非饱和膨胀土脱湿过程中的弹性模量研究  

Study on Elastic Modulus of Unsaturated Expansive Soil During Dehumidification Process

作　　者：席人双[1] XI Renshuang(China Railway Siyuan Survey&Design Group Co.Ltd.,Wuhan 430063,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《铁道建筑》2024年第1期14-19,共6页Railway Engineering

基　　金：国家重点研发计划(2021YFB2600400)。

摘　　要：现有的理论与测试方法通常没有考虑非饱和作用对膨胀土弹性模量的影响,在处理降雨问题时会产生较大的误差。针对这一问题,本文研究了膨胀土在脱湿过程中的收缩变形特征,同时采用弯曲元以及应变控制仪获得了在小变形条件和有限变形条件下膨胀土的弹性模量与含水率的变化关系。结果表明:随着土样饱和度降低,膨胀土发生了明显的收缩变形;小变形弹性模量远大于有限变形弹性模量,且土样的小变形弹性模量随着饱和度的降低迅速增大,而有限变形弹性模量则随着饱和度的降低变化幅度很小;含水率或基质吸力对非饱和土弹性模量的影响趋势与应变水平密切相关。The existing theories and testing methods often lack consideration of the influence of unsaturated effects on the elastic modulus of expansive soil,which could result in significant errors when dealing with rainfall problems.In response to this issue,this article studied the shrinkage deformation characteristics of expansive soil during the dehumidification process,and obtained the relationship between the elastic modulus and water content of expansive soil under small deformation conditions and finite deformation conditions using bending elements and strain control instruments.The results show that as the saturation of the soil sample decreases,the expansive soil undergoes significant shrinkage deformation.The small deformation elastic modulus is much greater than the finite deformation elastic modulus,and the small deformation elastic modulus of the soil sample increases rapidly with the decrease of saturation,while the finite deformation elastic modulus changes very little with the decrease of saturation.The influence trend of moisture content or matrix suction on the elastic modulus of unsaturated soil is closely related to the strain level.

关 键 词：非饱和膨胀土 弹性模量 试验研究 弯曲元 小变形 有限变形 

分 类 号：U213.14[交通运输工程—道路与铁道工程] TU443[建筑科学—岩土工程]