大悬臂展翅预应力混凝土宽箱梁桥极限承载力分析  

Analysis of ultimate bearing capacity of prestressed concrete box-girder bridge with large-cantilever-wing

作　　者：余晓琳[1] 贾布裕[1] 杨铮[1] 颜全胜[1] 

机构地区：[1]华南理工大学土木与交通学院,广东广州510640

出　　处：《铁道科学与工程学报》2015年第6期1379-1386,共8页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51208208);中央高校基本科研业务费专项资金资助项目(2014ZZ0019);广东省交通运输厅科技项目(科技-2014-02-013)

摘　　要：针对大悬臂展翅结构的极限承载能力问题,以某大悬臂展翅预应力混凝土宽箱梁桥为实际工程背景,建立精细的空间有限元模型进行数值分析。考虑结构几何非线性和材料非线性,研究偏心集中荷载、对称集中荷载、均布荷载3种工况作用下,结构的极限承载能力及裂缝的分布规律。结果表明,对称加载形式的极限承载能力大于非对称加载形式的极限承载能力;非对称荷载作用下,桥梁应力及裂缝分布也具有较大非对称性,且悬臂板根部更加容易出现裂缝,均布荷载作用下,桥梁边跨应力状况劣于中跨。To study the ultimate bearing capacity of the large cantilever structure,an accurate space finite element model was built for numerical analysis with the background of a prestressed concrete box- girder bridge with large- cantilevev- wing. Taking into account of the geometric nonlinearity and the material nonlinearity,the structure ultimate bearing capacity and the distribution regularity of cracks under three load cases（ eccentric concentrated load,symmetrical concentrated load and uniform distributed load） were analyzed. It is concluded that the structure ultimate bearing capacity under the load case of symmetrical load is larger than that under the case of asymmetrical load; the distributions of the stress and cracks under the load case of asymmetrical load are also asymmetrical and cracks are more likely to appear in the root of the cantilever wing. The stress condition of side span is worse than mid- span under uniformly distributed load.

关 键 词：极限承载力 大悬臂 展翅箱梁 非线性 裂缝 

分 类 号：U448.215[建筑科学—桥梁与隧道工程]