寒旱区硫酸盐渍土路基结构损伤破坏机理研究综述

Review on Damage Mechanism of Sulphuric Acid Soil Roadbed Structure in Cold and Arid Regions

摘要: 硫酸盐渍土在我国西北寒旱区分布广泛，路基病害严重，对道路工程建设不利。主要对外部环境作用对路基结构的变形影响及其损伤机理研究进行了综述。寒旱区的道路病害主因是土体的盐冻胀变形和水泥基材料在硫酸盐参与下的化学侵蚀。学者们探究了含盐量、含水量、压实度、温度等因素对路基盐胀的影响；依据寒旱区地理气候特征，模拟干湿循环和盐冻融循环作用研究了路基盐冻胀、强度、微观结构变化规律；随着研究不断深入，技术手段不断提高，学者们利用COMSOL等有限元软件来模拟路基环境，探究水、盐、温、力的多场耦合环境作用的盐渍土路基损伤破坏机理，借助CT、SEM、XRD来观测结构内部微观变化特征。根据目前的研究成果，今后可多做现场试验研究、结晶压力的定量研究和多场耦合作用模型建立的探究。

Abstract: Sulfuric acid saline soil is widely distributed in the cold and arid areas of Northwest China, and the subgrade diseases are serious, which is unfavorable to the road engineering construction. The main causes of road diseases in cold and arid regions are salt frost heave deformation of soil and chemical erosion of cement-based materials with sulfate participation. Scholars have explored the influence of salt content, water content, degree of compaction, temperature and other factors on subgrade salt swelling. According to the geographical and climatic characteristics of cold and arid regions, the dry-wet cycle and salt freezing-thawing cycle were simulated to explore the changes of frost heave, strength and microstructure of subgrade salt. With the deepening of research and the improvement of technical means, scholars also used finite element software such as COMSOL to simulate the subgrade environment, explored the microscopic change characteristics inside the structure with the help of CT, SEM and XRD, and explored the damage mechanism of saline soil subgrade under the multi-field coupling environmental action of water, salt, temperature and force. According to the current research results, more field experiments can be done in the future, and more research can be done in the quantitative study of crystallization pressure and the establishment of multi-field coupling action model.