典型双坡屋面风压分布特性风洞试验研究

Wind Tunnel Test Study on Wind Pressure on Typical Gable Roofs of Lowrise Buildings

摘要:

通过表面压力测量风洞试验对低矮建筑的4种典型双坡屋面上的风压分布规律进行了研究.讨论了屋面和挑檐部分的平均和脉动风压系数在不同风向角下的分布特性,风场湍流强度对屋面脉动风压分布的影响,以及不同挑檐类型对双坡屋面风压空间分布的影响.试验结果表明:在屋脊及屋面边缘附近的平均风压系数绝对值要比屋面内部区域大；脉动风压系数随湍流度增大而增大,一般在迎风屋檐附近比较大；挑檐形式的改变仅对局部风压系数的影响较大,对整体风压系数的影响较小.这些结论为低矮建筑风荷载规范条文的修改提供了参考.

Abstract:

The wind pressure distribution on four types of typical gable roofs of lowrise building models are studied with pressure measurement wind tunnel tests.Three aspects are respectively discussed:the distribution characteristics of mean and fluctuating wind pressure coefficient on four types of gable roofs and eaves at different wind angles,the influence of turbulence intensity on the fluctuating wind pressure distribution and the influence of different roof types on the wind pressure spatial distribution.A detailed analysis of the experimental results show that absolute values of mean wind pressure coefficients are larger at roof ridge and near the edge of roof than on internal areas of roof.Fluctuating wind pressure coefficients increase with the turbulence intensities,which are larger on upwind roof than those on leeward roof.Generally,there are larger fluctuating wind pressure coefficients near the windward eaves.The changes of eave shapes only have more obvious influences on local wind pressure coefficients than those on overall wind pressure coefficients.These conclusions provide reference for modifying clauses about wind loads on lowrise buildings.