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作为建筑材料的黄土在工程建设中大多经过压实处理,其增湿变形特性与工程安全密切相关。已有的对黄土增湿变形性质的研究,基本上是针对原状黄土开展的,对压实黄土较少涉及。通过双线法增湿湿陷试验,对压实黄土在增湿条件下的压缩及增湿变形性质进行了较系统的研究,并进行了压缩和湿陷变形影响因素的方差分析。结果表明:①随增湿含水率的增加,压实黄土的压缩性增大,湿陷性减小,压实度越小,这种效应越明显;不同压力下,湿陷变形对增湿的敏感性不同;②随增湿含水率的增加,增湿变形起始压力减小,增湿变形终止压力增大,增湿变形压力区间增大,可用增湿变形系数反映已有增湿水平下土体湿陷性的退化程度;③方差分析表明,相同增湿含水率下,压实黄土最终变形仅受最终压力的影响,加荷路径、浸水路径及两者的耦合对其影响很小;④未浸水饱和压缩时,密实度、初始含水率和压力,以及它们的交互作用均对压缩变形有显著影响,压力的影响最大,其次是密实度和初始含水率;与未浸水情况不同的是,浸水饱和压缩时初始含水率的影响很小;⑤增湿含水率、压力和密实度,以及它们的交互作用均显著影响压实黄土的湿陷性,其中增湿起始含水率的影响最大,密实度次之,压力最小。
As the loess of building materials, most of the loess in the construction has been compacted, and its humidification deformation characteristics are closely related to the project safety. The existing research on the deformation and deformation properties of loess is basically carried out on undisturbed loess and less involved in the compaction of loess. By means of double-line humidification and collapsibility test, the compression and humidification deformation properties of compacted loess under humid conditions were studied systematically, and the variance analysis of factors affecting compression and collapse deformation was carried out. The results show that: (1) With the increase of moisture content, compressibility of compacted loess increases, collapsibility decreases, and the compaction degree becomes smaller. The effect is more obvious under different pressures. With the increase of moisture content, the initial pressure of humidification deformation decreases, the final pressure of humidification deformation increases, and the range of humidification deformation pressure increases. The humidification deformation coefficient can be used to reflect the existing level of humidification The analysis of variance shows that the final deformation of compacted loess is affected only by the final pressure at the same moisture content, and the influence of the loading path, the water-immersion path and the coupling between the two is negligible. (4) The density, initial water content and pressure, as well as their interaction, all have significant influence on the compressive deformation when saturated water is not saturated, the influence of pressure is the greatest, followed by the density and the initial water content; , And the effect of initial moisture content in submerged saturated compression is small. (5) Moisture content, pressure and density, as well as their interaction, significantly affect the collapsible loess collapsibility, of which the initial moisture content is the most affected , Followed by the density, the minimum pressure .