超宽圆端形薄壁空心墩温度效应分析
发布时间：2018-08-31 15:09
【摘要】：随着我国铁路近十年的高速化建设，在山区以及地表高差悬殊的地区修建的铁路桥梁也屡见不鲜。由于桥梁跨度的增加而采用大跨的结构形式，其经济指标以及建设难度也随之成倍增长。有时，出于对经济和技术的考虑，大跨度桥梁的结构形式不一定是最合理的选择，在某些场合条件下，也是不科学的。因此，工程设计人员常采用小跨径，高桥墩的结构形式。而薄壁空心墩由于其自身的许多优点如：自重较小、圬工体积较少、在地震时有较小的惯性力而被广泛采用。 但是研究表明，薄壁空心高墩这种结构形式具有一定的特殊性，其稳定性较差，且受外界环境的影响较大，比如：垂直度、外部温度的突然降低或升高等都会引起内力，而这些因素对桥梁结构安全的影响都不容忽视。 铁路空心桥墩的温度效应问题日益引起工程界的重视，国内外许多学者和研究人员都做过探讨，但仅局限于宽度较小的单线或双线桥墩，对车站内多线超宽空心高墩温度效应的分析和研究几乎空白。文章基于通用分析软件ANSYS，采用三维瞬态热-结构耦合场方法对兰渝铁路兰州枢纽大砂坪特大桥四线空心桥墩在日照升温和寒潮降温作用下温度场、温度应力进行分析。 本文以兰渝线兰州枢纽大砂坪特大桥四线铁路圆端形超宽薄壁空心墩为工程实例，进行如下工作： 1)介绍国内外对温度效应问题进行研究的概况以及背景，以及在进行桥梁设计时对温度效应问题提出的相关设计规定。 2)简要叙述热量传递的方式，以及引起温度效应的过程。 3)由于温度效应在一定的约束条件下必然会引起温度应力，本文将对几种典型的最不利温度荷载工况采用有限元软件ANSYS模拟四线铁路圆端形超宽薄壁空心墩温度场，，并计算其温度应力，同时根据计算结果提出相应的解决方案。 4)总结本文的工作，由于时间和能力的限制提出现有情况下的分析不足，为以后的研究工作提出新的建议。 本文通过对设置纵向隔板和无纵向隔板两种模型计算分析比较，结果表明超宽空心高墩在寒潮作用下环向、竖向温度应力值较大，所以在设计中应引起足够重视,而是否加设纵向隔板对温度应力的影响较小。根据温度应力计算结果，通过设置合理的墩身钢筋，解决铁路多线超宽空心墩由温度应力与外荷载组合作用下，造成的混凝土开裂在规范要求以内。
[Abstract]:With the high-speed construction of railway in our country in recent ten years, railway bridges built in mountainous areas and areas with great difference in surface height are also common. Because of the increase of the span of the bridge, the long span structure is adopted, and its economic index and construction difficulty also increase exponentially. Sometimes, for the sake of economy and technology, the structural form of long-span bridge is not necessarily the most reasonable choice, and under some circumstances, it is also unscientific. Therefore, engineering designers often adopt the structural form of small span and high piers. The thin wall hollow pier is widely used because of its many advantages such as small weight, less masonry volume and small inertial force during earthquake. However, the research shows that the structure form of thin-walled hollow high pier has some particularity, its stability is poor, and it is greatly influenced by external environment, such as: vertical degree, sudden decrease or rise of external temperature will cause internal force, etc. The influence of these factors on bridge structure safety can not be ignored. The temperature effect of railway hollow piers has been paid more and more attention to by many scholars and researchers at home and abroad, but it is limited to single or double track piers with small width. The analysis and study of the temperature effect of the super wide hollow high pier in the station are almost blank. Based on the general analysis software ANSYS, the temperature field and temperature stress of the fourth line hollow pier of Dazhaping super bridge in Lanzhou railway project of Lanyu railway are analyzed by using the three-dimensional transient thermal-structural coupling field method under the action of sunshine and cold wave cooling. This paper takes the round end type ultra-wide thin-walled hollow pier of the fourth line railway of Dashaping Bridge of Lanzhou Railway of Lanyu Line as an engineering example. The following works are carried out: 1) the general situation and background of the research on temperature effect at home and abroad are introduced. As well as the relevant design regulations for temperature effect in bridge design. 2) briefly describing the heat transfer mode. And the process of causing temperature effect. 3) because temperature effect is bound to cause temperature stress under certain constraint conditions, In this paper, the finite element software ANSYS is used to simulate the temperature field of the four-line railway circular end-shaped ultra-wide thin-walled hollow pier under several typical most unfavorable temperature loading conditions, and the temperature stress is calculated. At the same time, according to the results of the calculation, the corresponding solutions are put forward. 4) the work of this paper is summarized. Due to the limitation of time and ability, the analysis of the existing situation is insufficient, and some new suggestions are put forward for the future research work. In this paper, through the calculation and comparison of the two models with and without longitudinal diaphragm, the results show that the vertical temperature stress of the super-wide hollow high pier under the action of cold tide is large, so it should be paid enough attention to in the design. The effect of longitudinal partition on the temperature stress is small. According to the calculation results of temperature stress, the concrete cracking caused by the combination of temperature stress and external load can be solved by setting reasonable steel bar of pier body, and the cracking of concrete caused by the combination of temperature stress and external load can be solved within the requirement of code.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.5
