深埋破碎岩体劈裂渗透及卸压诱导注浆扩散机制

发布时间：2019-02-13 03:37

【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)通过渗透注浆中浆液沿平面裂隙作圆周扩散和沿平面裂隙单向扩散两种形式进行了分析研究,获得了渗透注浆中注浆压力与扩散范围的关系。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,并由分析可知对劈裂注浆所需压力影响最大因素是与注浆孔垂直平面上的σ1与σ3比值,比值越大,越容易实现注浆孔孔壁劈裂;基于损伤断裂力学理论分析计算了使裂隙发生扩展的压力值及扩展长度。(2)为了对破碎煤体进行注浆,在参考了相关资料的基础上设计了一套注浆装置。并对注浆后的注浆加固体进行了单轴和三轴压缩试验,获得了峰值强度与围压、峰值强度与孔隙率、峰值强度与注浆压力、残余强度与围压、残余强度与孔隙率、残余强度与注浆压力、峰值应变与围压、峰值应变与孔隙率及峰值应变与注浆压力关系式,并对其进行了分析讨论,得到了孔隙率及注浆压力对注浆效果的影响规律。注浆加固体的强度随着被注材料和注浆材料强度的增长而增长,但是注浆加固体的峰值强度主要是由注浆材料的强度决定的。(3)利用软件COMSOL分别建立二维和三维的模型,通过对不同孔隙率、不同注浆压力及不同注浆材料进行注浆模拟模拟。根据模型中选取点的孔隙水压力变化情况分析了实际注浆过程中不同位置浆液扩散情况,并得到了孔隙率、注浆压力及浆液粘度对注浆效果的影响程度及规律。(4)结合工作面的工程地质条件与回采情况,提出综采工作面超深孔顺槽注浆加固技术方案与参数,根据方案对工作面进行了注浆并在后期进行了跟踪记录。通过对煤壁片帮、顶板掉落、巷道变形、瑞米用量及工作面的推进速度进行了分析,结果表明,设计方案的注浆效果达到了预期的目标,对增强工作面的稳定性有着非常重要的作用。
[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. It affects the stability of roadway and the safety of mining face. Grouting reinforcement is a commonly used reinforcement technique in geotechnical engineering, which can effectively improve the physical and mechanical parameters of the reinforcement object and the self-bearing capacity of the rock and soil mass. In this paper, based on Zhaozhuang Coal Industry of Jin Coal Group, aiming at the problem of grouting reinforcement of broken and fractured coal and rock mass, through experimental research, theoretical analysis, numerical simulation and field engineering test, the grouting material performance and reinforcement effect of coal and rock mass are studied. The influence factors of grouting parameters, the interaction mechanism of permeation and split grouting were studied. The main results are as follows: (1) the relationship between grouting pressure and diffusion range in permeable grouting is obtained by analyzing and studying the two forms of slurry diffusion along the plane fissure and unidirectional diffusion along the plane fissure. 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. The ratio of 蟽 _ 1 to 蟽 _ 3 on the vertical plane of grouting hole is the biggest influence factor on the pressure required for splitting grouting, and the bigger the ratio is, the easier it is to realize the splitting of grouting hole wall. Based on the theory of damage fracture mechanics, the pressure and length of crack propagation are calculated and analyzed. (2) in order to grouting the broken coal body, a grouting device is designed on the basis of referring to the relevant data. The uniaxial and triaxial compression tests of grouting and solid were carried out, and the peak strength and confining pressure, peak strength and porosity, peak strength and grouting pressure, residual strength and confining pressure, residual strength and porosity were obtained. The relationship between residual strength and grouting pressure, peak strain and confining pressure, peak strain and porosity, and peak strain and grouting pressure were analyzed and discussed, and the influence of porosity and grouting pressure on grouting effect was obtained. The strength of grouting plus solid increases with the increase of the strength of the grouting material and the grouting material, but the peak strength of the grouting and solid is mainly determined by the strength of the grouting material. (3) the 2D and 3D models are established by using the software COMSOL, respectively. Different porosity, different grouting pressure and different grouting materials were simulated. According to the variation of pore water pressure at selected points in the model, the diffusivity of slurry at different positions in the actual grouting process is analyzed, and the porosity is obtained. The influence degree and law of grouting pressure and slurry viscosity on grouting effect. (4) combined with the engineering geological conditions and mining conditions of the working face, the technical scheme and parameters of grouting reinforcement in ultra-deep hole and downstream groove of fully mechanized coal mining face are put forward. According to the scheme, grouting is carried out on the working face and the track record is carried out in the later stage. Through the analysis of coal wall cover, roof drop, roadway deformation, Remy dosage and working face speed, the result shows that the grouting effect of the design scheme has reached the expected goal. It plays a very important role in enhancing the stability of working face.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD265.4

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