大坝基岩单裂隙灌浆流固耦合模拟研究

Fluid-Solid Coupling Simulation of Single Fracture Grouting in Dam Bedrock

单裂隙是构成裂隙网络的基本元素,对浆液在单裂隙中扩散规律的研究是研究浆液在裂隙网络中扩散的基础.目前灌浆数值模拟研究主要集中在特定参数的取值对数值模拟结果的影响以及数值模拟与模型试验结果的对比,且在考虑流固耦合作用对实际灌浆的影响时均采用二维模型.本文通过构建三维单裂隙特征模型,以对实际灌浆效果影响显著的灌浆压力、裂隙宽度和裂隙倾角等3个因素为研究对象,基于三维离散元方法进行了考虑流固耦合作用的单裂隙灌浆数值模拟参数的敏感性分析.研究结果表明:流固耦合作用对于数值模拟结果的影响随灌浆压力的增大而增大,随裂隙宽度的增大而减小,基本上不会随裂隙倾角的变化而改变.以上结论对于指导基岩裂隙灌浆具有一定的理论和现实意义.

Single fracture is the basic element of fracture network,and the study of the diffusion rule of grout in single fracture is the basis of the study on fracture network.At present,the numerical simulation of grouting mainly focuses on the influence of specific parameter values on the numerical simulation result,and comparison between numerical simulation and model test results,and with the effect of fluid-solid coupling function on the practical grouting considered,two-dimensional model is often adopted.In this paper,by constructing three-dimensional single fracture feature model,three factors that notably affect the actual grouting,i.e.grouting pressure,fracture width and fracture angle were taken as the research objects.Based on three-dimensional discrete element method,the sensitivity analysis of numerical simulation parameters of single fracture grouting was carried out in which the fluidsolid coupling function was considered.The results show that the effect of fluid-solid coupling function on the numerical simulation results increases with the rise of grouting pressure and decreases with the increase of gap width,whereas fracture angle has little influence on it.The above conclusions have some theoretical and practical significance for guiding the bedrock fracture grouting.