考虑翼板承托构造的箱梁剪力滞效应分析方法  

A Theoretical Analysis Method of Shear-lag Effect of Box Girder With Corner Supports

作　　者：郭增伟 李龙景 张俊波 GUO Zengwei;LI Longjing;ZHANG Junbo(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074

出　　处：《北京工业大学学报》2020年第3期253-259,共7页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(51878106,51478072);重庆市自然科学基金资助项目(cstc2019jcyj-msxmx0818);重庆市教育委员会科学技术研究资助项目(KJZD-201900705)。

摘　　要：为解决传统比拟杆法无法求解翼板变厚度箱梁的剪力滞效应的问题,推导考虑翼板承托构造的箱梁比拟杆模型和计算方法,以简支梁为算例分析比拟杆法在研究有翼板承托构造的箱梁剪力滞效应的适用性,并探讨翼板承托构造对箱梁剪力滞效应的影响.通过分析发现:采用本文提出的加劲杆面积和加劲薄板厚度等效方法可以准确分析带有承托构造的箱梁剪力滞效应;加劲杆数量确实会影响弯曲正应力的计算结果,特别是靠近腹板位置的应力,但影响并不显著;除集中支点反力附近的应力集中区域外,比拟杆法理论解与实体有限元数值解吻合良好;相比翼板等厚度的箱梁,承托的存在可以强化腹板对顶板剪切变形的约束,顶板内部水平剪力流随之减小,承托构造在一定程度上可以降低顶板的剪力滞效应.To analyze the shear-lag effect of box girder with varied flange depth by bar simulation method,a modified bar simulation model was proposed to consider the effect of corner supports in this paper.A simply supported box-girder beam was taken as an example to discuss the applicability of the modified method in analyzing the shear-lag effect of box girder with corner supports.It is found that the proposed equivalent method of bar area and plane depth is appropriate to be applied in analyzing the shear-lag effect of box girder,and the calculation results of normal stress on a flange near the web are affected by the number of equivalent bars,which is not significant.The theoretical solution of bar simulation method shows good agreement with the numerical solution by using solid finite element method in most regions,except for the region near bearing supports.Comparing the box-girder with uniform flange depth,the corner supports help the web restrict the shear deformation of flange and decreases the shear stress in flange,which weakens the shear-lag effects of box girder.

关 键 词：桥梁 箱梁 剪力滞效应 比拟杆法 有限元 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]