黄土湿化特性的三轴试验研究

The Triaxial Test Study of Loess Wetting Properties

研究目的:本文旨在通过三轴试验,研究黄土湿化应力应变关系、强度特征及影响因素。研究方法:通过等围压固结湿化试验和三轴剪切湿化试验进行研究。研究结果:获得不同围压条件下固结湿化变形随时间变化规律,初始含水量、压实度的影响规律;获得不同应力水平下湿化应力应变关系、剪切湿化变形规律以及湿化对强度的影响等成果。研究结论:(1)湿化变形受初始含水量及压实度的影响很大;(2)湿化条件与不浸水条件下,应力-应变关系均表现为应变硬化特性;(3)剪切湿化体积变形随应力水平的增加而减小,轴向变形随应力水平的增大而增大;在同一应力水平下,体积变形与轴向变形均随平均主应力的增大而减小;(4)湿化不仅降低了黄土的强度,也降低了黄土达到破坏时的应变。

Research purposes： By using triaxial test, this paper researches the tress -train relationship, strength property of loess due to wetting, strength characteristics and influence factors. Research methods： Based on the tests under isotropic consolidation and triaxial shear, the wetting properties of loess are obtained. Research results： The strain - time relationship, the influences of initial moisture content and dry density under isotropic consolidation are obtained. The tress - train relationship varying with tress level, the properties of train, strength property of wetting loess under triaxial shear are obtained. Research conclusions： （1） The tremendous influence on humidification deformation by initial moisture content and compaction degree; （2） The stress - strain relationship should behave as strain hardening characteristics under the conditions of humidification and non - soaking ; （3）The shearing humidification volumetric deformation decreases with the increasing of stress level while the axial deformation increases with the increasing of stress level ; Under the same stress level, both the volumetric deformation and axial deformation decrease with the increasing of average main tress; （4） The humidification decreases not only the strength of loess but also the strain of loess when achieving failure.