混凝土系杆拱连续梁温度梯度及其效应研究

发布时间：2018-09-01 13:49

【摘要】：桥梁是指跨越天然或人工障碍而修建的建筑物,随着科学技术的发展,越来越多组合体系结构在现代桥型中得到应用。系杆拱连续梁做为结合了梁桥与拱桥各自优点的桥型,在受力方面的优点得以充分发挥,呈现出优良、稳定的经济指标和美观的外型。虽然梁拱组合体系桥梁具有诸多优点,但对于其桥型的研究和探讨并不完善,许多问题正在被中外学者所研究发现。温度效应,做为近年来越来越受到广泛关注的问题,自上世纪六十年代就有学者对其进行研究,温度所产生的应力有时甚至可以与外荷载相当,温度作用会直接影响桥梁的安全性。为验证温度对系杆拱连续梁的影响,本论文以实际工程为背景,对混凝土系杆拱连续梁桥进行现场温度试验。在系杆及吊杆周围布置温度测点,对测点进行连续7d的温度测量,观测内容包括系杆竖向及横向测点的温度变化规律和吊杆周围的温度变化规律,并通过对系杆温度的观察,利用半经验半理论公式对系杆竖向及横向的温度梯度进行拟合,最终根据已求出的温度梯度曲线,将非线性温度梯度等效为线性温度梯度,以温度荷载的形式施加在全桥MIDAS有限元模型中,以研究温度对系杆拱连续梁的影响。本论文首先详细阐述了桥梁结构温度场的分析理论和计算方法；温度作用的分类及其对桥梁结构的影响；并介绍温度效应的计算理论及各国规范关于温度梯度的规定。然后通过对现场实测温度数据分析,得出系杆及吊杆的温度分布规律;并选用指数函数对系杆竖向和横向的最不利温度分布进行拟合,确定系杆的温度梯度曲线。最后利用该桥有限元模型在竖向温度梯度、横向温度梯度及其组合的作用下,通过对控制截面的内力和应力的分析,发现由温度梯度产生的温度应力、温度变形都不容忽视；并将竖向温度梯度与规范规定的温度梯度进行了温度效应的比较,发现在拟合出的温度梯度效应下,系杆控制截面的应力小于规范温度梯度效应下的数值。
[Abstract]:Bridges refer to buildings built across natural or man-made obstacles. With the development of science and technology, more and more composite structures have been applied in modern bridge types. Although the beam-arch composite system bridge has many advantages, its research and discussion are not perfect. Many problems are being found by scholars at home and abroad. Temperature effect, as a problem which has attracted more and more attention in recent years, has been studied by scholars since the 1960s. In order to verify the influence of temperature on tied-arch continuous girder, the field temperature test of concrete tied-arch continuous girder bridge is carried out under the background of practical engineering. The temperature measurement points are arranged around tied-arch and suspender to connect the measured points. The temperature measurement for the next 7 days includes the temperature variation law of the vertical and transverse measuring points of the tie bar and the temperature variation law around the hanger bar. Through the observation of the tie bar temperature, the vertical and transverse temperature gradients of the tie bar are fitted by semi-empirical and semi-theoretical formulas, and the nonlinear temperature is finally fitted according to the obtained temperature gradient curve. Degree gradient is equivalent to linear temperature gradient, which is applied to the MIDAS finite element model of the whole bridge to study the effect of temperature on the tied arch continuous beam. The calculation theory of effect and the stipulation of temperature gradient in the codes of other countries are given. Then the temperature distribution law of tie rod and hanger rod is obtained by analyzing the measured temperature data in situ. The exponential function is used to fit the most disadvantageous temperature distribution of tie rod vertically and horizontally, and the temperature gradient curve of tie rod is determined. Under the action of vertical temperature gradient, transverse temperature gradient and their combination, through the analysis of the internal force and stress of the control section, it is found that the temperature stress and deformation caused by the temperature gradient can not be ignored; and the temperature effect of the vertical temperature gradient is compared with the temperature gradient stipulated in the code, and it is found that the temperature is fitted out. Under the gradient effect, the stress of the control section of the tie bar is less than that of the normal temperature gradient effect.
【学位授予单位】：东北林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

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