吸附模式及固结变形对溶质运移规律的影响研究

Study on the effects of adsorption modes and consolidation deformation on solute transport

目前关于溶质在变形土体中运移规律的研究相对较少,但是荷载作用又是实际工程中必须考虑的因素。基于比奥固结理论和溶质运移理论,建立渗流场、应力场和浓度场耦合的溶质运移模型,并采用有限差分法对溶质在变形土体中的运移规律进行研究。此外,许多学者在研究溶质运移规律时,多数情况下采用线性吸附模式,但是细粒土对金属离子、有机物或者高浓度溶质的吸附多表现出较强的非线性,因此研究了不同吸附模式作用下溶质的运移规律。研究结果表明,固结变形对溶质的运移过程具有持久性的阻滞作用,导致了溶质运移深度的减小;吸附模式对溶质运移规律没有本质的影响,但是吸附模式对溶质运移的快慢有较大影响,并且随着运移时间的增加,吸附模式对溶质运移快慢的影响不断增大。

Up to date, there are still few reports on the study of solute transport in deforming soils. However, the loading must be considered in practical engineering. Based on the Biotb consolidation theory and the solute transport theory, the solute transportation model with coupled seepage field, stress field and concentration field was established, and then the finite difference method was used to simulate the solute migrating process in the deforming soils. In addition, when studying the solute migrating process, many scholars generally adopt the linear adsorption mode to describe the adsorption property of soil. Because the fine-grained soils always exhibit strong non-linear sorption to metal ions, organic matters or highly concentrated solution, the migrating process of solute under different adsorption mode was analyzed. The results show that the consolidation deformation has a permanent retarding effect on the transport process of solute, which leads to the decrease of transport depth of solute. The adsorption mode does not have the essential influence on the transport law of solute, but it has apparent impact on the transport velocity of solute, and moreover the influence gradually increases with time.