考虑土-桥台-上部结构相互作用的曲线桥抗震性能研究

摘要

对国内外历次地震中桥台震害进行了梳理.介绍了简化桥台模型、弹簧桥台模型、弹性梁单元桥台模型等几种针对城市桥梁桥台的典型数值模拟方法;以某立交G匝道曲线梁桥梁为工程背景,建立考虑土-桥台-上部结构相互作用的不同精细化程度的数值模型,开展人工地震动条件下的非线性动力时程反应分析,对比分析不同数值模型的计算误差;在此基础上选取合理数值模型,对桥梁曲率半径进行变参数研究,探讨墩底内力、墩梁相对位移以及台梁相对位移的变化规律.研究发现:提高土-桥台-上部结构相互作用的模拟精细化程度可以更准确地反映桥梁边墩的地震响应,特别是弹性梁单元桥台模型可综合考虑桥台的动力响应,值得推荐;考虑土-桥台-上部结构相互作用条件下,曲率半径越小,各桥墩横向内力及位移差异越明显,建议在进行曲线桥梁抗震设计中应予以重视.%In this paper,several typical numerical simulation methods for urban bridge abutment,such as simplified abutment model,spring abutment model and elastic beam element abutment model,were introduced firstly.Then,the numerical model of different degree of refinement considering the soil-abutment-superstructure interaction was established with the background of an overpass curved bridge.The nonlinear dynamic time-history response analysis under the condition of artificial ground motion was carried out and the calculation errors of different numerical models were compared and analyzed;The variation of bridge internal radius,the internal force of pier bottom,the relative displacement of pier and beam,and the relative displacement of bridge girder were discussed.The results show that the simulation response of the bridge abutment can be more accurately reflected by the improvement of the simulation precision of the soil-abutment-superstructure interactions;especially the elastic beam element abutment model can comprehensively consider the dynamic response of abutment.Considering the soil-abutment-superstructure interactions,the smaller the radius of curvature,the greater the lateral force and displacement of the piers.