【作者】 曹发辉；

【导师】 李乔；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2004， 硕士

【摘要】 随着大跨径斜拉桥的发展，施工控制在斜拉桥的悬臂施工中起着越来越举足轻重的作用，但温度却日益成为影响施工控制精度的一个重要因素，且常常延误工期而影响施工的进度。本文结合宜宾中坝金沙江大桥的施工控制，首先从混凝土结构的热传导理论出发，简要介绍了预应力混凝土桥梁日照温度场的计算方法，按照第三类边界条件利用四边形等参数单元建立了斜拉桥的主梁和索塔的平面不稳定温度场的有限元分析模型，应用大型有限元软件ANSYS的瞬态热分析功能模拟了主梁和索塔温度场在全天内的变化规律，分析了边肋式主梁的竖向温度梯度规律，并利用ANSYS热—应力耦合功能来求解温度所引起的应力。然后讨论了在施工控制中温度效应的简化计算方法，按照斜拉桥自适应控制的思路，采用现代控制论中的最小二乘法对斜拉桥的主梁、索塔和拉索温差公式中的参数在实测资料的基础上进行了识别，计算了一些关键工况下温度所引起的变形和应力，以说明温度所起的不容忽视的作用。同时对施工控制中考虑温差影响的立模高程的修正这一重要问题进行了探讨；然后对斜拉桥各构件之间的温差在不同的施工阶段下的影响规律进行了研究，为寻找合理的标高、索力测量时间提供了科学依据。更多还原

【Abstract】 Along with the development of long-span cable-stayed bridges, the construction control plays an increasingly significant role on the cantilever construction of cable-stayed bridge. However, temperature becomes an increasingly important factor that affects the accuracy of construction control, and delay time limit for a project as well, thereby affects schedule of the construction. Combined with the construction control of Yibin Zhongba Jinshajiang River Bridge, this thesis firstly presents briefly the calculation method of prestressed concrete bridges’ temperature field caused by sunshine, based on theories of concrete structures’ heat conduction, builds up two-dimensional unstable temperature field’s finite element analysis models of cable-stayed bridge’s girder and tower, according to the third of boundary conditions by using quadrilateral isoparametric element, simulates laws that girder and tower’s temperature fields vary in the whole day, using Transient Thermal Analysis of ANSYS, one large-scale finite element software, analyze the laws of vertical temperature gradient of side-rib girders, and solve stresses caused by temperatures as well, using the thermal-stress coupled-field analysis of ANSYS. Secondly, the simplified calculation method of temperature effects on the construction control is discussed. According to the view of self-adaptive control for cable-statyed bridge, the parameters in thermal difference expressions of the cable-stayed bridge’s girder, tower and inclined cables are identified on the basis of measured data by virtue of the least square method in modern cybernetics, and deformations and stresses which temperatures induce are calculated in some key construction stages as well, for the sake of showing temperature effects which can not be neglected. At the same time, one important issue is discussed home that the revision of elevation of formwork erection when taking into account temperature difference in construction controls, then the temperature laws are studied when every component of cable-stayed bridge are in different temperatures during different construction stages, consequently the scientific bases are provided for proper time for elevation and cable force measurement.更多还原