动力湿化作用下高液限红黏土低路堤灾变机理及长期变形研究

The low embankment filled with high liquid limit red clay is affected by vehicle load, rainfall and groundwater. Uneven settlement and road surface cracking often occur, which seriously affects the comfort and safety of driving and causes huge economic losses. The catastrophic mechanism, long-term deformation and control technology of low embankment with high liquid limit red clay under dynamic humidification are worthy of further study. This project starts from the perspective of the coupling of dynamic load and water environment, using the numerical simulation and model test method to analyze the dynamic response and water migration of low embankment with high liquid limit red clay. Through X-ray diffraction, scanning electron microscopy and dynamic triaxial CT simultaneous scanning test reveals the interaction between high liquid limit red clay and water, and the damage mechanism of microstructure under dynamic load and wetting conditions. On the basis of studying the engineering characteristics of high liquid limit red clay, we will build a mathematical model about the seepage strength characteristics and stability critical stress of high liquid limit red clay under dynamic humidification, long-term deformation and damage constitutive relation. The numerical calculation method of long-term deformation of high liquid limit red clay low embankment under dynamic humidification is proposed. The long-term deformation law of low embankment with high liquid limit red clay is studied, and the long-term deformation control technology of low embankment with high liquid limit red clay is formed. The research results will further improve and develop the low-rise embankment prevention and control theory of catastrophe as well as prediction method of long-term deformation under the dynamic humidification, which has significant theoretical and engineering practical significance.

高液限红黏土填筑的低路堤受车辆荷载、降雨及地下水影响，常发生路面开裂与不均匀沉降现象，严重影响行车舒适与安全，造成巨大的经济损失。动力湿化作用下高液限红黏土低路堤灾变机理、长期变形及控制技术值得深入研究。本项目从动荷载与水环境耦合作用的角度出发，采用数值模拟与模型试验方法，分析高液限红黏土低路堤动力响应与水分迁移规律；通过X射线衍射、扫描电镜与动三轴CT同步扫描试验，揭示高液限红黏土与水相互作用及其微观结构动力湿化损伤机理；基于高液限红黏土工程特性，建立动力湿化作用下高液限红黏土渗流强度特性、安定状态临界应力、长期变形与损伤本构关系数学模型；提出动力湿化作用下高液限红黏土低路堤长期变形数值计算方法，研究高液限红黏土低路堤长期变形规律，形成高液限红黏土低路堤长期变形控制技术。研究成果将进一步完善与发展动力湿化作用下高液限岩土体低路堤灾变防控理论与长期变形预测方法，具有重大理论与工程实践意义。

高液限红黏土填筑的低路堤受车辆荷载、降雨及地下水影响，常发生路面开裂与不均匀沉降现象，严重影响行车舒适与安全，造成巨大经济损失。目前，虽在低路堤沉降变形方面有大量研究，但对动力湿化作用下高液限红黏土低路堤灾变机理及长期变形的研究不够深入。本项目拟针对该问题开展以下工作：首先，通过模型试验分析高液限红黏土低路堤动力响应与水分迁移规律。其次，通过扫描电镜与三轴试验揭示高液限红黏土与水相互作用及其微观结构动力湿化损伤机理；基于高液限红黏土工程特性，建立动力湿化作用下高液限红黏土安定状态临界应力与回弹模量预估模型；提出动力湿化作用下高液限红黏土低路堤长期变形计算方法。最后，研究高液限红黏土低路堤长期变形规律，形成高液限红黏土低路堤长期变形控制技术。本项目研究成果对动力湿化作用下高液限岩土体低路堤灾变防控理论与长期变形预测方法具有指导意义。