摘要
采用计算机层析成像（CT）技术和常规直剪试验,探讨干湿循环作用下膨胀土的细观结构及其强度变化规律。基于CT数定义损伤变量,据此建立了干湿循环作用引起的结构变化与强度参数变化的联系。研究结果表明：第1~4次干湿循环对膨胀土结构变化影响较大,内部裂隙发育明显;第7、第8次干湿循环对结构影响甚微;经干湿循环作用后,膨胀土的强度衰减主要是黏聚力大幅度降低,而内摩擦角则无明显变化;随着干湿循环次数的增加,试件损伤变量逐渐增加,其细观结构损伤演化是一种非线性累积过程;膨胀土黏聚力与CT损伤变量具有良好的指数衰减关系。
The variations law of meso-structure and shear strength of expansive soil under the condition of dryingwetting cycles were studied with CT technology and normal direct shear experiment. Defining damage variable based on CT number,the relationship of the change of the strength parameters and the structure resulted from drying-wetting cycles was established. The results showed that the influence of the 1st to the 4th times of drying-wetting cycles on the structure of expansive soil was bigger,the development of internal fracture was obviously. The influence of the 7th to the 8th times of drying-wetting cycles on the structure was little. After the drying-wetting cycles,the strength attenuation of expansive soil was mainly decrease of cohesion,and the variation of internal friction angle was not significant. With the increase of drying-wetting cycles,the damage variable of the specimens increased gradually,and the evolution of meso-structure damage was a non-linear accumulating process. CT damage variable of expansive soil with its cohesion had a good exponential function decay relationship.
出处
《工业建筑》
CSCD
北大核心
2015年第8期99-103,共5页
Industrial Construction
基金
长沙理工大学道路结构与材料交通行业重点实验室开放基金资助项目(kfj110205)
