阜新市东外环预应力混凝土箱梁桥温度效应研究

发布时间：2018-07-03 05:00

本文选题：混凝土箱梁 + 温度场　；参考：《辽宁工程技术大学》2015年硕士论文

【摘要】：预应力混凝土连续梁桥具有行车平顺舒适、伸缩缝少、结构刚度大、变形小、抗震性能好等特点,是当今使用最广泛的桥梁。温度效应对于桥梁施工和设计都存在一定影响,各国规范中虽然进行了相关规定,但对箱梁温度梯度的描述具有较大的差别。考虑箱梁温度场及温度效应与工程实际情况和外界环境等因素有关,温度作用对预应力混凝土箱梁桥施工期间的应力分布和结构变形有很大影响,需针对这一问题进行研究。结合振弦式应变计和锚索测力计的测试原理,通过对阜新市东外环跨铁路预应力混凝土桥工程的现场试验研究,将混凝土水化热、太阳辐射、环境温度等因素考虑在内,对桥梁支点截面和边跨跨中截面不同测点的温度变化规律以及温度应力变化规律进行了分析,同时分析了温度对于桥梁变形程度的影响。将试验测得的温度数据进行了温度梯度曲线拟合,利用MIDAS/Civil建立有限元模型,计算了桥梁0号块的水化热温度变化、截面应力分布和桥梁变形值,并与现场实测值进行对比,对比结果表明：水化热变化规律基本吻合,但未出现梯度下降趋势；顶板和底板的温度应力与实测值的差值控制在0.6MPa之内,但腹板温度应力与实测值差值达到2.4MPa；跨中变形值两者基本一致,支点位置变形值相差1mm。根据计算值和实测值之间的差异对温度梯度模型进行了修正,最后运用修正后的温度梯度模型计算了实际工程中的温度应力,与监测结果对比验证了模型的可靠性,为类似桥梁温度作用下箱梁受力分析和施工控制积累了资料。
[Abstract]:Prestressed concrete continuous beam bridge is the most widely used bridge nowadays because of its advantages of smooth driving, less expansion joints, large stiffness, small deformation and good seismic performance. The temperature effect has a certain influence on the bridge construction and design. Although the relevant regulations are carried out in the national codes, the description of the temperature gradient of the box girder is quite different. Considering that the temperature field and temperature effect of box girder are related to the actual conditions of the project and the external environment, the temperature effect has a great influence on the stress distribution and structural deformation of prestressed concrete box girder bridge during construction, so it is necessary to study this problem. Combined with the testing principle of vibrating string strain gauge and anchor cable dynamometer, through the field test research on the prestressed concrete bridge project of east outer ring span railway in Fuxin city, the hydration heat of concrete, solar radiation, environmental temperature and other factors are taken into account. The variation law of temperature and temperature stress at different measuring points of bridge fulcrum section and side span middle section are analyzed, and the influence of temperature on bridge deformation is also analyzed. The temperature data obtained from the experiment were fitted with the temperature gradient curve, and the finite element model was established by Midas / Civil. The variation of hydration heat temperature, the stress distribution of the section and the deformation value of the bridge were calculated and compared with the measured values in the field. The results show that the variation of hydration heat is basically consistent, but there is no downward trend of gradient, the difference between the temperature stress of roof and bottom plate and the measured value is controlled within 0.6 MPA, but the difference between the temperature stress of web plate and the measured value is 2.4 MPA. The deformation value of span center is basically the same, and the deformation value of fulcrum position is 1 mm. The temperature gradient model is modified according to the difference between the calculated value and the measured value. Finally, the temperature stress in practical engineering is calculated by using the modified temperature gradient model, and the reliability of the model is verified by comparing with the monitoring results. The data are accumulated for the stress analysis and construction control of box girder under the action of similar bridge temperature.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

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