纳米电化学技术用于软土加固的机理研究

The consolidation/stabilization of soft soil foundation is of great importance to the construction of buildings, railroads, airports, roads, bridges, slopes, etc. As such, it has been one of the issues given due attention in geotechnical engineering. The last decade has seen good advances in the use of electrochemical techniques for the research and application of geotechnical engineering. Recent years have also seen rapid development of nanotechnology in civil engineering, among which the report of using electrically-driven nanoparticles to rehabilitate concrete features practical enlightenment significance. The use of nanotechnology in the electrochemical treatment of soft soil foundation or weak soils has not been reported. As such, on the basis of our existing work in nano-modified concrete, electrochemical rehabilitation of concrete, FEM modeling of ionic transport in porous media, etc., this study will identify/select a few types of chemicals and nanomaterials and electrially inject them into a few selected typical soft soils. Through their interactions with soil gels and electrochemical reactions, this will lead to the extraction of moisture in soil, the filling of pores in soil, and the optimization of soil chemistry and microstructure. This applied fundamental study will combine multiple chemical and electrochemical characterization means with conventional geotechnical materials testing methods. It will combine lab experiments with finite element method (FEM) modeling, unravel the mechanisms underlying nano-electrochemical consolidation of weak soils, and provide a low-cost, non-toxic and highly effective soil stabilization technique. Ultimately, this stuy will contribute to the advances in the relevant knowledge base and to the development of national economy.

软土地基加固处理对建筑、铁路、机场、道桥、边坡等施工建设有重要意义，因此是岩土工程研究的最为关注的问题之一。在过去十年电化学技术于岩土工程的研究和应用均取得了良好的发展。纳米科技近年来在土木工程中也取得了迅猛发展，特别是外加电场驱动纳米颗粒修复混凝土的报道对于岩土工程很有启发意义。纳米科技在软土地基电化学加固中的研究尚未见报道。本研究在我们现有的纳米改性混凝土、电化学修复混凝土、多孔介质中离子运输有限元模拟等工作基础上，选择若干种化学物质和纳米材料，通过外加电场注入到多种典型软土中，经过与土壤胶体的相互作用和电化学反应，实现土壤中水分的排出、土壤孔隙的填充以及土壤化学成分和微观结构的优化。该应用基础研究将多种化学和电化学表征手段与常规岩土材料测试方法相结合，将实验与有限元相结合，探索电化学方法加固软土的机理，提供低成本、无毒、高效的软土加固技术，为科技进步和国民经济发展做出一定贡献。

软弱土地基加固处理对建筑、铁路、机场、道桥、边坡等施工建设有重要实际意义，因此是岩土工程研究的最为关注的问题之一。在过去十年电化学技术于岩土工程的研究和应用均取得了良好的发展。本应用基础研究项目立足于经济发展中迫切需要解决的岩土与基础工程技术挑战，探索了一系列创新性科学问题。本项目研究了在多种典型软弱土中注入各种电解质和纳米结构颗粒，借助于电泳、电渗、电迁移等动电学现象，加快了结合水的排出，实现对软土地基的改造与加固。通过对典型的软粘土样本进行实验室测试，结合有限元模拟阐明了电化学技术加固软土的关键过程有关机理并验证了用新一代纳米电化学技术更为有效地加固软弱土的假设，同时揭示了纳米材料的几何特征尺度、基本带电特性等物理性能等电渗排水的影响机理。因此，本项目的研究成果提供了基于纳米材料和技术的低成本、无毒、高效的软土电渗加固技术，为科技进步和国民经济发展做出一定贡献。