南京下蜀黄土的非均匀性研究

STUDY ON INHOMOGENEITY OF XIASHU LOESS

下蜀黄土分布在不同高程的多种地貌单元 ,如山顶、阶地、山麓及盆地 ,由黄土层和红土层两部分组成 ,具有成分和结构差异 ,尤其是水稳定性。它是一种非均匀性土层。当其位于地下水位以上或开放性状态时 ,土层出现非饱和状态和负孔隙水压力 ,产生较大的基质吸力。工程施工中 ,可利用这一特性 ,但必须控制各种向下净流量 ,以抑制土体饱和度增大的趋势。

Xiashu loess deposits are widely distributed on various geomorphic elements at different height, such as hilltop, terrace, foothill and basin etc. It is composed of both loess and red loam, with significantly different composition and structure, especially their stable water content. So we can consider the Xiashu loess deposits to be inhomogeneous. When they are located above the ground water table or in opening state these soils are unsaturated and a negative pore water pressure may appear. Then matrix suction could also be developed. But any downward net flux must be controlled in order to constrain the increasing tendency of saturation when soil behavior is used in construction practice.