关河大桥桥型方案的比选

Comparison and Selection of the Bridge Type Plan

以金沙江流域关河大桥的桥型方案比选为例,介绍了桥位设计流量、主跨最小长度、最高洪水位及最低桥面标高的计算与确定方法;依据项目的功能和特点确定了比选原则及可供比选的桥型,同时结合桥位水文、地质条件,对连续刚构桥、箱型拱桥等大跨径桥梁在工程造价、施工难易程度等经济技术方面进行综合比较,优选出最佳桥型方案。

Based on the bridge over the Jinsha river,this paper presents the calculation and determination methods of the design flow,the least length of main span,the highest flood stage and the lowest floor elevation.According to the performances and characteristics of the item combined with the bridge site hydrology and geological conditions,the principles of the comparison are determined by the comprehensive comparisons of the engineering cost,the installation difficulty,as well as the easy level of the large span bridge such as continuous rigid frame bridge,box arch bridge and so on.Finally,the best bridge type was optimized and selected.