洞庭湖生态经济区区域性软土空间区划及典型工程特征

Regional Soft Soil Spatial Division and Typical Engineering Characteristics of Dongting Lake Ecological and Economic Zone

该文在总结前人对洞庭湖晚更新世以来洞庭湖的演变特征及地层年代划分的基础上,结合洞庭湖生态经济区若干个公路项目建设的软土研究成果,对该区域软土进行了空间区划及典型特征对比分析。研究认为,洞庭湖生态经济区区域性软土由三种软土组成,君山软土、安乡软土为晚全新世的长江、湘江为主河漫滩相沉积、中全新世中期末以来的深湖相沉积,砂纹淤泥质土是以早全新世的古河槽河漫滩相沉积;君山软土分布在以长江、湘江为主的湖区河网河漫滩,安乡软土分布在除君山软土外的洞庭湖腹地,砂纹淤泥质土分布在古河槽河漫滩;三种软土的工程地质特性分类为君山软土最好,砂纹淤泥质土次之,安乡软土最差。该文研究结论可作为本区域的发展提供有利的地质基础支撑。

Based on the summary of previous studies on the evolutionary characteristics and stratigraphic age division of Dongting Lake since the Late Pleistocene,this paper combines the soft soil research results of several highway projects in the Dongting Lake Ecological and Economic Zone to conduct a spatial zoning and a comparative analysis of typical characteristics of soft soil in the area.Research suggests that the regional soft soil in the Dongting Lake Ecological and Economic Zone is composed of three types of soft soil,Junshan soft soil and Anxiang soft soil,which are deposited in the flood plain of the Yangtze River and Xiangjiang River in the Late Holocene,the deep lake deposits since the end of the Middle Holocene,and the muddy soil with sandy laminae,which is deposited in the ancient river channel flood plain deposits in the Early Holocene.Junshan soft soil is distributed in the river network and flood plain of the lake area mainly composed of the Yangtze and Xiangjiang Rivers,the Anxiang soft soil is distributed in the hinterland of Dongting Lake,and the muddy soil with sandy laminae is distributed in the ancient river channel and flood plain.The engineering geological characteristics of the three types of soft soil are classified as Junshan soft soil is the best,followed by muddy soil with sandy laminae,and Anxiang soft soil is the worst.The research conclusion of this paper can provide favorable geological foundation support for the development of this region.