应力作用下破碎岩体变形与水沙渗流特性试验研究.pdf

博士学位论文 应力作用下破碎岩体变形与水沙 渗流特性试验研究 Study on the Deation of Broken Rocks Under Stress and Water-Sediment Seepage 作 者陈家瑞 导 师浦 海 教授 中国矿业大学 二〇一六年十二月 万方数据 中图分类号 TD315 学校代码 10290 UDC 密 级 公开 国家重点基础研究发展计划项目973 计划2015CB251601 国家优秀青年科学基金（51322401） 国家创新研究群体科学基金（51421003） 中国矿业大学 博士学位论文 应力作用下破碎岩体变形与水沙 渗流特性试验研究 Study on the Deation of Broken Rocks Under Stress and Water-Sediment Seepage 作 者 陈家瑞 导 师 浦 海 教授 申请学位 工学博士 培养单位 深部岩土力学与地下 工程国家重点实验室 学科专业 工程力学 研究方向 采动岩体力学与工程 答辩委员会主席 朱珍德 教授 评 阅 人 盲审 二○一六年十二月 万方数据 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 万方数据 论文审阅认定书论文审阅认定书 研究生 陈家瑞 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 万方数据 致谢致谢 论文是在导师浦海教授的悉心指导下完成的， 在论文选题上给予了高瞻远瞩 的指导，在实验研究上，给予了资金上的大力支持和技术上的帮助；在论文框架 的构建以及最后的文理疏通、审阅定稿等每一步工作中，导师也都倾注了大量的 心血和智慧。求学几年中，导师在学习、生活、及工作上给予了学生巨大的帮助 和支持，导师独特的人格魅力、敏锐的学术眼光、每次的谆谆教诲、都令学生终 身难忘。在此，谨向我的导师浦海教授致以衷心的感谢 感谢陈占清教授、茅献彪教授、王连国教授、白海波教授、马占国教授等在 学术及论文写作方面所给予的指导。 感谢徐平老师在理论建模分析、试验方案设计等方面给予的指导和帮助；感 谢李明博士的支持。 感谢同窗好友曹丽丽博士、仇培涛博士、肖成硕士、孟凡非硕士、倪宏阳硕 士、张继华博士、黄耀光博士、刘桂宏博士、陆敬锋硕士、沙子恒博士、柳森昊 硕士、曹正正博士、彭刚老师、邱艳勇硕士、蒋邦友博士、张文涛硕士、张璞博 士、李兵博士、张立强博士、孙小康博士等的帮助。 衷心感谢学校领导和老师们同学们多年来在学习和生活上给予的关心、 鼓励 和帮助。 感谢我的家人，是你们的奉献支撑了我的求学。 感谢所引参考文献中成果的作者， 他们卓越的研究工作为本文奠定了良好的 基础。 感谢各位专家和学者在百忙之中评审论文，衷心希望得到您的指导和帮助。 万方数据 I 摘摘 要要 采动岩体水沙渗流特性研究是关系煤矿安全的一项重要课题。 岩体由于采动 引起结构破坏，产生的破碎岩体往往处于围压之下。本文自行研制了一套加载设 备相配套的渗透试验设备对应力作用下破碎岩体变形与水沙渗流特性进行研究， 取得了如下创新性成果 （1）为了研究应力作用下破碎岩体变形与水沙渗流特性，自行研制了一套 与加载设备相匹配的渗流试验设备。使破碎岩体能够在应力下发生流变，研究流 变后的破碎岩体的水沙渗流特性。该渗流设备能模拟围压下破碎岩体的流变变 形；破碎岩体与沙粒分层，沙粒受水流搅动后形成水沙混合物流入破碎岩体的情 况。可为同类试验以及相关后续的扩展研究提供参考方法。 （2）利用自行研制的应力作用下破碎岩体水沙渗流试验系统，研究了不同 应力水平、不同粒径级配对破碎岩体流变特性与水沙渗流特性的影响。破碎岩体 压实流变过程中，流变模型的弹模、粘度等参数是不停的随时间变化的。根据破 碎岩体流变试验结果，基于分数阶微积分理论与三参量流变模型，引入分数阶 Abel 粘壶替代牛顿粘壶，获得了一个新的分数阶流变模型，并推导了岩石在恒 应力条件下的三维蠕变本构方程；分析了破碎岩体流变对水沙渗流特性的影响。 （3）破碎岩体水沙渗流过程中，一部分沙粒流入破碎岩体后被截留，占据 了部分空隙，改变了破碎岩体的孔隙率。拟合了不同粒径级配的破碎岩体在两种 渗流组合的情况下，初始孔隙率与渗透率的关系式；拟合了不同粒径级配的破碎 岩体的溃沙、滤沙能力与破碎岩体初始孔隙率的关系曲线。对破碎岩体进行应力 加载（流变变形）与位移加载两种方式使破碎岩体发生压缩变形以研究不同的加 载方式对破碎岩体水沙渗流特性的影响。 （4）当破碎岩体中发生水沙渗流情况时，在一定情况下，沙粒不能够完全 通过破碎岩体，破碎岩体对沙粒的过滤作用进而导致破碎岩体骨架属性变化，破 碎岩体的对沙粒的过滤能力是对其渗流特性影响的一项重要因素。 根据试验结果 提出了考虑渗流长度的破碎岩体筛层模型， 并对破碎岩体等效厚度与破碎岩体初 始孔隙率的关系进行了研究，给出了建议的计算公式，基于颗粒离散元软件 （PFC）进行了破碎岩体水沙渗流数值模拟。可为破碎岩体水沙渗流灾害的预测 提供参考。 该论文有图 58 幅，表 15 个，参考文献 237 篇。 关键词关键词破碎岩体；突水溃沙；分数阶微积分；流变模型 万方数据 II Abstract Mining rock mass water-sand seepage characteristics study is an important topic pertinent to coal mine safety. The structure of rock mass may be destroyed due to mining activities and the broken rock masses will often bear confining pressure. This article is to introduce a pressurized permeability test device compatible with the loading equipment and designed to study the deation and water-sand seepage characteristics of broken rock mass under the action of stress, and to describe the following innovative achievements so far made 1 In order to study the broken rock deation and water-sand seepage characteristics under the action of stress, a pressurized permeability test device compatible with the loading equipment has been developed independently. The device is able to cause rheological deation of broken rock mass so as to study the water-sand seepage characteristics of the deed broken rock mass. The pressurized permeability test device is able to mimic the process of rheological deation of the broken rock mass under confining pressure where the broken rock mass and sand come separate in different layers and the sand, stirred by water flow and mixed with water, crushes into the broken rock mass. This test is able to provide reference for similar tests and future extended studies. 2 The effects of different stress levels and size grading on rheological properties and water-sand seepage characteristics of broken rock mass have been studied using the self-developed water-sand seepage testing system for broken rock mass under the action of stress. In the course of compaction and rheological deation, broken rock mass undergoes constant changes in such parameters as elasticity modulus and viscosity coefficient. According to the broken rock mass rheological test result and based on fractional calculus theory and the broad sense of Kelvin rheological model, fractional Abel dashpot has been introduced to substitute Newton dashpot, create a new fractional rheological model and deduce the three-dimensional creep constitutive equation of rock under the action of constant stress; and the effect of seepage on the creep properties of rock has been analyzed. 