基于微细观参数演化的工程废浆化-力-电渗耦合作用机理及固结模型

The field dispose of engineering waste slurry (super soft soil) will lead to soil harding, which has a negative influence on the surrounding environment. The coupling of chemical-mechanical-electroosmosis can effectively and rapidly separate solid and liquid in engineering waste slurry, and realize harmless treatment of engineering waste slurry. From the perspective of microscopic-microscomic parameter of engineering waste slurry, regard chemical-mechanical-electroosmosis model test as the basis, combining with system theory analysis and numerical simulation, this proposal plan to obtain the main research contents and innovation points are as follows. Reveal a variety of chemical agents with different ion concentration and pH value influencing mechanism on microscopic-microscomic parameter of engineering waste slurry (surface charge density, zeta potential, moisture content) . Build a quantitative relationship between zeta potential and effective porosity ratio - electroosmotic permeability; Based on the evolution law of microscopic-microscomic parameter of engineering waste slurry, the development of pore water pressure, and settlement deformation process, the coupling mechanism of chemical-mechanical-electroosmotic of engineering waste slurry is expounded; Considering the influence of ion migration and electrolysis reaction on the evolution of microscopic-microscomic parameter and their macroscopic characteristics parameter, a coupling consolidation model of chemical-force-electroosmosis is built, which used to describe the development of pore water pressure and settlement deformation in the process of engineering waste slurry treatment under various working conditions. The research results have an important theoretical and practical significance on the multi-disciplinary innovation of the coupling of chemical-mechanical-electroosmosis in the engineering waste slurry treatment.

工程废浆(超软土)的场地倾倒会导致土壤板结，对周围环境造成负面影响。采用化-力-电渗耦合方法可对工程废浆进行有效快速地固液分离，实现工程废浆的无害化处理。基于此，本项目从工程废浆微细观参数的角度出发，以化-力-电渗模型试验为基础，结合系统的理论分析和数值模拟，主要研究内容与创新点如下：揭示多种化学药剂不同离子浓度和pH值对工程废浆微细观参数(表面电荷密度、zeta电位、水分组成)的影响机制，构建zeta电位和有效孔隙比-电渗渗透系数的定量关系式；基于工程废浆的微细观参数演化规律、结合孔压发展和沉降变形过程，阐明工程废浆的化-力-电渗耦合作用机理；考虑离子运移和电解反应对微细观参数演化及其宏观特性参数的影响，构建化-力-电渗耦合固结模型，描述各工况条件下处理工程废浆过程中孔压发展和沉降变形过程。研究成果对于化-力-电渗耦合方法在工程废浆处理中的多学科交叉创新研究具有重要的理论与实际意义。

随着交通强国建设的推进，在工程建设过程中会面临大量的废浆等软土处理工程，采用传统的固结压缩处理细颗粒土存在效率低和效果欠佳等问题。虽然，相较于固结压缩法，电渗法处理细颗粒土的效率更高。但是，联合使用固结压缩和化学药剂更容易提升其处理效果。基于此，本研究开展了针对废浆和软土的化-力-电渗耦合研究。取得的研究成果如下：1.从微观颗粒角度揭示了离子絮凝剂对膨润土废浆絮凝的作用机制，构建了电渗渗透系数与zeta电位和液塑限的相关关系；2.结合焦耳热原理、离子运移、电解反应和电渗固结基本理论，明确了温度对电渗排水的促进作用，阐明了离子运移和电解反应与电渗固结的正相关性，揭示了化-力-电渗耦合作用机制，并提出石墨粉、跟进阳极和聚丙烯纤维等电渗排水增强方法；3.构建了电渗过程中裂缝和体缩发生的临界条件，解析了电渗过程中裂缝和体缩发生的机理，确定了体积差现象与电势梯度存在正相关性，描述了渗流边界对试样孔压演化的影响规律，获取了土样含水率和孔压分布规律的相关性。研究成果有助于进一步推动电渗技术在工程废浆和软土处理中的应用，具有重要的科学意义和工程应用价值。