三塔两跨悬索桥中塔位移及跨中挠度简化计算方法  

A Simplified Calculation Method for Middle Pylon Deformation and Mid-span Deflection in Three-pylon and Two-span Suspension Bridge

作　　者：柴生波[1] 王秀兰[2] 任翔[1] 

机构地区：[1]西安科技大学建筑与土木工程学院,陕西西安710054 [2]长安大学公路学院,陕西西安710061

出　　处：《公路交通科技》2016年第5期85-91,共7页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51408484)

摘　　要：为获得活载作用下三塔两跨悬索桥变形解析公式,首先通过微分与变分方法推导了均布荷载作用下单跨主缆挠度的解析计算公式,通过综合研究塔顶位移及主缆弹性伸长引起的主缆变形,推导了用于计算三塔两跨悬索桥中塔塔顶位移及加劲梁挠度的解析计算公式。研究发现,对单跨主缆施加均布荷载时,恒载大小对于主缆变形影响不大,主缆变形主要由缆的弹性伸长所引起,取决于主缆的轴向刚度及垂跨比;三塔两跨悬索桥的变形主要取决于中塔的变形以及主缆的伸长。建立三塔两跨悬索桥模型对本文公式进行验证,结果表明,公式能有效对塔顶位移及加劲梁挠度进行估算,可用于初步设计时对三塔悬索桥进行简化分析。In order to obtain the analytic formula for deformation of suspension bridge with 3 pylons and 2main spans caused by live load,an analytic formula used for calculating the deflection of a main cable of single span under uniform live load is derived. Through study the deformation of main cable caused by pylon top displacement and cable elongation comprehensively,the analytic formulas for calculating the deformation of middle pylon top and deflection of stiffening girder in suspension bridge with 3 pylons and 2 main spans are derived. The research shows that（ 1） the dead load has little effect on the deformation of the main cable when applying uniform live load along a single span,the deformation is mainly caused by the elastic elongation of the main cable and it depends on its sag-span ratio and the axial rigidity;（ 2） the deformation of3-pylon and 2-span suspension bridges is mainly caused by the displacement of the middle pylon and the elongation of the cable. A finite element model of the suspension bridge is established to verify the proposed formula. It shows that the proposed formulas are effective for estimating the displacement of pylon top and the deflection of stiffening girder,which could be used for simplified analysis of a three-pylon suspension bridge in preliminary design stage.

关 键 词：桥梁工程 悬索桥 简化计算 变形 中塔位移 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]