煤岩裂隙高位注浆浆液扩散规律  

Diffusion law of high-position grouting in coal and rock fracture

作　　者：戚绪尧[1,2] 王涛[1,2] 陈良舟 QI Xuyao;WANG Tao;CHEN Liangzhou(Key Laboratory of Gas and Fire Control for Coal Mines,China University of Mining and Technology,Xuzhou 221116,China;2 School of Safety Engineering,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]中国矿业大学煤矿瓦斯与火灾防治教育部重点实验室,江苏徐州221116 [2]中国矿业大学安全工程学院,江苏徐州221116

出　　处：《煤炭学报》2022年第3期1098-1109,共12页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(52174219,51774275,U1810106)。

摘　　要：大规模高强度回采和深部开采常导致顶部裂隙煤岩体失稳、漏风及其次生灾害。钻孔注浆是封堵裂隙和加固煤岩体的主要手段之一。由于煤岩裂隙高位注浆研究相对滞后,井下高位注浆施工设计缺少足够的依据。为探究煤岩裂隙高位注浆浆液扩散规律,以任意倾斜有限边界的光滑平板裂隙和宾汉流体为研究对象,建立裂隙高位注浆扩散数学模型并进行数值模拟求解,分析不同裂隙倾角和注浆速率下浆液在裂隙流动过程中的扩散锋面、流量分配及压力场变化规律;在此基础上,建立浆液高位流动数学模型,并推导恒定注浆速率工况下的解析解。研究结果表明:根据扩散锋面的演变规律,浆液流动过程可分为自由扩散阶段、过渡阶段和受限堆积阶段3个阶段。裂隙倾角对高位扩散距离的影响程度随着流动阶段的演化逐渐减小,注浆流速对高位扩散距离的影响程度随着流动阶段的演化逐渐增大。过大的裂隙倾角加大了高位流量的损耗并加快了流动阶段的转变,而过大的注浆速率减缓了高位流量的损耗并加快了流动阶段的转变。注浆速率和裂隙倾角的增大均会导致注浆压力增加,且在浆液进入受限堆积阶段后注浆压力发生突变。以高位流动扩散形态的等效圆半径临界状态为界,高位流动可划分为扩散阶段与堆积阶段,不同阶段内反演得出的等效圆心角与注浆速率、裂隙倾角和注浆时间具有较好的相关性。根据对比分析结果,浆液高位流动数学模型中相对误差低于20%的样本占97%,相对误差低于10%的样本占78.4%,表明浆液高位流动数学模型具有一定的合理性。浆液在不同时间段内向高位裂隙深部扩散的范围受到裂隙边界影响,只有当底部裂隙空间被填充完毕后浆液才会在裂隙边界的支撑下向深部堆积,因此在现场高位注浆设计时应先探明裂隙区域的边界范围。针对上�The safety risk of top fractured coal and rock mass is caused by large-scale and high-intensity mining and deep mining.Drilling grouting is one of the main methods used to seal fractures and strengthen coal and rock mass.Due to the relatively less research on the theory of high-position grouting for fractures,the design of high-position grouting lacks sufficient theoretical basis.In order to explore the diffusion law of high-position grouting slurry in coal and rock fractures,the smooth plate fractures with arbitrarily inclined finite boundaries and Bingham fluids were taken as the research objects,and the mathematical model of high-position grouting diffusion in fractures was established.The ANSYS FLUENT numerical software was used to numerically solve the mathematical model.The diffusion front,flow distribution and pressure field variation of slurry in the process of fracture flow under different fracture inclination angles and grouting rates were studied.Based on this,the mathematical model of slurry high-position flow was established,and the analytical solution under the condition of constant grouting rate was derived.The research shows that based on the evolution law of the diffusion front,the flow process can be divided into three stages:the free diffusion stage,the transition stage and the restricted accumulation stage.The influence of the fracture dip angle on the high-position diffusion distance gradually decreases with the evolution of the flow stage,and the influence of the grouting flow rate on the high-position diffusion distance gradually increases with the evolution of the flow stage.Excessive fracture inclination increases the loss of high-position flow and accelerates the transition of flow stage,while excessive grouting rate slows down the loss of high-position flow and accelerates the transition of flow stage.The increase of grouting rate and fracture inclination will lead to the increase of grouting pressure,and the grouting pressure changes abruptly after the slurry enters the restricted accu

关 键 词：高位注浆 裂隙倾角 注浆速率 高位流动 扩散锋面 

分 类 号：TD313[矿业工程—矿井建设]