帷幕注浆逐渐成为矿井水害防治的主要技术手段之一,为解决帷幕工程中注浆孔间距的布设问题，通过室内试验得到帷幕注浆材料单液水泥浆的物理性能参数，采用COMSOL数值软件建立了地下含水层帷幕注浆单液水泥浆扩散数值模型，研究了地下含水层帷幕注浆工程中单液水泥浆的扩散机制。研究结果表明：单液水泥浆水灰比越大，浆液的凝结时间越长黏度越大，而结石率与抗压强度越小，根据所得浆液性能参数针对不同地层特征选取相应水灰比的浆液进行注浆；地下含水层帷幕注浆单液水泥浆的扩散形式以注浆孔为中心的圆形扩散，单液水泥浆的扩散半径随注浆时间的增加而增大，且扩散半径最终趋于稳定，稳定后的浆液扩散半径平均值为10.22 m，浆液扩散的范围可达到20.44 m；单液水泥浆扩散半径的理论计算与数值计算结果较为一致，理论解与数值解之间的误差小于5%，证明作者建立的数值模型用于研究帷幕注浆浆液扩散范围具有一定的可靠性。基于研究结果，选取帷幕注浆孔距为20 m，2排交错布孔，建立有效宽度约为40 m的帷幕墙，以阻隔帷幕墙外侧含水层中地下水向井田内的补给。帷幕墙建造完成后，通过检查孔对受注地层进行取心，得到含有浆液结石体的岩心，实验室测试得到其抗压强度为11.2 MPa，能够满足帷幕墙建设的强度要求，证实帷幕注浆工程中注浆孔间距布设合理。

Curtain grouting has gradually become one of the main technical means for prevention and control of mine water damage. To solve the layout problem of grouting hole spacing in curtain engineering,the physical properties of the grouting material were obtained through laboratory experiments,and using COMSOL numerical software,the numerical model of pure liquid cement slurry diffusion in curtain grouting of underground aquifer was established. The mechanism of grout diffusion in curtain grouting engineering of underground aquifer was studied. Research results indicates that the larger the water-cement ratio of pure liquid cement slurry,the longer the setting time of the slurry,the greater the viscosity,and the smaller the calculus rate and compressive strength; the diffusion form of curtain grouting for pure liquid cement slurry in the underground aquifer is circular diffusion centered on grouting hole,the slurry diffusion radius increases with the increase of grouting time. The average diffusion radius of the stabilized slurry is 10.22 m,and the distance of slurry diffusion reached 20.44 m. The theoretical and numerical calculation results for the diffusion radius of pure liquid cement slurry are relatively consistent. The error between theoretical solution and numerical solution is less than 5%. It shows that the established numerical model is reliable to study the slurry diffusion in curtain grouting. According to the results of numerical simulation and theoretical calculation,the grouting hole spacing in curtain grouting process is selected as 20 m,and a curtain wall with an effective width of about 40 m is built with two rows of staggered holes to block the recharge of the mine from the aquifer outside the curtain wall. After the curtain wall is constructed,the core containing slurry stone body is obtained through inspection holes,and its compressive strength is 11.2 MPa,which can meet strength requirements of curtain wall construction. It is proved that the grouting hole spacing in curtain grouting project is reasonable.

0 引言

1 工程背景

2 浆液扩散机制

   2.1 浆液性能试验

   2.2 浆液扩散数学模型

3 浆液扩散数值模拟

   3.1 注浆扩散数值模型

   3.2 数值模拟结果及分析

4 理论计算与数值模拟结果分析对比

5 工程应用

6 结论