考虑材料劣化条件下近海地区大跨悬索桥抗震能力分析  

Seismic Capacity Analysis of Long Span Suspension Bridges with Material Degradation

作　　者：张庆开 武芳文[3] ZHANG Qingkai;WU Fangwen(China Design Group Co.,Ltd.,Nanjing,Jiangsu 210001,China;Jiangsu Huatong Engineering Technology Co.,Ltd.,Nanjing,Jiangsu 210001,China;School of Highway,Chang′an University,Xi′an,Shaanxi 710000,China)

机构地区：[1]华设设计集团股份有限公司,江苏南京210001 [2]江苏华通工程技术有限公司,江苏南京210001 [3]长安大学公路学院,陕西西安710000

出　　处：《水利与建筑工程学报》2025年第2期67-73,共7页Journal of Water Resources and Architectural Engineering

基　　金：国家自然科学基金(52378121)。

摘　　要：为研究近海地区混凝土劣化效应对大跨径桥梁结构抗震能力的影响,以某座大跨径悬索桥为依托,基于非线性时程分析方法,对结构进行地震增量动力分析(IDA)以计算其抗震性能。在考虑全寿命服役周期内氯离子对主筋与箍筋屈服强度、有效截面积等因素的影响下,得到主塔在考虑材料劣化效应下控制截面弯矩-曲率曲线,并通过混凝土本构关系模型确定其损伤指标下,然后建立悬索桥SAP2000有限元模型,利用12条不同地震波对结构进行IDA分析,通过对各服役年限下计算数据的处理分析,确定控制截面的损伤曲线,进而得到不同年限下主塔截面的材料劣化程度与结构抗震性能的关系。计算结果表明:塔底截面服役50年、75年、100年时,在地震荷载作用下完全损伤概率的增幅分别达到14.5%、22.0%、35.5%。表明材料劣化因素对结构承载力及抗震性能的影响比较严重,建议在桥梁设计中应充分考虑外界环境的不利因素,以保证桥梁结构的抗震性能。In order to analyze the influence of concrete degradation effect on the seismic resistance of long-span bridge structures in coastal areas,seismic incremental dynamic analysis(IDA)is conducted on a long-span suspension bridge to calculate its seismic performance based on nonlinear time history analysis method.During the entire service life,considering the influence of chloride ions on the yield strength and effective cross-sectional area of the main reinforcement and stirrups,the bending moment curvature curve of the control section of the cable tower structure is obtained under the consideration of material degradation effects,and its damage index is determined through a concrete constitutive relationship model.Through a finite element model of SAP2000 suspension bridge,and IDA analysis was conducted on the structure using 12 different seismic waves.By analyzing data under different service years,the damage curve of the control section is derived,and the relationship between the material degradation degree of the main tower section and the seismic performance of the structure under different service years is obtained.The calculation results show that when the bottom section of the cable tower is in service for 50 years,75 years,and 100 years,the probability of complete damage under seismic loads increases by 14.5%,22.0%and 35.5%.This indicates that material degradation facors have a significant impact on the structural bearing capacity and seismic performance.It is recommended that adverse external envirommental factors be fully considered in bridge design to ensure the seismic performance of bridge structures.

关 键 词：大跨径悬索桥 材料劣化 钢筋锈蚀 增量动力分析 地震损伤 

分 类 号：TU442[建筑科学—岩土工程]