基于水分转化模型的膨胀土复合改性机理研究

The interaction between expansive soil and water will induce the swell-shrink potential, which may cause the deterioration of soil structure and strength. The key factor for expansive soil modification is the water. In this project, a combined usage of ionic soil stabilizer with inorganic material is proposed for expansive soil modification. Based on the view of water conversion, a laboratory method to quantitatively describe the water conversion state is firstly proposed. On this basis, the analysis into the process of water conversion amount and rate corresponding with the hydration and hardening reaction of inorganic materials is performed, and therefore, a dynamic relationship between the water transformation pattern and evolution of soil pore structure and strength could be established. With the analysis of physicochemical parameters of swelling clay mineral, the mechanism of water potential energy transformation and its effect on the control of the hydration process of inorganic materials could be understood, and correspondingly, collaborative mechanism between the two stabilizing materials could be revealed. Based on the above research achievement, a micro-swelling model would be set up ,which take fully account of water、soil structure and physicochemical effect. The long-term stability of stabilized expansive soil exposed to different form of moisture environment is finally studied. This project achievement would provide a strong promotion to the engineering construction in expansive soil area and problematic soil stabilization theory. Therefore, it possesses enormous academic value and broad prospect in engineering applications.

膨胀土与水相互作用中显现的强烈胀缩性是诱发土体结构劣化、强度衰减的根源，水分调控是膨胀土改良加固的关键。本项目提出采用离子土固化剂联合无机材料复合改性膨胀土的新方法，以水分转化为切入点，首先实验建立膨胀土水分转化形态的定量界定方法，在此基础上，分析复合调控过程中土体孔隙内部不同形态水分的转化量、转化率与无机材料水化反应及硬化过程的对应机制，建立改性过程水分转化模式与结构、强度演化的动态关联；通过对膨胀性粘土矿物表面水合物化参数分析，明晰复合改性下水分势能转变机理及其对无机材料水化历程的控制作用，进而揭示改性材料之间的协同机理；构建考虑水分-结构-物化作用多因素耦合的改性土微细观膨胀模型，并评价改性土在不同水分形式作用下长期稳定性。研究可为膨胀土治理的实践提供科学依据和理论支撑，对推动膨胀土地区工程建设及特殊土改良理论发展有着重要价值和现实意义。

膨胀土与水相互作用中显现的强烈胀缩性是诱发土体结构劣化、强度衰减的根源，水分调控是膨胀土改良加固的关键。本项目提出采用离子土固化剂联合无机材料复合改性膨胀土的新方法，以水分转化为切入点，首先实验建立膨胀土水分转化形态的定量界定方法，在此基础上，分析复合调控过程中土体孔隙内部不同形态水分的转化量、转化率与无机材料水化反应及硬化过程的对应机制，建立改性过程水分转化模式与结构、强度演化的动态关联；通过对膨胀性粘土矿物表面水合物化参数分析，明晰复合改性下水分势能转变机理及其对无机材料水化历程的控制作用，进而揭示改性材料之间的协同机理；构建考虑水分-结构-物化作用多因素耦合的改性土微细观膨胀模型，并评价改性土在不同水分形式作用下长期稳定性。研究可为膨胀土治理的实践提供科学依据和理论支撑，对推动膨胀土地区工程建设及特殊土改良理论发展有着重要价值和现实意义。