钢结构斜塔斜拉桥创新设计与结构力学行为  

Innovative Design and Structural Mechanics of Steel Structural Leaning-pylon Cable-stayed Bridge

作　　者：李松 LI Song

机构地区：[1]成都高新未来科技城建设开发有限公司,四川成都610208

出　　处：《城市道桥与防洪》2024年第10期69-75,M0008,M0009,共9页Urban Roads Bridges & Flood Control

摘　　要：斜塔斜拉桥因其造型优美、视觉效果优良等特点常应用于市政桥梁中。以成都天府国际空港新城北部北一线道路工程上的跨绛溪河钢结构斜塔斜拉桥为工程背景,该桥具有桥面较宽、单根背索、桥塔空间异形程度大等特点。基于此,为便于人车通行及结构布置,采用超宽渐变桥面,受超宽渐变桥面影响,所有主次横梁按均不等长设计;桥塔单侧设置1根背索,在塔顶和背索下锚处分散锚固。桥塔为空间异形结构,桥塔采用八边形断面形式,朝主跨的一个面设置凹槽造型,横向整体内倾12°,顺桥向为无规则弧形,为优化桥塔受力,在桥塔顶部节点设置4道桥塔系梁;鉴于该桥结构受力的复杂性,考虑几何非线性,基于有限元软件建立三维空间有限元模型,对最不利荷载下结构力学行为进行分析,分析表明:该桥强度、刚度和拉索疲劳等均满足要求;其中受力最不利点位于背索梁端锚固处,建议对此处进行加强优化设计。The leaning-pylon cable-stayed bridge is often applied in the municipal bridges because of its beautiful design,excellent visual effect and other characteristics.Taking the steel structural leaning-pylon cable-stayed bridge spanning Jiangxi River in North Line I Road Project in the north of Chengdu Tianfu International Airport New Town as the engineering background,this bridge has the characteristics of wide bridge deck,single back cable and special spatial-shaped pylon.Based on this,convenient for the pedestrian and vehicle traffic,and the structural layout,the super-wide gradual-change deck is used.Affected by the super-wide gradual-change deck,all cross beams are designed on the unequal length.One back cable is erected at the single side of the pylon.The anchorage is scattered at the top of the pylon and at the anchor under the back cable.The pylon is a spatial special-shaped structure.The pylon adopts octagonal section form.A groove shape is set towards one face of the main span.The transverse overall is inward tilt 12°,and the irregular arc is along the bridge.In order to improve the stress of the pylon,four pylon collar beams are erected at the node of the pylon top.In view of the stress complexity of the bridge structure,the geometric nonlinearity is considered.Based on the finite element software,a 3D spatial finite element model is established to analyze the structural mechanics under the most unfavorable load.The analysis shows that the strength,rigidity and cable fatigue of the bridge all meet the requirements.And the most unfavorable point of the stress is located at the anchorage of the back cable beam end.It is suggested to strengthen the optimization design of this place.

关 键 词：斜塔斜拉桥 钢箱梁 钢结构 单根背索 创新设计 结构力学行为 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]