三跨斜交简支梁桥动力计算模型简化方法研究  

Simplified method of dynamic calculation model for a 3-span simply supported skewed girder bridge

作　　者：湛敏 王军文[1,2] 闫聚考 

机构地区：[1]石家庄铁道大学土木工程学院,石家庄050043 [2]石家庄铁道大学道路与铁道工程安全保障省部共建教育部重点实验室,石家庄050043 [3]石家庄铁道大学大型结构健康诊断与控制研究所,石家庄050043

出　　处：《振动与冲击》2017年第17期231-237,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(51508347);河北省自然科学基金项目(E2015210038);河北省大型基础设施防灾减灾协同创新中心项目(HB2011011);河北省重点学科建设项目(桥梁与隧道工程)的项目(XK1700702)

摘　　要：以一座斜交角为45°的3×30 m简支梁桥为工程背景,借助Open Sees软件建立单梁模型和多梁模型,在忽略碰撞效应、仅考虑伸缩缝处纵向碰撞效应、同时考虑伸缩缝处纵向碰撞与抗震挡块处横向碰撞效应三种情况下,分析地震引起的桥面峰值转角及纵向最大位移的变化规律,并通过与精细化板单元模型计算结果的对比研究两种模型的计算精度。结果表明:忽略碰撞作用时,多梁模型和单梁模型均能合理反映三跨斜交简支梁桥实际的地震反应;考虑碰撞作用时,多梁模型的计算精度普遍高于单梁模型;通过改进单梁模型主梁节点质量的分布方式,可提高计算结果的精度,平均可提高8.7%。A simplified single beam model and a multi-beam model for a 3-span girder bridge with the skew angle of 45° were established with the software Open Sees. The bridge deck＇s peak rotation angle and the maximum longitudinal displacement caused by earthquake were analyzed in 3 cases including ignoring pounding effect, only considering longitudinal pounding effect between decks at expansion joints,and considering both longitudinal pounding effect at expansion joints and transverse pounding effect at aseismic blocks. Comparing the calculation results using two simplified models with those using a model of refined plate elements,the two simplified models＇ computing accuracies were studied.The results showed that both the simplified single beam model and the multi-beam model can reasonably reflect the actual seismic responses of the bridge when ignoring seismic pounding effect; when considering seismic pounding effect,the calculation accuracy of the multi-beam model is generally higher than that of the single beam one; the calculation accuracy of the single beam model can be improved by about 8. 7% through modifying this model ＇s main beam node mass distribution.

关 键 词：斜交桥 简支梁桥 简化模型 地震响应 地震碰撞 

分 类 号：U448.41[建筑科学—桥梁与隧道工程] U442.55[交通运输工程—道路与铁道工程]