基于力法的斜支承连续箱梁挠曲扭转内力分析  

Analysis on flexural-torsional internal force of skewly supported continuous box girder based on force method

作　　者：魏彦红 张元海[1] WEI Yanhong;ZHANG Yuanhai(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《铁道科学与工程学报》2021年第9期2324-2332,共9页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51968040,51468032)。

摘　　要：为研究斜支承连续箱梁的内力分布规律和斜交角变化对内力分布的影响,分别给出均布扭矩荷载和集中扭矩荷载作用下,简支箱梁约束扭转控制微分方程初参数解的简化结果。以简支箱梁为基本结构,斜支点的约束反力为多余未知力,建立多跨斜支承连续箱梁的力法方程。选取斜支承两跨连续箱梁为算例,用本文方法和ANSYS软件计算其在竖向均布荷载作用下的各项内力,并分析斜交角变化对各项内力的影响。研究结果表明:按本文方法计算的弯矩和扭矩与ANSYS计算值吻合良好;在竖向对称均布荷载作用下,弯矩和扭矩沿梁轴对称分布,双力矩反对称分布,各项内力随斜交角的变化具有单调性;在竖向偏心均布荷载作用下,各项内力均不再对称分布,其随斜交角的变化规律也更加复杂。This paper investigated the distribution of internal forces in skewly supported continuous box girder and the influence of variation of skew angle on the distribution of internal forces.Firstly,the simplified results of initial parametric solutions for restrain torsion governing differential equation of simply supported box girder subjected to uniform and concentrated torque load were given respectively.Then with considering the simply supported box girder as the basic structure and the constraint reaction forces on skew supports as redundant unknown forces,the basic equation for force method of multi-span skewly supported continuous box girder was established.A skewly supported two-span continuous box girder was finally adopted as an example and each internal force of it under vertical uniform load was calculated by using the present method and ANSYS software.The influence of variation of skew angle on each internal force was analyzed.The results show that the bending moment and torque calculated by the present method are in good agreement with the results computed by ANSYS.The bending moment and torque are distributed symmetrically along the box-girder axis,but the bi-moment is distributed anti-symmetrically.The variation of each internal force with skew angle is monotonic as the skewly supported two-span continuous box girder subjected to the vertical symmetrical uniform load.The internal forces are no longer distributed symmetrically and the variation of each internal force with skew angle is more complicated as it is subjected to the vertical eccentric uniform load.

关 键 词：连续箱梁 斜支承 弯扭特性 力法 斜交角 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]