大型全容式LNG储罐桩的优化设计研究

发布时间：2018-05-24 16:19

本文选题：LNG储罐 + 桩　；参考：《天津大学》2014年硕士论文

【摘要】：随着清洁能源在世界范围内得到重视,LNG(Liquefied Natural Gas)的需求量与日俱增。LNG储罐是LNG接收站的核心,目前最常见的类型为高桩承台基础的预应力混凝土全容式储罐。国内目前已建或在建的大型LNG储罐均由国外公司主要设计、建造。LNG储罐的基础在项目总造价中占很大的比重,是影响结构是否安全的重要部位。探究如何能更好地进行大型全容式LNG储罐优化设计,对于提升我国自主设计、建造能力,推动LNG储罐向超大型化发展,以及促进我国国民经济的发展具有重大的战略意义和经济意义。本课题主要参考国内外关于LNG储罐及桩的相关规范,并借助ANSYS有限元分析软件,对LNG储罐桩的优化设计进行研究。本文的主要研究内容及结论如下:1.参考不同国家的相关规范,总结其对LNG储罐桩的相关要求,并对桩刚度的计算方法进行比较。根据中国规范和日本规范分别计算桩的静刚度和动刚度,得出桩刚度动力放大系数的变化规律。2.对比ANSYS中关于桩的不同模拟方法,证明本文所选的方法与试桩试验结果较接近,满足分析精度的要求。3.建立16万m3LNG储罐的整体壳单元模型,探究在不同单一荷载作用下,不同桩刚度的LNG储罐的上部结构的反应情况。结果表明:在单一荷载作用下,当结构以竖向变形为主时,内力大小主要受桩的竖向刚度大小的影响;在风荷载、温度作用、有效预应力作用下,结构内力大小同时受桩的竖向刚度与水平刚度的影响。4.建立16万m3LNG储罐1/4实体单元模型,考虑自重及附件重、长期有效预应力、正常操作气压、静液压作用、均布活荷载,通过变化桩距(桩径、桩数)、桩长、截面形状、环桩圈数、刚度分布、布置形状等参数,比较桩和底板的位移和应力变化情况。基于所得到的规律,提出桩的优化设计方案,并验证该方案大部分适用于超大容积的LNG储罐,但由于桩体最大应力的位置发生变化,关于截面形状的结论不适用。
[Abstract]:With the increasing demand for clean energy in the world, the Natural storage tank is the core of the LNG receiving station. At present, the most common type is the prestressed concrete full-capacity storage tank with high pile cap foundation. At present, large scale LNG storage tanks have been built or are under construction in China, which are mainly designed by foreign companies. The foundation of constructed .LNG tanks accounts for a large proportion of the total cost of the project, and is an important part of the safety of the structure. To explore how to better carry out the optimization design of large full-capacity LNG storage tank, to promote the independent design and construction ability of our country, and to promote the development of LNG storage tank to super large scale. And promote the development of our national economy has great strategic and economic significance. This paper mainly refers to the relevant codes of LNG tanks and piles at home and abroad, and studies the optimization design of LNG tank piles with the help of ANSYS finite element analysis software. The main contents and conclusions of this paper are as follows: 1. Referring to the relevant codes of different countries, this paper summarizes the relevant requirements of LNG tank pile, and compares the calculation methods of pile stiffness. According to Chinese and Japanese codes, the static stiffness and dynamic stiffness of pile are calculated, and the variation rule of dynamic magnification factor of pile stiffness is obtained. Comparing with the different simulation methods of pile in ANSYS, it is proved that the method chosen in this paper is close to the test result of pile test and meets the requirement of analysis precision. The integral shell element model of 160000 m3LNG storage tank was established to investigate the response of the superstructure of LNG tank with different pile stiffness under different single loads. The results show that under a single load, the internal force is mainly affected by the vertical stiffness of the pile when the structure is dominated by vertical deformation, and under the action of wind load, temperature and effective prestress, the internal force is mainly affected by the vertical stiffness of the pile. The internal force of the structure is affected by both the vertical and horizontal stiffness of the pile. The 1 / 4 solid element model of 160000 m3LNG storage tank was established, considering the weight and accessory weight, long-term effective prestress, normal operating pressure, hydrostatic action, uniform distribution of live load, and by changing pile spacing (pile diameter, pile number, pile length, section shape, ring pile circle number). Stiffness distribution, layout shape and other parameters to compare the displacement and stress of pile and floor. Based on the obtained rules, the optimal design scheme of piles is proposed, and it is verified that most of the schemes are suitable for LNG tanks with very large volume. However, due to the change of the position of the maximum stress of the pile, the conclusion on section shape is not applicable.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1;TE972

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