本文编号：2215364
[Abstract]:With the high-speed construction of railway in our country in recent ten years, railway bridges built in mountainous areas and areas with great difference in surface height are also common. Because of the increase of the span of the bridge, the long span structure is adopted, and its economic index and construction difficulty also increase exponentially. Sometimes, for the sake of economy and technology, the structural form of long-span bridge is not necessarily the most reasonable choice, and under some circumstances, it is also unscientific. Therefore, engineering designers often adopt the structural form of small span and high piers. The thin wall hollow pier is widely used because of its many advantages such as small weight, less masonry volume and small inertial force during earthquake. However, the research shows that the structure form of thin-walled hollow high pier has some particularity, its stability is poor, and it is greatly influenced by external environment, such as: vertical degree, sudden decrease or rise of external temperature will cause internal force, etc. The influence of these factors on bridge structure safety can not be ignored. The temperature effect of railway hollow piers has been paid more and more attention to by many scholars and researchers at home and abroad, but it is limited to single or double track piers with small width. The analysis and study of the temperature effect of the super wide hollow high pier in the station are almost blank. Based on the general analysis software ANSYS, the temperature field and temperature stress of the fourth line hollow pier of Dazhaping super bridge in Lanzhou railway project of Lanyu railway are analyzed by using the three-dimensional transient thermal-structural coupling field method under the action of sunshine and cold wave cooling. This paper takes the round end type ultra-wide thin-walled hollow pier of the fourth line railway of Dashaping Bridge of Lanzhou Railway of Lanyu Line as an engineering example. The following works are carried out: 1) the general situation and background of the research on temperature effect at home and abroad are introduced. As well as the relevant design regulations for temperature effect in bridge design. 2) briefly describing the heat transfer mode. And the process of causing temperature effect. 3) because temperature effect is bound to cause temperature stress under certain constraint conditions, In this paper, the finite element software ANSYS is used to simulate the temperature field of the four-line railway circular end-shaped ultra-wide thin-walled hollow pier under several typical most unfavorable temperature loading conditions, and the temperature stress is calculated. At the same time, according to the results of the calculation, the corresponding solutions are put forward. 4) the work of this paper is summarized. Due to the limitation of time and ability, the analysis of the existing situation is insufficient, and some new suggestions are put forward for the future research work. In this paper, through the calculation and comparison of the two models with and without longitudinal diaphragm, the results show that the vertical temperature stress of the super-wide hollow high pier under the action of cold tide is large, so it should be paid enough attention to in the design. The effect of longitudinal partition on the temperature stress is small. According to the calculation results of temperature stress, the concrete cracking caused by the combination of temperature stress and external load can be solved by setting reasonable steel bar of pier body, and the cracking of concrete caused by the combination of temperature stress and external load can be solved within the requirement of code.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.5
【参考文献】
相关期刊论文 前2条
1 简方梁;吴定俊;;高墩日照温差效应耦合场分析[J];结构工程师;2009年01期
2 余f雄;柔性墩温度场场形及影响因素的分析[J];江汉大学学报;1998年06期
本文编号：2215364
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