深埋煤岩体注浆加固效应与控制参数研究

发布时间：2018-03-17 15:22

本文选题：注浆材料　切入点：煤岩体　出处：《中国矿业大学》2015年硕士论文　论文类型：学位论文

【摘要】：深埋煤岩体在较高的地应力作用和地质活动的影响下自身存在大量的裂隙与节理、割理,在巷道掘进及工作面回采过程中,应力的重分布及回采动压会加剧煤岩体的变形破坏,影响巷道的稳定及工作面的安全回采。注浆加固是岩土工程中常用的加固技术手段,可以有效提高加固对象的物理力学参数,提高岩土体的自承载力。本文以晋煤集团赵庄煤业为背景,针对破碎及裂隙煤岩体的注浆加固问题,通过试验研究、理论分析、数值模拟和现场工程试验等方法对煤岩体的注浆材料性能、加固效果、注浆参数影响因素、渗透与劈裂注浆共同作用机制等问题进行了研究,主要得出以下几点成果:(1)通过室内试验对普通水泥、粉煤灰水泥和超细水泥的流变性、稳定性和凝结硬化性能进行了研究。获得了各型水泥在不同水灰比及不同时间下的流变性、结石率和2 h析水率;获得了浆液结石体的全应力-应变曲线、弹性模量、强度值;根据超细水泥强度拟合曲线获得其3 d、7 d和28 d养护龄期下的强度变化经验公式;总结了结石体试件的破坏形式并分析了成因。(2)通过对煤样和泥岩试样进行基本物理力学试验,获得了煤和泥岩的单轴抗压强度、残余强度、抗拉强度、内聚力和内摩擦角等值。基于浆液材料试验和物理力学试验,对破碎和裂隙煤岩体进行了注浆加固试验,获得了不同破碎程度和浆液强度条件下各注浆加固体的应力应变曲线,并对其强度、弹性模量、变形规律和破坏模式等进行了分析研究,得到了浆液强度和煤岩体破碎程度对注浆加固体的影响规律、煤岩体注浆的合理浆液强度指标,分析研究了浆液结石体强度不同时其加固体的应力应变曲线形式及变形破坏规律。(3)基于牛顿流体运动规律对单裂隙中浆液的扩散规律与控制参数进行了研究;基于弹性力学理论计算了使注浆孔孔壁在浆液压力和地应力作用下发生劈裂破坏的注浆压力值;基于损伤断裂力学理论分析计算了使裂隙发生扩展的浆液压力值及裂隙扩展长度。采用Abaqus分别计算了巷道埋深、水平构造应力场、巷道尺寸等因素对巷道与工作面劈裂注浆所需注浆压力的影响规律,并根据计算结果分析了注浆孔在无注浆压力下的自动开裂范围;分析了不同条件下围岩劈裂与扩展所需注浆压力的关系。(4)针对赵庄矿回采工作面切眼易出现煤帮片帮和顶板冒落以及辅助巷道的变形破坏问题,利用Abaqus对其工作面与巷道注浆合理控制参数进行了计算,提出了巷道与工作面注浆加固的技术方案与建议。
[Abstract]:Under the influence of high ground stress and geological activity, there are a large number of fractures and joints in deep buried coal and rock mass. In the process of roadway excavation and face mining, the stress redistribution and mining dynamic pressure will aggravate the deformation and destruction of coal and rock mass. The stability of roadway and the safety of mining face are affected. Grouting reinforcement is a commonly used reinforcement technique in geotechnical engineering, which can effectively improve the physical and mechanical parameters of the strengthened object. Taking Zhaozhuang Coal Industry of Jin Coal Group as the background, aiming at the problem of grouting reinforcement of broken and fractured coal and rock mass, this paper makes theoretical analysis through experimental study. Numerical simulation and field engineering tests have been carried out to study the performance of grouting materials, reinforcement effect, influencing factors of grouting parameters, and the interaction mechanism of permeation and split grouting of coal and rock mass. The main results are as follows: (1) the rheological properties of ordinary cement, fly ash cement and ultrafine cement are tested in laboratory. The stability and setting and hardening properties of cement were studied. The rheology, stone rate and 2 h water evolution rate of different cement types under different water / cement ratio and different time were obtained, and the total stress-strain curve, elastic modulus and strength value of slurry stone were obtained. According to the fitting curve of superfine cement strength, the empirical formula of strength change was obtained under the curing age of 3 days and 28 days, and the failure form of stone specimen was summarized, and the origin of stone sample was analyzed. The basic physical and mechanical tests were carried out on coal sample and mudstone sample. The uniaxial compressive strength, residual strength, tensile strength, cohesion force and angle of internal friction of coal and mudstone are obtained. The stress-strain curves of different grouting and solid were obtained under different crushing degree and slurry strength, and the strength, elastic modulus, deformation law and failure mode were analyzed and studied. The influence law of slurry strength and coal rock mass fragmentation on grouting and solid is obtained, and the reasonable grouting strength index of coal and rock mass grouting is obtained. The stress-strain curve and deformation and failure law of slurry stone with different strength are analyzed and studied. Based on Newtonian fluid motion law, the diffusion law and control parameters of slurry in a single fissure are studied. Based on the elastic theory, the grouting pressure value of the grouting hole wall under the action of grouting pressure and in-situ stress is calculated. Based on the theory of damage and fracture mechanics, the pressure value of slurry and the length of crack propagation are calculated. The buried depth and horizontal tectonic stress field of roadway are calculated by Abaqus, respectively. The influence of roadway size on grouting pressure required by splitting grouting in roadway and working face is studied, and the automatic cracking range of grouting hole under no grouting pressure is analyzed according to the calculation results. This paper analyzes the relationship between surrounding rock splitting and grouting pressure required for expansion under different conditions. (4) aiming at the problems of coal side and roof caving and auxiliary roadway deformation and destruction in Zhaozhuang mining face, the cutting hole is easy to occur. The reasonable control parameters of grouting in working face and roadway were calculated by Abaqus, and the technical scheme and suggestion of grouting reinforcement in roadway and working face were put forward.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD353

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