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破碎煤岩体化学注浆加固材料研制及渗透扩散特性研究
Material Development and Research of Osmosis and Diffusion on Chemical Grouting for Extraordinary Cracked Coal and Rockmass
【作者】 冯志强;
【导师】 康红普;
【作者基本信息】 煤炭科学研究总院 , 采矿工程, 2007, 博士
【摘要】 注浆是一种比较成熟的岩体加固技术,在煤矿井下采煤工作面和巷道的加固、巷道顶板涌水的封堵、坝体坝基防渗堵漏、基坑加固、海底隧道、建筑物抬升或纠偏、边坡和地基加固等工程中都得到了广泛的应用。与此同时,各种注浆新材料、新工艺和新设备层出不穷,极大地促进了注浆技术的发展。与此不对称的是注浆理论却进展缓慢,研究水平相对落后。主要因为注浆是隐蔽性工程,而且是复杂的系统工程,受制约的影响因素很多,主要有:浆液性质、注浆设计、注浆工艺及被注煤岩体地质力学性质等,甚至还得考虑环境保护等要求。本文论述了注浆的发展过程,注浆材料以及注浆的分类,以及详细总结和分析了渗透注浆的基础理论,主要从浆液的流变性,被注介质与浆液的作用关系,注浆压力的选取,浆液的扩散规律等方面做了比较深入的研究工作,并取得了一些成果。(1)开发了兼有堵水和加固作用的聚氨酯注浆材料。该注浆材料以水为固化剂,消除了因密封件磨损等设备原因和管路堵塞等其他原因引起的双组份比例不匹配,造成的浆液固化质量下降。可以对矿井大范围淋水条件下破碎煤岩体进行有效封堵水与加固。(2)开发了低粘度强渗透性低毒的脲醛树脂注浆材料。该材料在环境温度15℃~25℃时的粘度为60Cp~30Cp,固化速度可以根据固化剂的用量随施工条件调节,抗压强度达到5MPa以上。适用于煤矿采掘过程中,结构软弱、松散,强度极低的煤岩体加固,以保证矿井正常的生产,消除矿井的安全隐患。(3)自行设计了恒压三维渗透注浆模拟试验及装置,通过试验得出了渗透系数与围压及浆液的粘度近似成反比。(4)从岩体中裂隙分布、渗流水力学特征与化学注浆堵水机理出发,详细分析了影响渗透水裂隙的形成及分类,破碎煤岩体注浆堵水作用机理。(5)在基于浆液粘度的时变性规律,并考虑了裂隙倾角和方位角、地下静水压力等诸多影响因素,建立了牛顿流体注浆扩散模型,发展了注浆扩散理论。随着注浆时间的延长,注浆扩散半径不断增大。注浆半径在后期的增长明显小于注浆前期扩散半径的增长。注浆前锋面上的压力梯度逐渐降低,裂隙通道上各点的压力急剧减小(但不呈线性关系),浆液流速和注浆流量逐渐减小,注浆扩散半径存在极限值。(6)浆液流变性、裂隙产状和注浆工艺参数对扩散半径的影响很大。浆液初始粘度越大,或者粘度时变性越大,扩散半径越小;扩散半径随力学开度的增大而急剧增长,随注浆压力的增大也呈增大趋势,随地下水静压力的增大而减小。(7)通过工程实例进行对比分析,证明本文建立的注浆扩散理论反映了注浆扩散规律,试验结果接近工程实际。本文注浆扩散模型考虑了较多的影响因素,对有关假设和前提作了深入的试验研究和对比分析后得到了定性规律和定量结论,计算中所需的地质参数和浆液性能也可准确测试出来,因而本文建立的扩散模型有一定的实用价值。
【Abstract】 Grouting is widely applied to reinforce working face and roadways, plugging water of roof in mine, preventing leakage and reinforcing surrounding rock of dam foundation, rising and correcting building and so on. At the same time, grouting technology is greatly developed by multifarious new grouting materials, new technology and new equipment. By contraries, study on grouting theory develops slowly. The main reason is that grouting is a complicated and systematical technology and affected by many factors which are material character, joint character, grouting technics, climate, design environment and so on.In this paper, development of grouting, grouting material and classification of grouting are discussed. Basic theories associated with permeability of grouting are analyzed and summarized in detail. Some new perspectives about rheology of material, relation effecting grouted medium, grouting stress, etc are introduced. Preliminary study has been done. Some results are discussed as follows:1.New polyurethane grouting material with effects of waterproofing and rockmass reinforcing has been developed. This material avoids scale unmatching caused by abrasion of sealed components and congestion of pipelines, and can effectively reinforce and close over availably cracked coal and rockmass on condition that large-scale pours water in mine.2.New urea-formaldehyde resin grouting material has been developed which has low-lying viscosity and virulence and strong penetrability. The viscosity of the material is 60Cp~30Cp when condition temperature is 15℃~25℃, solidified speed may be adjusted accordingly as solidified dose and the uniaxial compressional intensity can exceed 5MPa. Roof falling due to dislocation of weak incompact coal and rockmass can be solved rockmass through grouting the material. The potential safety problems are removed and the mine can be normally extracted and drilled.3.A three-dimensional, stress invariable penetrating experimentation and device has been independently designed. An inverse proportional relation between penetrative coefficient and surrounding stress and viscosity of the material was obtained through the test.4.Formation and distribution of flaw of affecting seepage flow are detailedly analyzed depart from distribution of flaw in rockmass, character of seepage flow and mechanism of chemical grouting.5.Newton liquid grouting diffusing model is established and grouting diffusing theory is developed based on time-variance of serum’s viscosity as well as other factors such as obliquity and azimuth of crack and underground water stress. The outstretched radius of serum increases constantly along with grouting time, and the increase ratio of the outstretched radius of serum is faster in early period than in late period.It is concluded that stress grads of frontal surface gradually and stress in cranny channels reduce, and velocity of serum flow and flux of serum gradually decrease. There is a extremum in grouting outstretched radius. 6.The radius of serous diffusion is bigger according to initial viscosity of fluid , mechanic width of flaw and pressure of grouting, because breed of flaw and grouting craft affect the radius of serous diffusion.7.It is proved through case studies that the grouting outstretched theory reflects serous fluid outstretched rules and the results are consistent with the practical application. Based on comprehensive study and comparatively analyzing on the hypothesis and presupposition involved, the qualitative rule and quantitative conclusion are achieved. The necessary geological parameters and serosity capability can be measured through the grouting outstretched model. The model discussed in this paper has some practical values.
【Key words】 Cracked coal and rockmass; chemical grouting; polyurethane; urea-formaldehyde resin; penetrative grouting; serosity diffusing;