【作者】 张立明；

【导师】 徐贺文；

【作者基本信息】 北京工业大学 ， 桥梁与隧道工程， 2004， 硕士

【摘要】 本文以三跨变截面箱梁弯连续刚构桥为研究对象，分别采用平面有限元和空间有限元两种方法计算了自重作用下控制截面的剪力滞系数，并对剪力滞效应进行了分析。文中分析了弯曲半径、宽跨比、粱高比、墩高、施工阶段、截面位置等参数对变截面箱梁剪力滞效应的影响。 研究结果表明： (1) 空间有限元模型能够较准确地反映出箱形梁桥实际结构截面的受力情况，箱形梁的剪力滞效应不容忽视； (2) 对于半径大于250米的弯桥，用平面杆系分析方法进行设计计算时，对于剪力滞效应的影响，可乘上安全系数1.1～1.2； (3) 弯桥剪力滞效应严重地受到弯曲半径、宽跨比、梁高比、施工阶段及截面位置的影响，而墩高变化对剪力滞效应的影响不大； (4) 半径的改变对截面平均正应力改变不大，但是弯曲半径却改变了截面上的应力分布情况，半径越小，该截面上的最大应力值越大。更多还原

【Abstract】 Based on theoretical analysis and finite element method analysis with the three span continues rigid frame bridges, the paper investigates the shear lag effect of box girder bridges with different cross sections. It concerns on calculating the shear lag coefficient of curve bridges with long span and high pier, through the plan member analyse and space solid analyse,the paper gets some useful conclusions which are different from the straight bridges under plain concrete dead load status. The paper studies the influence effect of the curve bridges with different curve radius, different ratio of width to span, different ratio of beam depth, different height of pier, different construction phase and the different cross section. The main conclusions are as follows:1 The space solid analyse can accurately reflect the stress of real structure of bridges, the curve bridge’s shear lag effect of box girder can’t be substituted by straight bridges and the shear lag effect can not be neglected.2 To the bridges with the radius larger than 250 meters, when the computing method is the plan member analyse the true stress of the structure may be 1.1-1.25 times to the calculated result.3 The shear lag effect of curve bridge is influenced by the curves radius, ratio of width to span, the girder depth, the construction phase and the different cross section position severely, but the influence of height of high pier is not large at all.4 The average normal stress of cross section is not changed much with the different curve radius, but the stress distribution of cross section is changed by the radius of curvature.The less the radius is the larger of the maximum stress is.更多还原