沉管隧道火灾温度场作用下管节结构三维力学分析

发布时间：2018-03-06 15:40

  本文选题：沉管隧道　切入点：火灾　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：港珠澳大桥工程是我国首座涉“两岸三地”的世界超级工程，主体工程包括一座跨越伶仃洋航道的海底沉管隧道，是目前世界上最长（5664m）、埋深最深（50m）、规模最大（双向六车道）、单节管节最重（75000T）的海底沉管隧道，也是我国交通建设史上技术最复杂、标准最高的海中隧道工程，设计施工难度在世界范围内首屈一指。 港珠澳海底沉管隧道位于水下海床基槽上，结构横向为两孔一管廊单层衬砌，纵向为管节+复合接头的串联式复合体，这些特殊的外部条件与内部构造形式对运营中出现的火灾更为敏感。一旦发生火灾，管节结构与接头均会发生损伤，破坏时难以修复，对结构防水与安全健康服役影响巨大。基于此，本文依托港珠澳大桥工程，针对沉管隧道火灾场景设计、管节结构三维温度场、管节结构与接头高温应力及损伤等方面展开研究，具体内容如下： ①港珠澳沉管隧道火灾场景 基于沉管隧道的断面特点，通过1:1足尺寸火灾实验及其数据分析，在参考公路隧道火灾场景的基础上，建立了随时间、空间变化的港珠澳海底沉管隧道的完整火灾场景。 ②沉管隧道管节结构温度场分布规律 通过建立火灾温度场三维数值模型，，考虑了不同温度级别（600℃、900℃、1200℃）以及RABT等四种火灾曲线情况，得到了沉管隧道结构内部的温度传播与分布规律。探讨了玻镁防火板对于管节结构的隔热效果，研究结果表明半断面布设防火板的方案能够满足耐火要求。 ③高温作用下管节结构力学行为 在考虑管节（段）之间的接触关系的基础上，通过建立有（无）隔热条件下沉管隧道三维热力耦合模型，得到了两种条件下管节与节段的位移、应力分布规律及损伤深度，并且针对管节接头的几何特点，找到了最大损伤深度位置的规律。 ④高温作用下接头力学行为 通过建立有（无）隔热条件下沉管隧道管节、节段接头分析模型，包括管节接头GINA止水带及两种接头处的传力剪力键，得到了不同升温曲线下管节接头的变形及两种接头的剪力变化规律，并通过计算论证指出了着火侧内墙及顶板位置剪力键受火灾高温影响较大。
[Abstract]:The Hong Kong-Zhuhai-Macao Bridge project is the first world superproject involving "the two sides of the strait and three places" in China. The main project includes a submersible tunnel across the Lingdingyang waterway. At present, it is the longest undersea tunnel in the world, with the deepest depth of 50m, and the largest scale (two-way six-lane tunnel, single pipe section with the heaviest weight of 75000T). It is also the most technologically complex and standard tunnel project in the history of transportation construction in China. The difficulty of design and construction is second to none in the world. Hong Kong-Zhuhai-Macao undersea sinking tunnel is located on the foundation of underwater seabed. The structure of the tunnel is a series compound with two holes and a pipe corridor single layer lining and a pipe joint in the longitudinal direction. These special external conditions and internal structures are more sensitive to fires in operation. In the event of fire, both the pipe structure and the joints are damaged, which is difficult to repair. Based on the waterproofing and safe and healthy service of the structure, this paper, based on the HongKong-Zhuhai-Macao Bridge project, aims at the fire scene design of the immersed tunnel and the three-dimensional temperature field of the pipe segment structure. The high temperature stress and damage of pipe joints and joints are studied. The details are as follows:. 1 Fire scene of Hong Kong Zhuhai-Macau immersed Tunnel. Based on the cross section characteristics of immersed tube tunnel, based on the 1: 1 full-size fire experiment and its data analysis, and referring to the fire scene of highway tunnel, the complete fire scene of Hong Kong-Zhuhai-Macao undersea immersed tunnel with time and space variation is established. Temperature field distribution law of pipe joint structure in 2-submersible tunnel. By establishing a three dimensional numerical model of fire temperature field, four kinds of fire curves, such as 600 鈩

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