伊拉克美索不达米亚平原软土分布特征及工程性质分析

伊拉克美索不达米亚平原地区分布着厚层状的流塑~软塑状黏性土,主要分布在底格里斯河和幼发拉底河流域,以湖相、沼泽相沉积环境为主。为了查明该区域内软土对拟建"巴士拉-法奥"段铁路路基工程的影响,采取现场调查、地质钻探、原位及室内试验等综合勘探手法,调查研究软土的分布特征及工程性质。研究发现:美索不达米亚平原地区广泛分布的软土具有垂直分布和空间分布特征。在垂直分布上软土的状态受深度控制,一般0~3 m,多呈流塑状,3~15 m呈软塑状,15~25 m呈软塑~硬塑状。且土层盐渍化严重,易溶盐含量从地表往下逐渐减弱,强盐渍土主要分布在地表0~5 m;在空间上具有受地形地貌、降雨量、河流水系、沉积环境等控制的特征。

Soft Soil Distribution and Engineering Property Analysis of Alluvial Plain of Iraq

The alluvial plain of Iraq is distributed with thick layer of silt clay,the soft clay is mainly distributed in the plains of the south,the Tigris and the Euphrates river valley. In order to find out the impact of soft soil on the subgrade of the engineering project,field investigation,geological drilling in situ,laboratory test and electric integrated exploration technique are employed to study the distribution characteristics and engineering properties of soft soil. The study shows that the mesopotamian plain areas are vertically and spatially distributed with soft soil with the depth of 0 ~ 3 m in general,appearing in soft-flow-plastic state,and 15 to 25 m in soft-plastic to hard-plastic state. The content of soluble salt is reduced continuously from the surface down,and the strong saline soil are mainly distributed in the depth of 0 ~ 5 m. The area is dominated spatially by the topography,the rainfall,river water system and sedimentary environment.