3 In the course of water-sand seepage of broken rock mass, some of the sand is held back after flowing into the broken rock mass, occupies part of the space and changes the porosity of the broken rock mass. This article also works out the relationship between original porosity and seepage coefficient for seepage of broken 万方数据 III rock mass with different size grading and in different fluid; and the curve relation between the sand inrush and filtering capacity and original porosity of broken rock mass with different size grading. Apply stress loading rheological deation and direct compressive loading to broken rock mass and cause it to suffer compressive deation so as to study the effects of different loading s on the water-sand seepage characteristics of broken rock mass. 4 If water-sand seepage occurs within broken rock mass, not all sand can go through the broken rock mass in certain cases. The sand filtering function of the broken rock mass will result in change in the skeleton property of the broken rock mass, making such function an important factor influencing the seepage properties of the broken rock mass. Based on the test result, the screen layer model of broken rock mass taking seepage process into consideration has been brought forth, the relationship between the equivalent thickness and original porosity studied, and the suggested computational ula given; numerical simulation of water-sand seepage of broken rock mass has been carried out based on particle flow code PFC. This may provide reference for the prediction of water-sand seepage disaster of broken rock mass. This paper contains 58 figures, 15 tables and 237 references Keywords fractured rock mass; water-sediment seepage; fractional calculus; rheological model 万方数据 IV Extended Abstract Rocks under mining may undergo change in their stress condition due to mining Excavation activities, thus causing the fracture and movement of rock structure. Mining damage to the rock mass, when spreading to the water- and sand-bearing stratum, often leads to water and sand inrush accident. Broken rock mass generated in mining work is often under confining pressure. In order to study the deation and water-sand seepage characteristics of broken rock mass under the action of stress, a pressurized permeability test device compatible with the loading equipment, has been developed independently and equipped with sensor, paperless recorder and other real-time data collection and analysis system to a complete set of broken rock mass deation and water-sand seepage characteristics testing system. Upon inspection, the test equipment lives up to the designed function. This article mainly studies the following 1 In order to study the deation and water-sand seepage characteristics of broken rock mass under the action of stress, a pressurized permeability test device compatible with the loading equipment, has been developed independently and equipped with sensor, paperless recorder and other real-time data collection and analysis system to a complete set of broken rock mass deation and water-sand seepage characteristics testing system. The device is able to cause rheological deation of broken rock mass so as to study the water-sand seepage characteristics of the deed broken rock mass. The device has preliminarily revealed the water-sand seepage phenomenon under the action of stress, providing an effective means of predicting the water and sand inrush within the broken rock mass under confining pressure. The whole design of the deation and water-sand seepage characteristics testing system for broken rock mass under the action of stress is reasonable and complete, and its components are compact and fitted with each other. The pressurized permeability test device is able to mimic the process of rheological deation of the broken rock mass under confining pressure where the broken rock mass and sand come separate in different layers and the sand, stirred by water flow and mixed with water, crushes into the broken rock mass. This device is able to record the test data in real time and provide reference for similar tests and future extended studies. 2 The size grading of broken rock mass has a certain impact on its deation 万方数据 V characteristics. Under the action of the same axial stress, the sample broken rock mass of different size grading may generate different maximum strain value when deed under pressure. Under the action of the same axial stress, the larger the size grading, the bigger the strain value of broken rock mass, when deed under pressure. When the axial stress is at a low level 1.53 MPa, the curve of maximum stress value of broken rock mass is on apparent decelerated growth. With the increase of axial stress, the decelerating trend of growth in the curve becomes gradually weak. When the axial stress increases to 15.28 MPa, the curve relation between the maximum stress and size grading of broken rock mass is almost a linear one and the effect of size grading on the maximum deation of broken rock mass under axial compression can almost be ignored. The size grading, original porosity and axial loading all have impact on seepage characteristics of broken rock mass. The seepage of water and sand within broken rock mass may cause phenomenon like sand inrush and filtering. 