【作者】 李鑫；

【导师】 田仲初；

【作者基本信息】 长沙理工大学 ， 桥梁与隧道工程， 2009， 硕士

【摘要】 混凝土双索面Π型梁斜拉桥受力影响因素较多，但是其对温度荷载较为敏感，温度效应直接影响到施工过程的安全性及使用阶段的可靠性。因此研究混凝土Π型梁斜拉桥的温度场及其温度效应对于完善其施工和设计具有重要意义。本文以江西鄱阳湖大桥为工程背景，基于施工过程中测试的大量温度数据对混凝土Π型梁斜拉桥的斜拉索及无铺装层Π型梁的温度场进行研究，完成的主要工作有：( 1 )基于鄱阳湖大桥现场测试的温度数据进行了回归分析，得出Π型截面梁顶板及梁肋在水化热、太阳辐射、降温以及不同季节下的温度场变化规律。对比分析了斜拉索、大气、梁肋的温度变化规律，对斜拉索与大气温差以及及斜拉索与梁肋温差进行了分析，得出斜拉索与大气温在±3℃以内。在施工阶段斜拉索与梁肋平均温度差值多在±5℃以内。( 2 )通过A N S Y S有限元软件建立混凝土Π型梁的温度场数值模型，按照桥区处的边界条件，对温度场进行了仿真计算，与实测数据进行分析比较，并最终拟合出Π型梁的竖向温度梯度。( 3 )采用M I D A S有限元软件建立鄱阳湖大桥有限元模型，通过成桥状态下的模态测试结果对该模型中的主梁弹性模量和容重进行了修正，在此基础上对其在主跨合龙前后状态下的温度效应进行分析，得出温度效应在施工阶段远大于在成桥阶段、系统温差、索塔温度梯度对结构影响较小、主梁截面温度梯度对结构影响较大、索梁温差对结构影响最大。( 4 )基于现场测试的大量水化热温度数据，对比研究了鄱阳湖大桥梁肋与承台大体积混凝土的水化热发展规律，同时对影响水化热温度的重要因素进行了敏感性分析。最后结合现场的温控过程对大体积混凝土的温控措施进行分析，得出文中提出的温控措施具有较好实用性。更多还原

【Abstract】 There are numerous factors to influence the force received by concrete double-cable-planesπ-type-girder cable-stayed bridge, but the temperature load is one of the most sensitive factors. Temperature effect directly impacts on the safety of the construction process and the reliability of the stage of use. Therefore, the research of temperature gradient and effect ofπ-type-girder cable-stayed bridge has great significance to improving the construction and design.Taking Poyang Lake Bridge in Jiang Xi province as the engineering background, this thesis will study the temperature field of concrete cable-stayed bridgeπtype girder during constructed stage with the amount of temperature test data obtained in the engineering construction by the supervisors. Which provide the reference for establishing related norms of the bridge. In this thesis, the mian tasks finished are as follows:(1)On the basis of the regression analysis of on-site-test temperature data, the variation law ofπ-type-girder under different circumstances is obtained. Comparative analysis of the cable-stayed, the atmosphere, the temperature of beam rib variation of temperature and atmospheric, as well as cable-stayed cable-stayed with the beam and rib analyzed temperature, and atmospheric temperature reached smaller cable-stayed, in the±3℃or less. During the construction phase of cable-stayed beam rib and the average temperature difference more than±5℃.(2)Using finite element program(ANSYS) , simulation calculation analysis is carried out to study the temperature gradient ofπ-type-girder with the boundary conditions of the real bridge. Compared with the on-site-test data, finally a fitting of the vertical temperature gradient is obtained.(3)With the Software of MIDAS, it will be built to the whole bridge three-dimensional finite element model, and then be amended. On the basis of these, this thesis will analyze the temperature effect of Poyang Lake Bridge in order to obtain the construction phase of the temperature effect is much larger than in the completed status of the bridge, system temperature, temperature gradient on the tower structure was less affected, the main beam temperature gradient influence on the structure, demand structure of beam temperature on the most affected.(4)This thesis will make a numerical analysis of the bridge’s hydration heat of mass concrete to form a numerical model, and then verify the accuracy of numerical model through a large number of on-site testing hydration heat of the temperature data. With the sensitivity analysis of the factors of impacting hydration heat, it is to draw the general selection principles of construction related parameters of mass concrete . At last, Combining the on-site process of temperature control, Come to the text of the control measures put forward practical good.更多还原