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大跨径混合梁连续刚构桥中跨采用大节段钢箱梁,减轻了结构自重,增加了桥梁跨度。目前修建的大跨径混合梁连续刚构并不多见,混合梁多运用于斜拉桥中,故混合梁连续刚构桥的诸多问题并未得到解决,如混合梁连续刚构桥的边中跨比,混合梁连续刚构的适宜墩高等。以瓯江特大桥主桥为背景工程,通过改变边跨跨径和桥墩高度来研究大跨径混合梁连续刚构桥的边中比及墩高性能。大跨径混合梁连续刚构桥在恒载效应、收缩徐变效应、活载效应以及结构自振特性等方面,边跨增大对结构整体刚度影响不大,仅对边跨刚度影响较大。总体上中跨效应大于边跨效应,中跨结构刚度对结构的整体刚度起决定性作用。对桥墩的高度变化影响分析表明桥墩高度不宜做的过低,否则效应值会出现突变,当墩高增加到一定程度,对主梁的受力性能改善程度有限。
Large Span Hybrid Girder Continuous Rigid Frame Span The large section of steel box girder reduces the weight of the structure and increases the span of the bridge. Currently, the continuous rigid frame structure of the long-span hybrid beam is rare, and the mixed beams are mostly used in the cable-stayed bridge. Therefore, many problems of the continuous rigid frame bridge with hybrid beams have not been solved. For example, Mid-span, mixed beam continuous rigid frame suitable pier higher. Taking the main bridge of Oujiang Super Large Bridge as the background project, the high side-to-side ratio and pier performance of the long-span hybrid rigid-frame continuous rigid frame bridge were studied by changing the span of the span and the pier height. In the aspects of dead-load effect, creep-shrinkage effect, live load effect and natural vibration characteristics, the long-span hybrid continuous beam rigid-frame bridge has little effect on the overall stiffness of the structure, and only affects the side span stiffness greatly . In general, the mid-span effect is greater than the side-span effect, and the mid-span structure stiffness plays a decisive role in the overall stiffness of the structure. The analysis of the influence of bridge pier height changes shows that the height of bridge pier should not be too low, otherwise, the effect value will change suddenly. When the pier height increases to a certain extent, the improvement of the bearing capacity of the girder is limited.