摘要
为研究钢桁长度和高度以及合龙顺序和顶推力对钢桁加劲连续刚构桥长期变形的影响,以某在建钢桁加劲连续刚构桥为对象,采用有限元软件建立实体模型,考虑混凝土收缩徐变作用,对恒载作用下运营20年内的变形进行分析,系统分析钢桁长度和高度对连续刚构桥长期变形的影响程度,同时利用结构力学原理推导不同合龙顺序下的顶推力解析式,探讨合龙顺序和顶推力对连续刚构桥长期变形的影响。结果表明:钢桁长度和高度的增加均可使挠跨比下降,均能提高桥梁的整体刚度,考虑到实际结构受力及施工难度,建议钢桁长度在桥梁中跨长度的3/4~7/8范围内选择,挠跨比下降42.3%~44.1%,为避免出现设计过于保守的情况,建议钢桁高度取12 m,挠跨比下降43.8%;推导出不同合龙顺序下的顶推力解析式,只与桥墩和主梁的参数有关,计算简便、概念清晰,可指导实际工程中顶推力的确定;不同合龙顺序对钢桁加劲连续刚构桥长期变形的影响较小,施加顶推力后可明显改善钢桁加劲连续刚构桥的长期变形,建议在施工过程中采用先中后边的合龙顺序,同时施加顶推力,在运营20年时边跨和中跨最大竖向变形分别下降34.6%和34.2%。
To study the effects of steel truss length,height,closure sequence,and thrust on the long-term deformation of steel truss-reinforced continuous rigid frame bridges,finite element software was used to establish a solid model of a steel truss-reinforced continuous rigid frame bridge under construction.Considering the effects of concrete shrinkage and creep,the deformation over a 20-year operational period under constant load was analyzed,focusing on the influence of truss length and height on long-term deformation.Furthermore,analytical formulas for thrust under different closure sequences were derived using principles of structural mechanics to assess their impact on long-term deformation.The results showed that increasing both the truss length and height reduced the deflection-span ratio,thereby improving the bridges overall stiffness.Considering the actual structural forces and construction difficulty,it was recommended to select the steel truss length within 3/4 to 7/8 of the mid-span length,which achieved a 42.3%to 44.1%reduction in the deflection-span ratio.To avoid overly conservative designs,a steel truss height of 12 meters was suggested,yielding a 43.8%reduction in deflection-span ratio.The derived analytical formulas for thrust under various closure sequences,which relied solely on pier and main beam parameters,provided a simple and clear calculation method,offering practical guidance for determining thrust in engineering projects.The study found that different closure sequences had a relatively minor impact on the bridges long-term deformation.However,applying thrust significantly improved its long-term performance.A closure sequence that first completes the mid-span before the edges,along with the simultaneous application of thrust,was recommended.After 20 years of operation with this sequence,the maximum vertical deformations of the edge and mid-span decreased by 34.6%and 34.2%,respectively.
作者
占玉林
林金根
张程
张志强
邵俊虎
陈文尹
ZHAN Yulin;LIN Jingen;ZHANG Cheng;ZHANG Zhiqiang;SHAO Junhu;CHEN Wenyin(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Institute of Civil Engineering Materials,Southwest Jiaotong University,Chengdu 610031,China;School of Architecture and Civil Engineering,Chengdu University,Chengdu 610106,China;Sichuan Provincial Highway Planning,Survey,Design and Research Institute Co.,Ltd.,Chengdu 610041,China;The Seventh Engineering Co.,Ltd.of CTCE Group,Hefei 230022,China)
出处
《铁道标准设计》
北大核心
2024年第11期87-93,共7页
Railway Standard Design
基金
国家自然科学基金项目(52278220)
四川省科技计划项目(2021JDTD0012)。
关键词
高速铁路
铁路桥
钢桁加劲连续刚构桥
钢桁长度
钢桁高度
合龙顺序
顶推力
长期变形
high-speed railway
railway bridge
steel truss-reinforced continuous rigid frame bridges
steel truss length
steel truss height
closure sequence
thrust
long-term deformation
