基于CFD-DEM方法的砂土注浆微观机理研究

Micromechanical Investigation of Grouting in Sand Based on CFD-DEM Approach

砂土注浆过程可认为是粘性流体在多孔固体颗粒介质中的流动、扩散及凝固的过程,该过程涉及到流-固耦合及浆液物理化学性质复杂等特征。文章创新性地通过采用计算流体力学-离散元的耦合方法(CFD-DEM)模拟砂土注浆过程,以DEM模拟砂土颗粒骨架,以CFD模拟浆液,通过描述浆液与土颗粒之间的相互作用,再现了砂土注浆过程中浆液在土颗粒间隙中的填充、扩散规律。通过运用砂土注浆数值试验,分析了注浆速度、浆液粘度、土层孔隙率等因素对压力的影响规律,为阐明砂土注浆机理及宏-细观特性提供理论支撑。

The process of sand grouting is a process of flow,diffusion and solidification of viscous fluid in porous media,which involves fluid-solid coupling and complex physical and chemical properties of the slurry.In this paper,the computational fluid dynamics-discrete element coupling method(CFD-DEM)is used to simulate sand grouting,the skeleton of sand particles is simulated by DEM,and the grout is simulated by CFD.By describing the interaction between grout and soil particles,the law of filling and diffusion of grout in soil during sand grouting is reproduced.The influence of grouting speed,slurry viscosity,soil porosity and other factors on the grout pressure are analyzed through the numerical experiments of sand grouting,which could provide theoretical support for elucidating sand grouting mechanism and macro-micro characteristics.