摘要
针对混凝土桥面板徐变过程对曲线钢混组合梁桥力学性能的影响,以某座5×30 m的曲线双工字钢板组合梁桥为工程背景,使用ANSYS软件建立精细化实体有限元模型,利用其中的Creep准则进行徐变等效计算,在考虑施工过程后研究钢混组合梁桥的徐变效应,并探讨不同加载龄期下的预制板对徐变效应的影响。研究结果表明:桥面板徐变导致的5跨连续梁跨中截面徐变应力在边跨最大,中跨次之,次边跨最小;横桥向上靠近钢纵梁处徐变应力大,远离钢纵梁处应力小;受到“弯扭耦合”影响,外侧钢纵梁应力变化比内侧钢纵梁应力变化更加明显,两者徐变应力值最大差异为32.28%。徐变导致的应力重分布使钢混组合梁中的桥面板应力向钢主梁转移,且钢梁上缘应力的增幅比下缘更为显著,边跨跨中钢梁上缘增幅是下缘的5.6倍。连续梁恒载变形会随着混凝土桥面板徐变持续增加,且边跨跨中附加挠度>中跨>次边跨;混凝土预制板加载龄期越长,徐变效应产生的主梁附加挠度越小,30 d的加载龄期下边跨徐变挠度是180 d加载龄期的1.5倍。
Aiming at the impact of creep process of concrete slab on the mechanical performance of curved steel-concrete composite girder bridge,ANSYS software was used to establish a meticulous solid finite element model of a 5×30 m curved double I-beam composite girder bridge as the engineering background,and the creep equal calculation was carried out based on the creep criterion.The creep effect of steel-concrete composite girder bridge was investigated after taking into account the construction procedure,and the impact of precast slabs on the creep effect at different loading ages was explored.The results show that the creep stress in the middle section of the 5-span continuous girder caused by deck plate creep is maximum at the edge span,followed by the middle span and minimum in the second side span.The creep stress is higher in the cross-bridge upward near the steel longitudinal girder and lower in the distance from the steel longitudinal girder.Under the influence of“bending-torsion coupling”,the stress change of outer steel longitudinal girder is more obvious than that of inner steel longitudinal girder,and the greatest variation in creep stress value between the two is 32.28%.The stress redistribution induced by creep causes the stress of bridge deck in the steel-concrete composite girders transfer to the steel main girders,and the increased stress at the upper edge of the steel girder is more remarkable than that at the lower edge,and the increase in the upper edge of the steel girder in the side span is 5.6 times that in the lower edge.The constant load deformation of continuous girder will continue to increase with the creep of concrete bridge deck,and the additional deflection in side span>middle span>secondary side span.The longer the loading age of the precast slab,the smaller the additional deflection of the main girder generated by the creep effect.The creep deflection of the side span at the loading age of 30 d is 1.5 times that at the loading age of 180 d.
作者
阮先虎
郭增伟
吴树广
RUAN Xianhu;GUO Zengwei;WU Shuguang(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Road and Bridge International Co.,Ltd.,Beijing 100027,China)
出处
《混凝土》
CAS
北大核心
2022年第3期25-29,34,共6页
Concrete
基金
国家自然科学基金(51878106)
重庆市自然科学基金面上项目(cstc2019jcyj-msxmX0818)
重庆市研究生联合培养基地建设项目(JDLHPYJD2020023)
桥梁工程结构动力学国家重点实验室开放基金(201501)。
关键词
钢混组合梁桥
施工过程
徐变效应
加载龄期
steel-concrete composite girder bridge
construction procedure
creep effect
loading age
