考虑畸变效应的钢桁腹-混凝土组合箱梁横向内力计算方法  

Calculation Method of Transverse Internal Force of Concrete Composite Box Girder with Steel Truss Webs Considering Distortion Effect

作　　者：套格套 丁南宏[1] 冀伟[1] 刘奇 TAO Getao;DING Nanhong;JI Wei;LIU Qi(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,兰州730070

出　　处：《建筑钢结构进展》2025年第2期1-8,20,共9页Progress in Steel Building Structures

基　　金：国家自然科学基金(51708269)。

摘　　要：为合理分析偏心荷载作用下钢桁腹-混凝土组合箱梁的横向内力,对钢桁腹杆进行等效处理,参考框架分析法的基本原理,建立了考虑畸变效应的钢桁腹-混凝土组合箱梁横向内力计算公式。结合该类组合箱梁的结构特点和受力特性,提出了新的翘曲应力分布模式,并推导得到新应力分布模式下的畸变翘曲系数计算公式。通过将公式解与有限元解进行对比,发现二者吻合良好,计算误差均在10%以内,尤其在底板位置处精度更高,验证了推导公式的正确性和新应力分布模式的合理性。此分析方法可反映出箱梁畸变和横向框架作用对该类组合箱梁横向内力的影响。对荷载偏心距、高跨比和悬臂板宽度进行参数分析,结果表明:随着荷载偏心距的增加,该类组合箱梁角点处的横向弯矩变化规律与混凝土箱梁的规律不同,主要是由于钢桁腹杆对顶底板的约束程度降低;该类组合箱梁的横向弯矩随着高跨比的增加而增加,增长规律呈曲线分布;选择合适的悬臂板宽度可有效降低钢桁腹-混凝土组合箱梁的横向弯矩。In order to reasonably analyze the transverse internal forces of concrete composite box girder with steel truss webs under eccentric load,an equivalent treatment of steel truss webs was carried out,and a calculation formula of the transverse internal force of concrete composite box girder with steel truss webs was established by referring to the basic principle of frame analysis.According to the structural and mechanical characteristics of this kind of composite box girder,a new warping stress distribution model was proposed,and the calculation formula of warping coefficient of distortion under the new stress distribution model was obtained.By comparing the proposed solution with the finite element solution,it was found that the two solutions were in good agreement,with calculation errors all below 10%,especially at the position of the bottom plate,validating the correctness of the derived formula and the rationality of the new stress distribution model.This analysis method can reflect the influence of warping and transverse frame action on the transverse internal forces of the composite box girder.The parameters of load eccentricity,height-to-span ratio and cantilever plate width were analyzed.The results show that with the increase of load eccentricity,the transverse bending moment at corner point of the composite box girder is different from that of the concrete box girder,which is mainly due to the decrease of the constraint degree of the steel bar on the top and bottom plate.The transverse bending moment of this kind of composite box girder increases with the increase of height-to-span ratio,and the growth law shows a curve distribution.The transverse bending moment of concrete composite box girder with steel truss webs can be effectively reduced by selecting the appropriate cantilever plate width.

关 键 词：钢桁腹-混凝土组合箱梁 横向内力 翘曲应力 框架分析法 畸变效应 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]