变截面连续箱梁活荷载内力增大系数计算  

The internal force increment coefficient of the continuous box girder of variable cross-sections subjected to live load

作　　者：王赞芝[1] 辛立凤[1] 吴辉琴[1] 王家全[1] 李卫 高大峰[3] 

机构地区：[1]广西工学院土木建筑工程系,广西柳州545006 [2]陕西省文化遗产保护规划设计研究院,陕西西安710075 [3]西安建筑科技大学土木工程学院,陕西西安710055

出　　处：《广西大学学报（自然科学版）》2011年第1期113-120,共8页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(51009030);广西教育厅科研资助项目(201012MS122);广西工学院博士基金科研项目(院科博0901);广西工学院大学生科研立项重点项目(2010052;2010053)

摘　　要：为研究变截面连续箱梁在非对称荷载作用下的受力特性,将连续梁的各支座当作铰支,采用差分方法计算变截面连续梁各跨的抗弯惯矩修正系数;将连续梁的每跨两端当成固定端,计算变截面连续箱梁桥的抗扭惯矩修正系数;沿梁宽将桥分为8等分,画出9个梁位的影响线,按照可能布置的车道数分别布载,最终计算出各车道数对应的内力增大系数,并考虑按现行规范进行横向折减。研究结果指出,将箱梁当作一个整体,可以有效地考虑其强大的抗扭能力,计算方法更科学合理,计算结果更准确可靠,反映了箱梁工作的实际情况。In order to study the properties of the continuous box girder of variable cross-section subjected to unsymmetrical loads,all supports of the continuous bridge are regarded as pins,and the finite difference method was used to calculate the correction factors of flexural stiffness for every span of the continuous bridge.Then,regarding the two ends of every span of the bridge as clamped,the correction factors of torsional stiffness were calculated.After that,the bridge was divided into eight equal parts along the width direction,and thus a total of nine locations were specified.For each location,an influence line was drawn.Charging the influence lines with loads on possible lanes so as to calculate the internal force increment coefficient of each lane with the lateral reduction considered according to the Chinese code.Results show that this approach considers the box girder section as a whole with closed sections and large torsional rigidity,which reflects the actual performance of the box girder and is more reasonable theoretically.The result also verifies the precision of this approach.

关 键 词：内力增大系数 变截面梁 连续箱梁桥 有限差分法 抗弯惯矩修正系数 抗扭惯矩修正系数 等代简支梁法 Guyon-Massonnet法 

分 类 号：U448.14[建筑科学—桥梁与隧道工程]