三幅邻近桥梁结构气动干扰效应的数值模拟及实验研究

Numerical Simulation and Experimental Study of Aerodynamic Interference on Adjacent Three Separated Deck Bridges

针对三幅邻近桥梁结构,在中幅箱梁和两侧对称组合梁的形心高差与中幅箱梁梁高比值(H/D_(0))为-2~+2之间的条件下,通过CFD模拟了三主梁的气动干扰效应并进行了风洞试验的局部验证。研究结果表明:在一定高差范围内,下游组合梁对中幅箱梁的脱涡存在抑制作用;在工程实际的固定间距下,三幅邻近桥梁结构各自的气动力均值在文中研究的中幅箱梁高差比范围内均有明显且规律的气动干扰效应,其中中幅箱梁敏感性最强、下游主梁次之、上游截面受影响最小。

The aerodynamic interference on the adjacent three separated deck bridges in different altitude difference ratios was investigated by CFD and is verified by the wind tunnel test.The altitude difference ratio(H/D_(0))is within the range of-2 and+2,where H is the difference of centroid height between the middle box beam and the two sides symmetrical composite girders and D_(0)is the height of the middle box.The numerical simulation results show that the downstream composite beams have an inhibition effect on the vortex shedding of the middle box beams in a certain range of height difference.At the actual spacing in project,the mean values of the aerodynamics of the adjacent three separated deck bridges are interfered with each other obviously and regularly in the range of H/D_(0)stu-died in this paper.The aerodynamic interference of middle box girder is the largest,that of the downstream girder takes second place,and that of the upstream girder is the least.