两跨独柱墩曲线连续钢箱梁抗倾覆设计方法

Anti-overturning Design Method of Two-span Single-pier Curved Continuous Steel Box Girder

摘要:

独柱墩曲线连续钢箱梁是城市立交匝道桥常用的结构形式，但因其存在支座间距小、内外侧支座支反力差别大、边墩支反力小以及钢箱梁自重轻等诸多缺点，所以抗倾覆性能差便成为此类桥型普遍存在的问题。近年来发生的数十起该类型的桥梁倾覆事故，造成了严重的社会影响及经济损失。依据相关规范中关于桥梁上部结构抗倾覆计算方法，以实际工程为例，对两跨独柱墩曲线连续钢箱梁抗倾覆性能进行计算分析，得出采用双支座并且给主梁边墩位置处配重的方法，并从特征状态1及特征状态2两方面给出了提高该类型桥梁的横桥向抗倾覆性能的设计方法。

Abstract:

The single-pier curved continuous box girder bridge is a common structure of the urban interchange ramp, but it has many disadvantages, such as small support distance, large difference of support reaction between inner and outer supports, small side pier support reaction and light dead weight. Therefore, the poor performance of resistant overturning stability becomes the common problem of this bridge type. In recent years, dozens of such bridge overturning accidents have caused serious social impact and economic losses. According to the calculation method of anti-overturning of bridge superstructure in the code, taking a real project as an example, the anti-overturning performance of two-span single-pier curved continuous steel box girder is calculated and analyzed. It is concluded that the method of double supports and the additional weight at the side pier of the main girder is adopted. The design method improving the transverse anti-overturning performance of this type of bridge is given from the two aspects of characteristic state 1 and characteristic state 2.