3 According to the broken rock mass rheological test result and based on fractional calculus theory and the broad sense of Kelvin rheological model, fractional Abel dashpot has been introduced to substitute Newton dashpot, create a new fractional rheological model and deduce the three-dimensional creep constitutive equation of rock under the action of constant stress; and the effect of seepage on the creep properties of rock has been analyzed. The rheological parameter of the new model has been studied based on the theory of rheological test graded loading and the subsequent new fractional rheological model. According to the seepage mechanics theory and based on the new fractional rheological model, fractional rheological-seepage coupling model has been set up to pave the way for study of water-sand seepage of broken rock mass. Based on the fractional rheological-seepage coupling model, embed the new model into Comsol using Matlab as the bridge and verify the accuracy of new fractional rheological deation through simulation of the test result. 4 Apply stress loading rheological deation and direct compressive loading to broken rock mass and cause it to suffer compressive deation so as to study the effects of different loading s on the water-sand seepage characteristics of broken rock mass. When the seepage fluid is water, the two loading s have no apparent impact on the seepage characteristics of broken rock mass; when the seepage fluid is water-sand mix, the skeleton structure of broken rock mass after it filters, impedes or otherwise acts on the sand particles, thus affecting the 万方数据 VI permeability of the broken rock mass. Study shows that broken rock mass under the action of creep, its sand filtering capacity will be increased and sand inrush capacity weakened, which may to some extent mitigate the water and inrush disaster. 5 In seepage test, seepage characteristics are often regarded as the inherent characteristics of seepage media. Upon seepage behavior study, fluid pressure is often converted into fluid pressure gradient rather than taking the seepage length of fluid into direct consideration. However, the study described above finds that if water-sand seepage occurs within broken rock mass, not all sand can go through the broken rock mass in certain cases; the sand filtering function of the broken rock mass will result in change in the skeleton property of the broken rock mass, making such function an important factor influencing the seepage properties of the broken rock mass. Based on the test result, the screen layer model of broken rock mass has been brought forth, the relationship between the equivalent thickness and original porosity studied, and the suggested computational ula given, providing reference for the prediction of water-sand seepage disaster of broken rock mass. 6 Study of water-sand seepage behavior of broken rock mass based on Particle Flow Code. The study finds that the fluid pressure in broken rock mass decreases in the direction of seepage. But due to the influence of particle size and arrangement, the water pressure on the horizontal section of broken rock mass varies from point to point and hydraulic gradient takes on a three-dimensional status; the water velocity within broken rock mass is not uni and varies significantly due to the influence of particle size and arrangement; study on distribution of sand particles within broken rock mass shows that the sand particles filtered within broken rock mass decreases in the direction of seepage and a lot of sand particles are concentrated on the top part of broken rock mass. Meanwhile, the correctness of screen layer model has been verified through delamination of the model and weighing of sand particles in each layer. Keywords fractured rock mass; water-sediment seepage; fractional calculus; rheological model 万方数据 VII 目目 录录 摘摘 要要............................................................................................................................ I 目目 录录........................................................................................................................ VII 图清单图清单......................................................................................................................... XI