改性膨胀土胀缩变形的研究进展

Research Progress on Swelling Shrinkage Deformation of Modified Expansive Soil

摘要: 膨胀土因其吸水膨胀、失水收缩的特性往往会对工程结构造成不可逆的损伤，改性膨胀土便是通过添加改性材料来改变其微观结构与力学性质，改善土体的胀缩特性，解决因胀缩变形而引发的膨胀土结构破坏问题。在以往的研究中，国内外学者通过对膨胀土力学性质与内部结构的探索，逐步建立起了以晶层扩张理论和双电层理论为主流观点的膨胀土胀缩机理，并采用物理、化学、生物(MICP技术)等单向或多种方法复合的方式对膨胀土的胀缩性质进行改良。将改良的原料慢慢地转向了煤矸石、粉煤灰等大型工业废料，取得了显著的研究成果，亦符合现代的绿色健康和可持续发展的理念，在积极改善了土体结构性质的同时，为我国工业废料的二次利用也提供了一个不错的解决方案。

Abstract: Expansive soil often causes irreversible damage to the engineering structure due to its characteristics of water absorption expansion and water loss shrinkage. Modified expansive soil changes its microstructure and mechanical properties by adding modified materials, improves the expansion and contraction characteristics of soil, and solves the structural damage problem of expansive soil caused by expansion and contraction deformation. In previous studies, domestic and foreign scholars have gradually established the swelling and shrinking mechanism of expansive soil based on the crystal layer expansion theory and the double electric layer theory through the exploration of the mechanical properties and internal structure of expansive soil, and improved the swelling and shrinking properties of expansive soil by using one-way or multiple methods such as physical, chemical, biological methods (MICP technology). The improved raw materials are slowly turned into large industrial wastes such as coal gangue and fly ash, and remarkable research results have been achieved, which also conforms to the modern concept of green health and sustainable development. While actively improving the structural properties of soil, it also provides a good solution for the secondary utilization of industrial wastes in China.