大跨度柏式钢桁梁桥厂制预拱度设置研究  

Study on Plant Precamber Setting of Large-span N Type Steel Truss Bridge

作　　者：蔡禄荣[1] 王荣辉[1,2] 王钰 

机构地区：[1]华南理工大学土木与交通学院,广东广州510640 [2]华南理工大学亚热带建筑科学国家重点实验室,广东广州510640 [3]中铁十三局集团第三工程有限公司,辽宁沈阳110043

出　　处：《铁道学报》2013年第4期96-101,共6页Journal of the China Railway Society

基　　金：国家自然科学基金(50978105);广东省交通厅科技项目(2007-15)

摘　　要：大跨度钢桁梁桥的预拱度设置较为繁琐,除需考虑获得匀顺的预拱度曲线外,还应兼顾杆件伸缩的统一性、错孔效应和次应力等影响,然而对于该类桥型的预拱度设置至今没有统一的规范和计算方法。为了获得较为理想的预拱度曲线,针对常用的柏式下承式钢桁梁结构,采用有限单元法,以相对预拱度作为输入荷载参数,推导杆件的伸缩公式。该方法可被编译成计算程序并做成对照表格,易于获得与理论预拱度较为一致的线形。通过与榕江特大桥的预拱度设计结果对比,证明该方法实用可行,从而为类似桥梁的预拱度设置提供理论依据。Setting of plant precamber of large-span steel truss bridges is complex, for both smooth precamber curves and in fluence of unitarity of member bars,staggered effect of bolt holes and the secondary stresses need to be taken into consideration. However, there has not been any universal standard or computing method for plant precamber setting so far. Applying the finite element method with the frequently used N-type through steel truss structure and taking the relative precamber between two adjacent nodes as the input displacement load, computational formulas for extension and contraction of member bars were deduced so as to obtain satisfying precamber curves conveniently. Corresponding computing programs were compiled and comparison tables were made to obtain precamber curves close to the shapes of theoretical precamber curves. Comparing with the precamber design of the Rongjiang Extra-long Bridge, the proposed method proves feasible and so theoretical basis is possible to be provided for plant precamber setting of N type steel truss bridges.

关 键 词：钢桁梁 厂制预拱度 有限单元法 

分 类 号：U448.13[建筑科学—桥梁与隧道工程]