稳态冲击风作用下拱形屋面风压分布试验研究

为研究雷暴冲击风对拱形屋面的作用，基于相似准则进行了拱形屋面模型制作和雷暴风风场物理模拟，并完成了相应的冲击风风洞试验。通过改变矢跨比、高跨比及跨度，进行屋面风压的参数敏感性研究。通过改变屋面中心位置，研究竖向风场的作用。研究表明：屋面位于冲击风极值水平风速附近时，垂直于屋脊方向风压分布与矢跨比密切相关，屋面越靠近冲击风中心则升力越小；当屋面位于冲击风中心时，整个屋面均出现较大的正风压。

EXPERIMENTAL STUDY ON THE PRESSURE DISTRIBUTION OVER ARCH-ROOF SUBJECTED TO STATIONARY DOWNBURSTS

For the purpose of investigating the effects on the arch-roof caused by thunderstorm downburst wind, the model fabrication of arch-roofs, and the physical simulation of wind field of thunderstorm downbursts are conducted based on the similarity criterion. And corresponding wind tunnel tests are completed. The parametric sensitive studies are conducted through varying the span, ration of rise to span and ration of height to span. The effects of the vertical wind field are also investigated by placing the building on different positions. It is found that the pressure distribution along the direction perpendicular to the ridge is closely linked with the ratio of rise to span, in case of that the center of an arch-roof is located at where the horizontal wind reaches its peak value. It is also revealed that the closer the roof is to the center of the downburst, and consequently the smaller the lift force is. Furthermore, the whole roof would be subjected to a rather heavy positive wind pressure in case of that the centers of the roof and downbursts coincide.