铁路空心高墩温度场及温度效应研究

发布时间：2018-03-14 17:08

  本文选题：混凝土空心桥墩　切入点：日照温度场　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：混凝土空心桥梁结构如果裸露于大自然环境中，将会长期经受着各种复杂的环境条件变化的影响，从而使结构产生随时间变化的非线性温度荷载并产生温度效应。这种非线性的温度荷载在某些情况下产生的温度效应可能要比其他荷载产生的效应还要大，非线性的温度荷载使得混凝土空心桥梁结构开裂破损，从而严重影响结构的使用安全。因此，要控制桥梁结构的安全，研究分析混凝土空心桥梁结构的温度荷载及效应是十分必要的。 本论文主要以“山区高速铁路桥梁混凝土高墩结构设计技术研究”重点科研项目为依托，以建设中的贵广线幸福源水库特大桥为工程背景，选取了该桥的12#桥墩为研究对象，针对混凝土空心箱型截面桥墩的日照和寒潮温度场与温度效应进行了系统的分析研究。主要研究工作和结论如下： 本论文主要采用现场实测、数值模拟、数值计算和理论分析相结合的研究方法。通过回归分析现场实测数据拟合提出适合广西桂林片区的空心桥墩日照和寒潮温度梯度模式；采用大型有限元软件ANSYS建立桥墩有限元模型，数值模拟计算空心桥墩温度场；对比分析现场实测数据与模拟数据，调整计算参数，通过模拟的数值计算桥墩的温度效应。 通过实测分析温度场沿桥墩墩高方向的变化是均匀的，所以可以把三维温度场当成二维平面温度场来计算；对幸福源水库大桥12#桥墩的日照和寒潮温度场进行了不间断观测，运用最小二乘法拟合提出了适合广西桂林片区混凝土铁路桥墩的日照和寒潮温度梯度模式；采用ANSYS软件按第三类边界条件来模拟计算混凝土箱型截面桥墩日照温度场和温度效应是准确可靠的，最大压应力达到5.99MPa，最大拉应力达到2.24MPa，，墩顶最大位移达到6.081mm；采用ANSYS软件按第一类边界条件来模拟计算混凝土箱型截面桥墩寒潮温度场是准确可靠的，最大拉应力为4.66MPa，已经超过了C40级混凝土的抗拉强度；通过对不同寒潮降温值下桥墩寒潮温度效应的有限元分析可知,当寒潮降温使得桥墩内外壁温差为5℃时，桥墩外壁拉应力相应增大2.0MPa左右；内壁压应力在顺桥向方向增幅为1.1M Pa/5℃;内壁压应力在横桥向方向增幅为0.3MPa/5℃。
[Abstract]:If the concrete hollow bridge structure is exposed to the natural environment, it will endure the influence of various complex environmental conditions for a long time. So that the structure produces a nonlinear temperature load over time and a temperature effect, which, in some cases, may have a greater temperature effect than others. Nonlinear temperature load makes the concrete hollow bridge structure crack and damage, which seriously affects the safety of the use of the structure. Therefore, it is necessary to control the safety of the bridge structure. It is necessary to study and analyze the temperature load and effect of concrete hollow bridge structure. In this paper, based on the key scientific research project of "study on the structural Design of concrete High Pier structure of High-speed Railway Bridge in mountainous area", taking the large bridge of Xinyuan Reservoir in Guiguang Line as the engineering background, the 12# pier of the bridge is chosen as the research object. The temperature field and temperature effect of sunshine and cold wave of concrete hollow box section pier are studied systematically. The main work and conclusions are as follows:. This paper mainly adopts the research methods of field measurement, numerical simulation, numerical calculation and theoretical analysis. Through regression analysis, the paper puts forward the sunshine model of hollow bridge pier and the cold wave temperature gradient model suitable for Guangxi Guilin region. The finite element model of bridge pier is established by using the large-scale finite element software ANSYS, and the temperature field of hollow pier is numerically simulated, and the field measured data and simulation data are compared and analyzed, and the calculated parameters are adjusted, and the temperature effect of the pier is calculated by numerical simulation. The variation of temperature field along the high direction of pier is uniform, so the three-dimensional temperature field can be calculated as two-dimensional plane temperature field, and the sunshine and cold wave temperature field of 12# bridge pier of Xingyuan Reservoir Bridge are observed continuously. Using least square fitting, the sunshine and cold wave temperature gradient model of concrete bridge piers in Guilin region of Guangxi are put forward. It is accurate and reliable to simulate and calculate the sunshine temperature field and temperature effect of concrete box section pier by using ANSYS software according to the third kind of boundary condition. The maximum compressive stress is 5.99 MPA, the maximum tensile stress is 2.24 MPA, the maximum displacement of the pier top is 6.081mm. It is accurate and reliable to use ANSYS software to simulate and calculate the cold wave temperature field of concrete box section bridge pier according to the first type boundary condition. The maximum tensile stress is 4.66 MPA, which has exceeded the tensile strength of C40 grade concrete. Through the finite element analysis of the cold wave temperature effect of bridge pier under different cold wave cooling values, it can be seen that when the cold wave cooling makes the temperature difference between the inner and outer wall of the bridge pier to be 5 鈩

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