摘要
秭归长江公路大桥为主跨519 m的中承式桁架拱桥。针对该桥设计基准风速高、三峡库区多震的建设条件,以及大跨单拱拱桥拱上立柱高度差别大、桥面梁从肋间穿过的结构特点,以全桥纵、横向静、动力性能及稳定性综合最优为目标开展拱梁约束体系设计。采用MIDAS Civil建立全桥有限元模型,分析墩梁固结布置、肋间弹性约束刚度对结构静力响应、整体稳定性的影响规律,确定采用纵向P1~P3立柱墩梁固结、2号肋间弹性约束刚度取值4000 kN/m、横桥向一侧活动一侧固定的约束体系最优。在该约束体系的基础上,对比分析采用拉索减震支座前、后的地震响应,通过参数分析确定拉索自由行程、拉索刚度取值分别为5 cm、5×104 kN/m时最优,此时E2作用下拱梁间横向最大位移较采用普通盆式支座时下降47%。
The Zigui Changjiang River Highway Bridge is a half-through truss arch bridge with a main span of 519 m.The construction of the bridge faces the challenges of high design reference wind speed and the earthquake-sensitive Three Gorges Reservoir area.In the long-span arch bridge with a single arch ring,the height difference among spandrel columns is big and the deck usually goes through the arch ring,thus the design of the arch-girder restraint system for the Zigui Changjiang River Highway Bridge takes reaching the optimum state of static and dynamic performance and stability of the overall bridge in both the transverse and longitudinal directions as the target.The software MIDAS Civil is used to establish the finite element model of the overall bridge to analyze the influence of the pier-girder fixed connection and the elastic restraint rigidity among ribs on the static response and the global stability of the structure.According to the results of the analysis,the columns of P1~P3 can be fixed with the girder,the elastic restraint rigidity among the No.2 arch ring section draws the value of 4000 kN/m,and the restraint system that is free on one side and fixed on the other side along the bridge width is considered the optimal option.Based on the restraint system,the seismic responses of the bridge before and after the installation of the cable vibration mitigation bearings are compared,the free movement and the horizontal rigidity of the cable are 5 cm and 5×104 kN/m,respectively,which are considered the optimal values,and under such circumstances,the maximum transverse displacement between the arch and the girder is decreased by 47%under the action of E2 earthquake,when compared with the adoption of conventional pot bearings.
作者
杨灿
张铭
YANG Can;ZHANG Ming(Hubei Provincial Communications Planning and Design Institute Co.,Ltd.,Wuhan 430051,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2019年第6期90-95,共6页
Bridge Construction
关键词
桁架拱桥
中承式
拱梁约束体系
部分墩梁固结
弹性约束刚度
拉索减震
truss arch bridge
half-through
arch-girder restraint system
partial fix connection between pier and girder
elastic restraint system
cable vibration damping
作者简介
杨灿,1985-,男,高级工程师,2005年毕业于湖南大学土木工程专业,工学学士,2010年毕业于西南交通大学桥梁工程专业,工学硕士。研究方向:大跨度桥梁工程设计,E-mail:283268542@qq.com;张铭,1973-,男,教授级高工,1996年毕业于长沙交通学院桥梁工程专业,工学学士。研究方向:大跨度桥梁工程设计、科研,E-mail:940277305@qq.com。
