Study On The Quaternary Sedimentary Environment And Soft Soil Properties In Jiangsu Coastal Area

In this paper, the Quaternary sediments in the coastal area of Jiangsu Province are treated as the research object. Sorting and analysising the regional geological survey data of the survey areas in Nantong, Yancheng and Lianyungang. Combined with quaternary borehole data and geotechnical test data, the paper studies and analyzes the characteristics of the Quaternary sedimentary environment evolution and its influence on the physical and mechanical properties of Quaternary soft soil.Based on the geographical position, topography and characteristics of the Quaternary sediments and the division plan of the predecessors, the Quaternary strata of Jiangsu coastal area are divided into three parts: the Yangtze River Delta region, Huaihe basin region and Yishuguan river basin region. According to the change of major elements and trace elements in strata with depth and using the geochemical element analysis method, the Quaternary strata of Nantong test area are divided into 9 belts. The paper describes the characteristics of Quaternary climate and sedimentary environment evolution and analysises the correlation between the constant elements, Results show: Elements Si and Ti, element Al and Fe, Ti and element P and Mg, Ti has a strong correlation in the content. Just when the content is more than or less than a certain value, the other elements will show a strong correlation or transformation of positive and negative correlation.From the angle of Quaternary soft soil sedimentary environment, the paper analysises the variation law of physical and mechanical properties of soft soil. Results show: The soft soil in Lianyungang area is Littoral Facies Sedimentary, its porosity, water content and compressibility are increasing from land to sea and the trend of the change of density is the opposite. The soft soil in Yancheng area is Lagoon facies Sedimentary, its porosity, water content and compressibility are increasing from the center to the boundary and the trend of the change of density is the opposite. The soft soil in Nantong area is Shallow sea facies Sedimentary and due to the complexity of the sedimentary environment, the change of the physical and mechanical properties of soft soil is not regular.