大跨度悬索桥地震响应的几何非线性影响研究  

Study of Geometric Nonlinearity Influences of Seismic Responses of Long Span Suspension Bridge

作　　者：代希华 李保木[2] 苏成[2,3] 陈太聪[2,3] 鲜荣 

机构地区：[1]广东省公路建设有限公司,广东广州510600 [2]华南理工大学土木与交通学院,广东广州510640 [3]华南理工大学亚热带建筑科学国家重点实验室,广东广州510640

出　　处：《桥梁建设》2017年第3期36-40,共5页Bridge Construction

基　　金：国家自然科学基金项目(51678252);亚热带建筑科学国家重点实验室项目(2013ZA01;2015ZC19)~~

摘　　要：为在大跨度悬索桥抗震分析中高效地评估几何非线性效应的影响,以虎门二桥坭洲水道桥(主跨1 688m的双塔钢箱梁悬索桥)为背景,提出一种简化计算方法,研究缆索应力刚化效应和结构大位移效应。首先考虑恒载状态下的几何非线性效应,采用ANSYS建立全桥成桥状态下的基准结构模型,继而建立3种动力模型,考察地震工况下不同几何非线性效应的新增影响,对比2种地震工况下的主梁跨中位移及塔底弯矩。结果表明,3种模型的主梁跨中位移及塔底弯矩结果接近,说明成桥后的大跨度悬索桥由恒载效应引起的几何非线性效应显著,而由地震作用引起的几何非线性效应并不显著。因此,可在成桥状态基准结构模型的基础上,直接开展后续地震响应分析而不必考虑地震作用引起的附加几何非线性影响,可有效提高大跨度悬索桥抗震分析的效率。To efficiently assess the influences of the geometric nonlinearity effects in the seis-mic analysis of long span suspension bridge, the Nizhou Waterway Bridge （a double-tower steel box girder suspension bridge with the main span of 1 688 m） of the Second Humen Bridge was taken as an example, a simplified calculation method was put forward and with the method, the in-fluences arising from the cable stress stiffening effect and the structure large displacement effect were studied. The geometric nonlinearity effects of the bridge in the dead load state were firstly considered and the ANSYS was used to establish the reference structure model for the whole bridge of the bridge in the completion state. 3 different dynamic models were then established to observe the new influences arising from the different geometric nonlinearity effects and the mids-pan displacement of the main girder and the bending moment of the tower footings under the 2 seis-mic load cases were compared. The results suggest that the midspan displacement of the main gird-er and the bending moment of the tower footings of the 3 models are close, showing that the geo-metric nonlinearity effects of the completed long span suspension bridge caused by the dead load effect are significant while the nonlinearity effects caused by the seismic action are not. In suchcase,the follow-up seismic response analysis can be directly carried out, using the reference struc-ture model of the completed bridge, not needing to consider the additional geometric nonlinearity influences caused by the seismic action and the efficiency of the seismic analysis of the long span suspension bridge can be thus effectively improved.

关 键 词：大跨度悬索桥 地震响应 有限元法 动力模型 成桥状态 几何非线性 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]