 4.2.2 矸石山稳定性塑性极限分析法上限解 .......................................................................... 45 4.3 不平衡推力法基本理论不平衡推力法基本理论 ......................................................................................................... 53 4.3.1 不平衡推力法理论原理 ................................................................................................... 53 4.3.2 矸石山安全系数求解 ....................................................................................................... 55 4.4 本章小结本章小结 ................................................................................................................................. 57 5 矸石山稳定性数值模拟矸石山稳定性数值模拟 .............................................................................................. 59 5.1 引言引言 ......................................................................................................................................... 59 5.2 FLAC 数值模拟软件简介及模型的确立数值模拟软件简介及模型的确立 .............................................................................. 59 5.2.1 FLAC 数值模拟软件简介 ................................................................................................ 59 5.2.2 强度准则的确定 .............................................................................................................. 59 5.2.3 计算流程的确定 .............................................................................................................. 60 5.3 矸石山稳定性数值分析矸石山稳定性数值分析 ......................................................................................................... 61 5.3.1 计算工况的选取 .............................................................................................................. 61 5.3.2 数值模拟结果分析 .......................................................................................................... 62 5.3.3 不同工况下的数值模拟结果分析 .................................................................................. 68 5.4 本章小结本章小结 ................................................................................................................................. 77 6 结论与展望结论与展望 ......................................................................................................................... 79 6.1 本文主要结论本文主要结论 ......................................................................................................................... 79 6.2 未来矸石山研究的展望未来矸石山研究的展望 ......................................................................................................... 80 致致 谢谢 ...................................................................................................................................... 81 参考文献参考文献 ...................................................................................................................................... 83 万方数据 图 索 引 VII 图 索 引 图 1.1 煤矿矸石山滑坡 .................................................................................................................... 1 图 1.2 技术路线图 ............................................................................................................................ 9 图 2.1 沿矸石山体内滑移 .............................................................................................................. 13 图 2.2 重庆某煤矿地理位置 .......................................................................................................... 14 图 2.3 煤矸石运输及倾倒 .............................................................................................................. 15 图 2.4 重庆某煤矿矸石山整体外观 .............................................................................................. 15 图 2.5 重庆某煤矿矸石山周围环境 .............................................................................................. 16 图 2.6 重庆某煤矿矸石山简图 ...................................................................................................... 16 图 3.1 煤矸石现场取样 .................................................................................................................. 20 图 3.2 煤矸石天然、饱水含水率测定 .......................................................................................... 21 图 3.3 煤矸石筛分 .......................................................................................................................... 21 图 3.4 YS303B 大型三轴试验机 ............................................................................................... 23 图 3.5 拌合试样 .............................................................................................................................. 27 图 3.6 绑扎乳胶管 .......................................................................................................................... 28 图 3.7 拆除套筒 .............................................................................................................................. 29 图 3.8 制作成功的试样 .................................................................................................................. 29 图 3.9 吊装外壳 .............................................................................................................................. 30 图 3.10 拆除乳胶膜 .......................................................................................................................... 31 图 3.11 风化矸石饱和试件在不同围压下的破坏形态 ................................................................... 32 图 3.12 风化矸石天然试件在不同围压下的破坏形态 .................................................................. 33 图 3.13 新排矸石饱和试件在不同围压下的破坏形态 .................................................................. 34 图 3.14 新排矸石天然试件在不同围压下的破坏形态 .................................................................. 35 图 3.15 煤矸石∆FS 曲线 ................................................................................................................ 37 图 3.16 煤矸石应力-应变曲线 ....................................