不同斜交角度简支T形梁桥的基频计算及试验分析

The Fundamental Frequency Calculation and Experimental Analysis of Different Skew Angle Simply-supported T-shaped Beam Bridge

以某装配式后张法预应力混凝土简支斜交T形梁桥为工程实例,采用Midas Civil软件建立空间梁格模型,对不同斜交角简支T形梁桥的动力特性进行分析,提出斜交T形梁桥的基频随斜交角度变化的计算修正公式。分析表明:当斜交角小于20°时,竖向频率可以按照正交桥计算,当斜交角度为20°~55°时,频率与正交桥差异相差很大,计算冲击系数明显增大,直接影响桥梁结构内力设计。因此,在斜桥设计时必须引起足够重视。通过现场动荷载试验测试得出基频与拟合公式计算结果十分接近,说明该拟合公式能够较准确计算斜交T形梁桥的竖向基频值。

Taking a fabricated post-tensioning method prestressed concrete simply-supported skew T-shaped beam bridge as the engineering example, using Midas Civil software, this paper established the space grillage model to analyze the dynamic performance of different skew angle simply-supported T-shaped beam bridge, and it also put forward the calculation correction formula of skew T-shaped beam bridge fundamental frequency that changed with the skew angle.