饱和砂土中吸力式沉箱抗拉承载特性研究

发布时间：2018-03-22 05:01

本文选题：吸力式沉箱　切入点：离心试验　出处：《大连理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：能源是现代化进程的基础和支柱,现代化脚步日益加快的今天,人们对能源也越来越依赖,然而陆地上蕴藏能源逐渐较少,开发成本也越来越高,因此人们开始将视线投放到能源丰富的近海区域。吸力式沉箱基础是较为常见的近海结构物的基础形式之一,因其具有施工安装费用相对较低、运输和安装相对较为方便、能够重复使用、对场地勘察要求低以及施工时间短等优点,逐步得到了广泛应用,其相关的科学问题已成为近20年的研究热点之一论文主要针对饱和密砂地基中吸力式沉箱基础的抗拉承载特性开展离心模型实验,并归纳变化规律。本文首先介绍了离心模型实验的优缺点和适用范围,随后详细描述了吸力式沉箱抗拉承载力的离心模型实验过程,并较全面论述了实验中所使用仪器设备的精度和稳定性；通过对实验结果的分析,重点讨论了荷载作用位置、荷载作用角度以及砂土相对密实度对沉箱抗拉承载力的影响,给出了斜拉荷载作用下沉箱转动中心位置的所在范围,讨论了沉箱承载性能随外荷载的作用角度和位置变动的发展规律,给出了斜拉荷载作用下沉箱箱顶的位移全过程,最终提出了指定工况条件下的最优荷载作用位置和角度。结合荷载-时间曲线讨论了沉箱抗竖向拉承载力的组成,提出了斜拉荷载作用下沉箱抗拉承载力的三个阶段,论述了三个阶段的沉箱的受力特点,建议了沉箱抗拉控制承载力的选取依据。整个离心模型实验过程包括地基土砂样的制备、砂土地基的饱和、1g条件下沉箱模型的贯入、传感器的布置等步骤。考虑到实验过程中装配操作和仪器测量所引起的实验误差在所难免,文中详细分析了实验中存在的误差,同时提出了控制误差的方法。
[Abstract]:Energy is the foundation and pillar of the modernization process. Today, with the acceleration of modernization, people are more and more dependent on energy. However, there is less energy in the land, and the development cost is higher and higher. The suction caisson foundation is one of the most common foundation forms of offshore structures, because of its relatively low cost of construction and installation, it is relatively convenient to transport and install. The advantages of being reusable, low requirement for site investigation and short construction time have gradually been widely used, and the related scientific problems have become one of the research hotspots in the past 20 years. In this paper, the centrifugal model experiment is carried out in accordance with the tensile bearing characteristics of suction caisson foundation in saturated dense sand foundation, and the variation law is summarized. Firstly, the advantages and disadvantages of centrifugal model experiment and its application range are introduced in this paper. Then, the centrifugal model experiment process of suction caisson's tensile capacity is described in detail, and the precision and stability of the instruments and equipments used in the experiment are discussed comprehensively, and the position of load action is discussed emphatically through the analysis of the experimental results. The influence of load angle and the relative density of sand on the tensile bearing capacity of caisson is given. The range of the center of caisson rotation under the action of cable-stayed load is given. This paper discusses the development law of caisson's bearing capacity changing with the action angle and position of external load, and gives the whole process of caisson roof displacement under the action of cable-stayed load. Finally, the optimal load position and angle under specified working conditions are put forward. The composition of vertical tensile capacity of caisson is discussed in combination with load-time curve, and the three stages of tensile bearing capacity of caisson under cable-stayed load are put forward. The stress characteristics of the caisson in three stages are discussed, and the selection basis of the bearing capacity of the caisson under tension control is suggested. The whole process of centrifugal model experiment includes the preparation of sand sample of foundation soil, the penetration of caisson model under saturated 1 g of sand foundation. Considering that the experiment error caused by assembly operation and instrument measurement is unavoidable, the errors in the experiment are analyzed in detail, and the method of controlling the error is put forward.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U655.544

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