港区吹填软土地基特性与工作区影响深度研究

发布时间：2018-02-28 19:31

本文关键词： 港口吹填土现场试验数值模拟回弹模量工作区深度　出处：《华中科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：大量港口建设对土地资源的需求日益迫切，通常采用吹填的方式进行围海造地。港口吹填地基在荷载作用下会产生较大的沉降。因此，控制港口地基工作区深度，防止其产生过大的变形，是围海造陆工程中的重要研究课题。本文通过理论计算、现场试验及数值模拟的方法对吹填港区地基顶面当量回弹模量值与地基的工作区深度进行了系统的研究。根据目前现有的常用地基工作区深度理论计算公式，采用当量厚度法对Boussinesq公式计算结果进行修正并以附加应力与自重应力的比值等于0.1对工作区深度进行定义；计算得出港区不同铺面结构在设计荷载下优化的砂垫层厚度。针对港区软土地基特性，设置现场承载板及压实度试验，发现地基回弹模量随着砂垫层厚度增加而增加，当砂垫层较薄时，地基难以充分压实，地基回弹模量值较离散。通过现场足尺试验对集装箱荷载和拖挂车荷载工况下地基中的应力进行了测试，得出地基中的附加应力值随着荷载的增加而增加，且沿深度分布呈降低趋势的规律，并得出不同铺面在荷载下的地基工作区深度。根据现场试验结果对采用有限差分软件FLAC3D建立的模型进行修正，着重研究了不同铺面结构在相应设计荷载作用下，地基中附加应力、附加应力与自重应力比值、竖向应变和侧向位移等的分布规律，并得出规范荷载作用下不同铺面类型的优化砂垫层厚度表。本文的研究成果可为《港口道路与堆场设计规范》的编制提供一定参考。
[Abstract]:The demand for land resources in a large number of port construction is becoming more and more urgent, and usually the method of reclamation is used to reclaim the land from the sea. Under the action of load, a large settlement will be produced on the foundation of the port. Therefore, the depth of the working area of the port foundation is controlled. The prevention of excessive deformation is an important research subject in land reclamation engineering. In situ test and numerical simulation method, the equivalent modulus of resilience of the top surface of the foundation and the depth of the working area of the foundation are systematically studied. According to the existing theoretical formulas for calculating the depth of the foundation working area, the equivalent thickness method is used to modify the calculation results of the Boussinesq formula and define the depth of the working area with the ratio of additional stress to gravity stress equal to 0.1. The optimum sand cushion thickness of different pavement structures in port area under design load is obtained. In view of the characteristics of soft soil foundation in port area, it is found that the elastic modulus of the foundation increases with the increase of the thickness of sand cushion, and when the sand cushion is thin, the foundation is difficult to be fully compacted. The elastic modulus of the foundation is discrete. The stress in the foundation under the loading condition of container load and towing vehicle is tested through the field full-scale test. It is concluded that the additional stress value in the foundation increases with the increase of the load. The distribution along the depth shows a decreasing trend, and the depth of the subgrade working area under different pavement loads is obtained. According to the field test results, the model established by finite difference software FLAC3D is modified, and the additional stress, the ratio of additional stress to gravity stress in the foundation of different pavement structures under the corresponding design load are studied emphatically. The distribution law of vertical strain and lateral displacement is obtained, and the optimized sand cushion thickness table with different pavement types under the action of code load is obtained. The research results of this paper can provide some reference for the compilation of Port Road and yard Design Code.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U655.54

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