基于DEM-CFD耦合的潜蚀细观数值模型研究

Study on Suffusion Mesoscopic Numerical Model Based on DEM-CFD Method

为探讨潜蚀发生后细颗粒流失与土骨架变形之间的内在细观机制。基于离散元(DEM)和计算流体动力学(CFD)耦合的方法,构建了潜蚀细观数值模型,分析了内部不稳定土体的初始细颗粒含量和相对密实度对潜蚀发生后土体内部应力传递结构、土骨架变形的细观影响机制,发现初始细颗粒含量和相对密实度显著影响土体内部的应力传递结构。初始细颗粒含量越高,相对密实度越大,发生潜蚀后,越容易诱发土体内部应力传递结构的失稳,造成土骨架明显变形。实际工程中,应重视初始细颗粒含量和相对密实度均较高的内部不稳定土体,此类土体一旦发生潜蚀,更容易诱发地基变形。

In order to explore the mesoscopic mechanism of fine particle loss and deformation of soil skeleton after suffusion,a suffusion mesoscopic numerical model was established based on discrete element method(DEM)and compu-tational fluid dynamics(CFD).The influences of initial fine particle content and relative density on stress transmission within soil and deformation of soil skeleton after suffusion were investigated for internal unstable soils.The results indi-cate that the initial fine particle content and relative density have significant effects on the stress transmission within soil.The higher the initial fine particle content and the relative density are,the more likely that suffusion would induce the in-stability of stress transmission within soil and obvious deformation of soil skeleton.In practical engineering,the unstable soil with high initial fine particle content and relative density should be paid more attention,because once suffusion initi-ates within this kind soil,it is easier to cause the deformation of soil skeleton.