伊犁黄土湿陷变形特性研究

Study on Collapsible Deformation Characteristics of Yili Loess

湿陷是黄土地区建筑物发生破坏的重要原因,伊犁黄土厚度大、湿陷性强烈,且天然密度小、含水率低极适合湿陷变形研究。通过单线法试验研究伊犁黄土的湿陷变形特性随含水率、干密度、深度及压力变化关系,通过双线法湿陷试验研究不同初始含水率对伊犁黄土湿陷特性的影响规律。结果表明:伊犁黄土湿陷强烈,浅层处湿陷性较严重,湿陷系数随着深度的增加而减小;一定深度下,伊犁黄土的湿陷系数随压力的增加呈增大的变化趋势,初始含水率小于8.6%时,湿陷系数与压力的关系近似呈S型曲线关系,初始含水率大于9.4%时,湿陷系数与压力的关系曲线出现峰值。伊犁黄土具有强烈的湿陷性,在不同深度、压力和初始含水率情况下表现出不同的湿陷性和湿陷敏感性,研究伊犁黄土湿陷变形特性,可为湿陷性黄土地区黄土研究和工程建设提供参考借鉴。

Collapsible of the foundation is an important reason for the damage of buildings in the loess area.Ili collapsibility loess has the characteristics of big thickness and strongly collapsible,the natural small density,low moisture content,and it is extremely suitable for study on collapsible deformation.The collapsibility law of Yili loess along the change of moisture content,dry density,depth and pressure of foundation was studied by the single-line method,and the relationship between the collapsibility of Yili loess at different depths and moistening water content was studied by the double-line humidification and collapsibility test.The results showed that Yili loess was strongly collapsible,and the shallow layer was strongly collapsible.The collapsibility coefficient decreased with the increase of depth.At the same depth,the ili loess collapsibility coefficient increases with the increase of the pressure.When moisture content was less than 8.6%,the relationship between collapsible coefficient and pressure approximation showed an s-shaped curve.When moisture content is more than 9.4%,the relationship between collapsible coefficient and pressure appeared curve peak.Yili loess was strongly collapsible,and it showed different collapsibility and collapsibility sensitivity under different depths,water content,pressure and saturation.The characteristics of the ili loess collapsibility deformation can provide a reference for the research on the loess in collapsible loess regions and engineering construction.