大跨度预应力混凝土连续刚构桥时域抖振分析  

Buffeting Analysis in Time Domain for Long Span Prestressed Concrete Continuous Rigid Frame Bridge

作　　者：李飞 刘多特[2] LI Fei;LIU Duote(CCCC Infrastructure Maintenance Group Co.Ltd.,Beijing 100011,China;School of Civil Engineering, Southwest Jiaotong University,Chengdu Sichuan 610031,China)

机构地区：[1]中交基础设施养护集团有限公司,北京100011 [2]西南交通大学土木工程学院,四川成都610031

出　　处：《铁道建筑》2018年第3期5-9,共5页Railway Engineering

摘　　要：为研究大跨度预应力混凝土连续刚构桥在不同施工阶段结构体系转变下的风致抖振气动性能,采用计算流体动力学的近壁面低雷诺数SST k-ω湍流模型,求解主梁与桥墩各关键断面的静风绕流气动力参数。通过谐波合成法模拟来流10 min下的主梁及桥墩节点脉动风速时程样本,并利用Scanlan准定常气动力模型,对在施工最大双悬臂、最大单悬臂及成桥合龙状态时主梁的风致抖振位移响应进行了计算。研究结果表明:主梁风致响应的主导外因随施工体系的转变而改变,结构体系的完善(整体刚度的增大)使得抖振气动效应逐渐减弱;最大双悬臂状态时,梁端节点横桥向抖振位移达到极大值5 cm,可能对施工监控产生干扰;主梁各节点转角位移相对于线位移受到的影响可忽略不计。In order to study the wind-induced buffeting aerodynamic performance of long span prestressed concrete continuous rigid frame bridge under different construction stages,a low Reynolds number of near wall turbulence model of SST k-ωwas used to calculate the static wind f low around aerodynamic parameters of typical sections of main girder and piers by computational f luid dynamics method.The method of weighted amplitude wave superposition was used to simulate the pulsating wind speed time history samples of main girder and pier joints under the inf low wind of ten minutes.The displacement responses of main girder induced by buffeting effects at the states of the largest double cantilevers,the largest single cantilever and bridge closure were calculated based on Scanlan s quasi-steady aerodynamic model.The results show that the leading factors of wind-induced responses of main girder are altered with the changes of construction system,the buffeting aerodynamic effects will be gradually reduced with the improvement of construction system(the increase of bridge integral stiffness).In the case of the largest double cantilevers state,the lateral buffeting displacement of the girder end joint reaches a maximum value of 5 cm,which may interfere with the construction monitoring.The inf luence of the angular displacement of main girder on the linear displacement can be neglected.

关 键 词：铁路桥梁 时域抖振 湍流模型 数值计算 连续刚构桥 施工状态 合龙状态 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]