顶承式筒型基础内部土体施工预压联合电渗加固固结试验及理论研究

The soil properties inside and around the bucket foundation, which would be changed by the construction methods, greatly influence the bearing capacity models for the foundation. It was found out in the model tests that the soil inside the bucket would be strengthening by suction if the ratio of diameter to height of the foundation is big enough, as well as the soil plug inside the bucket would disappear, too. According to the observed phenomenon of the soil strengthening and the electric osmosis method in the muddy clay, there are two key problems to be studied that are ①research on the consolidation mechanism caused by cover preloading-suction pressure- electric osmosis method and optimizing the related factors; and ② cover-bearing model and settlement estimation in long-term service time. Moreover, another working content is establishing the design method of the quick soil reinforcement technique and the estimation model for the settlement of the bucket foundation in long-term service time. The research will solve the problem of construction and settlement due to design ideas, which will broaden the engineering application range of bucket foundations.

筒型基础结构内部和外侧土体的性质对筒型基础承载力和承载力模式产生重要的影响；筒型基础的设计形式的不同，在沉放过程中会对筒型基础内部的土体特性产生不同的影响，通过模型试验发现，当筒型基础的直径和高度的比值足够大时，沉放末期筒型基础内部的土体会受到筒顶的挤压而变得更加密实，沉放过程中的土塞效应也随之消失。本项目针对这种沉放挤密效应，结合电渗方法对筒内土体（淤泥质粘土）进行加固，围绕两个核心问题展开研究：（1）筒顶预压-筒内土体负压-联合电渗的复杂状态下软基加固固结机理及控制参数优化；（2）长期服役状态下筒型基础筒顶承载模式及长期沉降评估理论，进而建立筒型基础内部土体快速加固设计方法和新型基础长期使用中沉降预测模型和计算方法，解决目前由于筒型基础设计方法原因造成的下沉困难或沉降问题，拓宽筒型基础的工程应用范围。

筒型基础作为一种新型海上风电基础，受到越来越多的关注。本项目围绕筒顶预压-筒内土体负压-联合电渗的复杂状态下软基加固固结机理及控制参数优化和长期服役状态下筒型基础筒顶承载模式及长期沉降评估理论两个主要问题开展研究，通过筒顶承载模式结构解决筒型基础下沉困难和后期沉降问题，形成了筒型基础内部土体快速加固方法，并成功应用于海上风电复合筒型基础样机工程。已发表22篇论文，其中SCI检索13篇，EI检索8篇，培养博士后1名，硕士/博士研究生7 人，参加了4次国际会议，申请并授权国家发明专利5项。