黄土塬非饱和黄土增湿变形特性及结构性研究
Study on Moistening Deformation Characteristic and Structure of Unsaturated Loess in Loess Tableland

为了研究黄土塬地区非饱和黄土增湿变形特性及其与结构性的关系，选取庆阳市西峰区某建筑场地土样，对其进行了不同含水率下的黄土固结试验研究，讨论了湿陷系数与压力、初始含水率及初始结构强度的关系。结果表明：不同浸水压力作用下，湿陷系数随初始含水率的增大基本呈现递减趋势；高压力处增湿湿陷性强，低压力处增湿湿陷性弱；黄土结构强度随初始含水率的增大呈降低趋势，且在含水率增大初期，黄土结构强度降低速率较大，后期速率减缓；黄土湿陷前后土体的微结构发生了明显变化，形成了较稳定的次生结构。
In order to study the moistening deformation characteristics of unsaturated loess in loess tableland area and its relation to structure, the soil samples of a building site in Xifeng district of Qingyang city were selected to study the loess consolidation under different water contents. The relations between collapsibility coefficient and pressure, initial moisture content and initial structural strength were discussed. The study results show that the collapsibility coefficient has a decreasing trend with the increase of initial water content under different soaking pressures. The humectation collapsibility is strong with high pressure, and weak with low pressure. The structural strength of loess decreases with the increase of initial water content. The structural strength of loess decreases quickly at the early stage of water content increasing, and decreases slowly at later stage. The microstructure of loess soil has changed obviously after collapsibility, and a more stable secondary structure is formed