广东某近海风电场海床表层土物理力学性质

Physical and Mechanical Properties of Topsoil in an Offshore Wind Farm in Guangdong

基于筒形基础在海上风电工程应用关键技术研究及地基基础设计要求,从广东某近海风机工程场址的20余米水深浅水域采集的柱状样进行分析,探究该区域海床表层土的基本物理力学性质,获取各项参数指标。结果表明:该地区近海表层土类型为黏土或粉质黏土,其物理力学性质在不同站位和不同深度存在明显波动,与其他近海地区的沉积物性质存在明显差异;天然含水率与液塑限较低,孔隙比较小,该表层土持水能力较差;颗粒级配曲线连续,粒度分布差异不大;不同站位土体的直剪强度有一定差别,但均存在沿深度变化的规律性和统一性;采用适用于低强度土的全流动贯入T-bar试验来测定土体原状样和重塑样强度,得出的土体不排水抗剪强度随深度的增加而增大,灵敏度基本位于中灵敏度范围。所得结果不仅为该地区工程建设提供了关键地质勘察设计资料,同时为今后对该海域沉积物力学特性研究及海洋工程建设提供了重要参考。

Based on the key technology research of the application of the cylindrical foundation in offshore wind power engineering projects and the requirements of the foundation design,this paper analyzes the cylindrical samples collected from more than 20 meters deep and shallow water area of an offshore wind turbine project site in Guangdong Province,explores the basic physical and mechanical properties of the seabed surface soil in this area,and obtains the parameters and indexes of the seabed surface soil in this area.The results show that the surface soil is classified as clay or silty clay,and the physical and mechanical properties of the surface soil vary in different stations and depths,which is significantly different from the sediment properties in other offshore areas;the natural water content and AtterbergLimits are low,the void ratio is small,and the water retention capacity of the surface soil in this area is poor;the particle gradation curve of surface soil is continuous and the gradation difference in the surface soil is not significant.The direct shear strength of the soil samples at different stations is different,but there is regularity and unity along the depth.The full flow penetration T-bar test suitable for low strength soil is used to measure the strength of undisturbed and remolded soil samples.The undrained shear strength of soil increases with the increase of depth,and the sensitivity is basically in the middle sensitivity range.Through a series of analysis and research,the physical and mechanical properties of the surface soil on the seabed of the site are obtained,which not only provides the key geological survey and design data for design and construction projects in the area,but also provides an important reference for the future study of the mechanical properties of the sediment in the offshore soils.