超大跨混合梁斜拉桥极限承载能力研究

发布时间：2018-05-06 16:44

本文选题：斜拉桥 + 混合梁　；参考：《桥梁建设》2017年05期

【摘要】：为研究超大跨混合梁斜拉桥在汽车荷载作用下的塑性区发展过程和极限状态下的破坏机理,以贵州鸭池河特大桥(主跨800m双塔双索面混合梁斜拉桥,边跨主梁采用预应力混凝土箱梁,主跨主梁采用钢桁梁)为背景,采用ANSYS软件建立全桥有限元模型,逐级施加汽车荷载,分析不考虑断索和考虑断索2种情况下该桥的破坏过程和承载能力。结果表明:随着荷载的增加,钢桁梁先产生受压塑性区和受拉塑性区,随后斜拉索到达屈服应力;不考虑断索情况下,斜拉索逐步屈服后钢桁梁受压塑性区和受拉塑性区不断扩大,结构最终失效,破坏表现出略好的延性;考虑断索情况下,第1根斜拉索屈服后断裂引起周围斜拉索的连续瞬时断裂导致结构破坏,破坏呈现明显的脆性;不考虑断索和考虑断索情况下,极限状态时的荷载系数λ分别为11.69和11.12。
[Abstract]:In order to study the development process of plastic zone and failure mechanism of large span hybrid girder cable-stayed bridge under automobile load, a 800m double tower and double cable plane cable-stayed bridge with main span of Yazhe River Bridge in Guizhou Province was studied. Using prestressed concrete box girder and steel truss girder as the background, the finite element model of the whole bridge is established by ANSYS software, and the vehicle load is applied step by step. The failure process and bearing capacity of the bridge are analyzed under the condition of not considering the broken cable and considering the broken cable. The results show that with the increase of load, the compressive plastic zone and the tensile plastic zone are produced first, and then the cable reaches the yield stress, and the failure of the cable is not considered. After gradually yielding, the plastic zone of steel truss beam under compression and tensile plastic zone expands continuously, the structure finally fails, and the failure shows a slightly better ductility. After the first cable yield, the continuous instantaneous fracture of the surrounding stay cable leads to the structural failure, and the failure presents obvious brittleness, and the load coefficient 位 is 11.69 and 11.12 respectively under the condition of not considering the broken cable and considering the broken cable.
【作者单位】：同济大学桥梁工程系;
【基金】：国家自然科学基金重点项目(51438010) 上海市自然科学基金项目(11ZR1440000)~~
【分类号】：U448.27

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