桥梁风障挡风性能的试验研究

Experimental study on windbreak performance of wind barriers on bridge

通过测速风洞试验,得到了孔隙率、障条宽度对桥梁风障挡风性能的影响规律,并对桥梁风障的模拟方法及其挡风性能评价参数进行了研究。试验结果表明,风障有效挡风高度约为2.0H(H为风障高度),在1.0H范围内,风速降低较多,在1.0H高度处,流场湍流度达到最大。孔隙率对风障挡风性能影响较大,随着孔隙率的增大,风障下游风速增大,湍流度减小。障条宽度对风障挡风性能影响较小,相同孔隙率时,障条宽度对风障下游湍流度的影响可以忽略。按压力等效定义的风速折减系数较好反映了风速的变化规律,能够来用定量评价风障的挡风效果。

Wind tunnel velocity tests have been carried out to investigate the windbreak performance of wind barriers on bridges considering different barrier porosities and widths, the wind barrier wind tunnel simulation method and evaluation parameter of windbreak performances are discussed in the paper. Test results show that the shielding region of wind barriers is about 2. OH （H is the height of wind barrier） and that wind speed decreases significantly when the height is below 1. OH. The turbulence intensity of the downstream flow on the wind barrier reaches the maximum at a height of 1. OH. Windbreak performance depends on porosity of wind barrier, wind speed will rise and turbulence intensity decreases with increasing porosity. Barrier width seems to have no relationship with windbreak performance; when porosity is the same, the effect of barrier width can be ignored. The wind speed reduction coefficient can be used to evaluate windbreak performance, which is defined by pressure equivalence.