土工织物-非稳定土体反滤系统中滤饼的研究

在土-土工织物组成的反滤系统中,如果被保护土是非稳定土,则在渗流作用下被保护土中会有大量细粒土发生移动,很容易在织物与土层的交界面上形成一层薄滤饼,滤饼的厚度及渗透系数成为影响系统反滤效果的重要因素。根据多孔介质中的渗流与沉积理论,研究了在非稳定土体渗滤过程中,随着细粒土的迁移滤饼的厚度与织物厚度及渗透系数、外部压力等因素之间的关系,并给出了解析表达式。

Study on Filter Cake in the Filtration System of Geotextiles-Unstable Soils

In the soil-geotextile filtration system,a large amount of fine particles will migrate under the drag forces exerted by the flow if the soil is internally unstable.A layer of thin filter cake is prone to be formed between the interface of soils and geotextiles.The thickness and permeability coefficient of the cake become the important factors affecting the filtration effect.Based on the theory of seepage and sediment in the porous medium,the relations between the cake's thickness and other factors such as geotextiles thickness and permeability coefficient,outside pressure,fine particles content are studied during the migration of fine particles in the process of unstable soils' filtration.The analytical expressions are given.