吊杆断裂对系杆拱桥力学性能的影响  

Influence of Suspender Fracture on the Mechanical Properties of Tied Arch Bridges

作　　者：柴文浩 杨雅勋[1] 张宇航 CHAI Wen-hao;YANG Ya-xun;ZHANG Yu-hang(School of Highway,Chang'an University,Xi'an 710064,China)

机构地区：[1]长安大学公路学院,西安市710064

出　　处：《公路》2021年第9期174-179,共6页Highway

基　　金：国家自然科学基金项目,项目编号51878059。

摘　　要：为研究吊杆断裂对系杆拱桥力学性能的影响,以某钢管混凝土系杆拱桥为研究对象。首先建立其有限元模型,采用正装迭代和倒拆相结合的方法计算其成桥索力,后与设计成桥索力相比较,验证了有限元模型的正确性。然后分析了吊杆断裂的数量及断裂位置对主梁线形、剩余吊杆内力及拱肋应力的变化规律。其结果表明,任意吊杆断裂,主梁线形变化值在断裂位置出现下挠峰值,且随着断裂位置往跨中偏移,该峰值不断增大,最大增加了7.18%。吊杆断裂只会引起同侧附近相邻吊杆的内力变化,对其余吊杆内力变化影响不大;其中跨中截面和L/4截面的吊杆对主梁线形和吊杆内力影响较大。双吊杆断裂之后,主梁线形和吊杆内力的变化值可近似认为单吊杆断裂时产生的变化值之和。且吊杆对称断裂时,主梁线形变化值和吊杆内力出现对称分布。吊杆断裂之后,拱肋最大值应力较完好时增加了24.8%。To study the influence of suspender fracture on the mechanical performance of tied arch bridges,a steel pipe and concrete tied arch bridge is used as the research object.The finite element model is established,and a combination of positive iteration and inverted dismantling is used to calculate the bridge cable force,which is later compared with the design cable force to verify the correctness of the finite element model.Then,the change rules of girder geometric shape,suspender internal force,stresses of arch ribs after the suspender fracture of different numbers and different positions are analyzed.The results show that the change of girder geometric shape appears as a peak deflection at the fracture location for any suspender,and the peak increases as the fracture location is shifted towards the centre of the span,with a maximum increase of 7.18%.The suspender fracture only causes the changes of the internal force of the adjacent suspender near the same side,and has minor impact on the changes in the internal forces of the remaining suspender.The suspender located at mid-span section and L/4section have a greater effect on the girder geometric shape and the internal force of suspender.After the fracture of the double suspender,the changes of girder geometric shape and the internal force of the suspender can be approximated as the sum of the changes produce by the fracture of the single suspender.In the case of symmetrical rupture,the values of the changes of girder geometric shape and the internal forces of the suspender appear symmetrically distributed.The maximum stresses in the arch ribs increase by 24.8%after the fracture of the suspender compared to the intact condition.

关 键 词：系杆拱桥 吊杆断裂 主梁线形 吊杆内力 有限元模拟 

分 类 号：U441.5[建筑科学—桥梁与隧道工程] U448.225[交通运输工程—道路与铁道工程]