泥水盾构施工中泥浆在高压作用下侵入土层形成不同状态的泥膜,泥膜的形成机理复杂,但其状态划分依据相对简单。基于离散元程序YADE编制了流体与颗粒相互作用及粒间长程引力作用模型,从粒径比、粒间范德华力、流体初始流速以及泥浆颗粒密度几个方面分析了泥浆侵入土层初始恒速阶段的堆积状态,确定土层最紧密堆积对应的泥膜状态理论下限值。采用静置后的泥浆侵入土层模型试验分析了两组土层粒径的泥膜状态,表明粒径比对泥膜状态的影响与离散元分析结果、泥膜状态划分理论相吻合。初步建立了泥膜形成过程的宏细观联系,弥补了传统过滤理论和离散元法未考虑颗粒侵入土层动态形成泥膜的不足。 During the construction of slurry shield, the mud intruded into the soil under the action of high pressure to form the mud membrane in different states. The forming mechanism of the mud membrane is complex, but its state division basis is relatively simple. Based on the discrete element program YADE, the interaction between fluid and particle and the long-range gravitational interaction between particles were studied. The initial constant velocity stage of mud invasion into soil was analyzed from the aspects of particle size ratio, intergranular van der Waals forces, initial fluid velocity and mud particle density Of the accumulation of state, to determine the soil layer closest accumulation corresponding to the lower limit of mud film theory. The model test of muddy soil invasion after standing was used to analyze the muddy state of the two groups of soil particle size. The results show that the effect of particle size on the muddy state is consistent with the discrete element analysis and muddy state division theory. The macroscopic and microscopic relations of the formation process of the mud membrane were preliminarily established, which made up the deficiency of the traditional filtration theory and the discrete element method without considering the dynamic invasion of the clay into the soil layer.