斜腹板薄壁箱梁横向内力的改进分析方法  

An Improved Method for Analyzing Transverse Internal Forces of Thin-walled Box Girders with Inclined Webs

作　　者：王晨光[1] 张元海[1] 汪洋生 WANG Chenguang;ZHANG Yuanhai;WANG Yangsheng(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：《铁道学报》2021年第9期127-132,共6页Journal of the China Railway Society

基　　金：国家自然科学基金(51968040);兰州交通大学青年基金(2019024)。

摘　　要：为更准确地计算箱形梁在偏心荷载作用下的横向内力,在推广的框架分析法基础上,建立了满足平衡条件的新计算模型。以畸变位移与框架位移的协调关系为基础,推导出计算箱形梁横向内力的基本公式。通过简支箱形梁的数值算例,详细分析两种不同方法对箱形梁横向内力的影响。结果表明:推广的框架分析法只在计算直腹板箱形梁横向内力时是准确的;采用新模型计算所得的横向内力与有限元数值模拟结果的分布规律一致,尤其在底板上取得了更高精度;箱形梁横截面上的横向弯矩随底、顶板宽度之比的增大而逐渐增大,随高宽比的增大而逐渐减小。因此,适量减小斜腹板箱梁的底板宽度或增加梁高可以减小横向内力,缓解因横向应力过大产生的纵向裂缝。In order to calculate the transverse internal force of box girder under eccentric load more accurately,a new calculation model satisfying the equilibrium condition was established on the basis of the extended frame analysis method.Based on the coordination relationship between the distortion displacement of box girder and the displacement of frame,the basic formulas for calculating the transverse internal force of box girder were derived.The effects of two different calculation methods on the transverse internal force of box girders were analyzed by numerical examples of simply supported box beams.The results show that the extended frame analysis method is accurate only when calculating the transverse internal force of straight-web box girder.The transverse internal force calculated by the new model is consistent with the distribution law of the finite element numerical simulation results,especially on the bottom plate.The transverse bending moment on the cross section of the box girder gradually increases with the increase of the width ratio of the bottom and the top plate,and is gradually reduced with the increase of the depth-width ratio.Therefore,decreasing the width of the bottom plate or increasing the height of the box girder can reduce the transverse internal force and alleviate the longitudinal cracks caused by the excessive transverse stress.

关 键 词：桥梁工程 箱形梁 框架分析 横向内力 畸变位移 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]