摘要
以3跨变截面箱梁弯连续刚构桥为研究对象,分别采用平面有限元和空间有限元方法计算了自重作用下控制截面的剪力滞系数,并对剪力滞效应进行了分析,主要对弯曲半径、宽跨比、粱高比、墩高、施工阶段等因素对变截面箱梁剪力滞效应的影响进行了分析了。结果表明,自重荷载作用下,弯桥半径对剪力滞系数影响较大,沿纵桥向变化非常明显,但任一截面中心点的变化不大;边跨支座断面的截面应力分布最不均匀;跨径不变,随着曲率半径的减小,剪力滞系数越大,应力的不均匀分布也加剧变化;梁高比越大,剪力滞系数越大;墩越矮剪力滞系数越小,高墩时,墩高的变化不会影响剪力滞系数的分布。在悬臂施工阶段中,悬臂端截面的应力剪滞系数随着施工悬臂长度的增加而减小。
Based on the research of three-span curved continuous rigid frame box girder bridges with taper section, plane and spatial Finite Element Methods are used for calculating the shear-lag coefficient of the dangerous section under the action of weight. The effect of shear-lag of box girder with taper section on bridge radius, ratio of width to span, girder height ratio, pier height and construction phases are analyzed. It is found that, shear-lag is easily influenced by radius under the action of deadweight and the effect along the longitude is obvious but the difference is small at the central point of any section; the section stress distribution is uneven at the section of side-span bearing; if the span is the same, the shear-lag coefficient and the stress uneven distribution are greater with the radius of curve reducing; the shear-lag coefficient is greater with girder height ratio increasing; if the pier height is lower, the shear-lag coefficient will decrease. The shear-lag coefficient distribution is almost the same with the change of pier height of tall pier. In the cantilever construction stage, the shear-lag effect of the cantilever section＇s stress will decrease with the cantilever length increasing.
出处
《公路交通科技》
CAS
CSCD
北大核心
2007年第8期87-91,102,共6页
Journal of Highway and Transportation Research and Development
基金
交通部西部交通建设科技资助项目(200231822329)
关键词
桥梁工程
高墩大跨弯桥
空间有限元法
剪力滞效应
正应力
bridge engineering
high-pier ＆ long-span curved bridge
spatial FEM
shear-lag effect
normal stress
