论文部分内容阅读
国内湖泊疏浚污染底泥堆场一般以较厚的黏土层作为主要防渗层,由于在上覆底泥作用下黏土层会发生较大的固结变形,因此,在研究黏土防渗层中的污染物运移和转化规律时,应该考虑土体变形的影响。基于Gibson一维大变形固结理论和饱和多孔介质中的污染物对流扩散方程,建立了二者耦合的可变形多孔介质中污染物的运移和转化模型,其中首次考虑了土体自重和生物降解作用的影响。利用所建立模型的数值解,研究了在可变形黏土防渗层中的污染物运移和转化规律,同时分析了模型中不同项和主要参数的作用和影响。研究结果表明,土体大变形对黏土防渗层中污染物的运移有着较复杂的影响,一方面土体变形会加速污染物的运移;另一方面土体固结带来的渗透性减小会增加污染物的穿透时间,二者的不同作用取决于众多的影响因素,如土层厚度和吸附作用等。研究结果对于评估天然黏土防渗层对污染物的阻隔作用有重要的指导意义。
Due to the large consolidation deformation of the clay layer under the action of the overlying sediment, the sediment contaminated by lake dredging generally has a thick clay layer as the main impermeable layer. Therefore, in studying the clay impermeable layer When pollutants are transported and transformed, soil deformation should be considered. Based on the Gibson one-dimensional theory of large deformation and consolidation and the convection-diffusion equation of pollutants in saturated porous media, a model for the transport and transformation of pollutants in two-coupled deformable porous media was established. For the first time, Effect of degradation. Based on the numerical solution of the established model, the transport and transformation rules of pollutants in deformable clays are studied, and the roles and influences of different terms and main parameters in the model are analyzed. The results show that the large deformation of soil has a more complicated influence on the migration of pollutants in the clay impermeable layer. On the one hand, soil deformation will accelerate the migration of pollutants; on the other hand, the permeability caused by soil consolidation Reducing the penetration time of pollutants will increase the different effects of pollutants depending on many factors such as soil thickness and adsorption. The research results have important guiding significance for evaluating the barrier function of natural clay impermeable layer to pollutants.