摘要
为显著改善高烈度震区H形混凝土桥塔的抗震性能,以8度震区包银铁路主跨260 m斜拉桥为例,采用Midas Civil软件建立全桥动力分析模型,分别对采用混凝土横梁、钢横梁、波形钢腹板横梁和直钢腹板横梁四种横梁构造形式的桥塔进行抗震分析及技术经济比选。研究表明:相比混凝土横梁方案,钢横梁和钢腹板组合横梁方案在横向地震下桥塔塔柱响应弯矩降幅16.8%~20.7%,横梁响应内力降幅23.9%~52.2%,但纵向地震下桥塔响应内力变幅较小;钢横梁和钢腹板组合横梁方案用钢量增加,但改善了结构受力,塔柱配筋率大幅减少,造价均低于混凝土横梁方案,其中钢腹板组合横梁方案造价最低,考虑到波形钢腹板相对直钢腹板具有更好的抗剪屈曲性能,最终推荐采用波形钢腹板组合梁的横梁构造方案;遵循“弱化响应,强化抗力”的设计理念对混凝土桥塔波形钢腹板组合横梁地震作用下的内力响应规律和构造设计进行研究,为高烈度震区斜拉桥桥塔抗震设计提供一种新思路。
To significantly improve the seismic performance of H-shaped concrete bridge tower in meizoseismal region,the cable-stayed bridge with 260-meter main span of Baotou-Yinchuan Railway located in an 8-degree high-intensity seismic region is taken as an example.The spatial finite element model for the bridge is established with Midas Civil,and four schemes of tower crossbeam including concrete crossbeam,steel crossbeam,crossbeam with corrugated steel webs and flat steel webs are analyzed and compared technically and economically.Results show that:compared with concrete crossbeam,the bending moment of the bridge tower column will be reduced by 16.8%~20.7% and the internal force of the crossbeam will be decreased by 23.9%~52.2% under the action of lateral earthquake when the tower adopts steel crossbeam or crossbeam with corrugated or flat steel webs.However,the schemes of tower crossbeam have little influence on the internal force of bridge tower under the action of longitudinal earthquake.Compared with concrete crossbeam,the steel quantity of other crossbeams is higher but with lover cost,because the steel and composite crossbeam can improve the stress state and the reinforcement quantity is reduced substantially.The crossbeam with corrugated steel webs is recommended because of its lowest cost of all and better shear buckling behavior than crossbeam with flat steel webs.Following the design concept of“weakening response and strengthening resistance”,the internal force response law under the action of earthquake and structural design of composite crossbeam with corrugated steel web in concrete tower are studied,which provides a new idea for the seismic design of cable-stayed bridge tower in meizoseismal region.
作者
牟兆祥
MU Zhaoxiang(China Railway Design Corporation,Tianjin 300308,China)
出处
《铁道标准设计》
北大核心
2023年第4期73-79,85,共8页
Railway Standard Design
基金
中国铁路设计集团有限公司科技开发课题(7218126)。
关键词
铁路桥
斜拉桥
高震区
桥塔横梁
弯矩曲率分析
抗剪计算
波形钢腹板
railway bridge
cable-stayed bridge
meizoseismal region
tower crossbeam
moment-curvature analysis
shear calculation
corrugated steel web
