การทดสอบในอุโมงค์ลมสำหรับแรงลมต่อป้ายโฆษณาที่มีอาคารข้างเคียง

Abstract

Wind loads always take a major part in a design of billboard.  At present, neither Building Control Act nor standard of wind loading for building design in Thailand provides a procedure for determining wind actions on a billboard.  In addition, there are many factors affected on the determination of force coefficients for a billboard which are not completely described in international design standards.  For instance, the presence of existing nearby buildings (interfering buildings) tends to alter the effects of wind load acting on a billboard.  This study is an attempt to investigate the wind-induced interference effects on a rectangular plate model for a billboard. A wind tunnel studies for the billboard with interfering building models were conducted in a boundary layer wind tunnel to examine the aerodynamic coefficients of mean drag force and maximum torsion of the billboards by the high-frequency force balance technique.  The results of the mean drag force coefficient show that the upstream interfering buildings cause shielding effect by decreasing the mean wind load on the billboard, and a negative shielding (suction) is experienced when size of the interfering building increases, by contrast, the downstream interfering buildings can induce higher mean drag force up to 30%.   The interfering building may also induce significant increase in the maximum torsion on the billboard, especially for the cases of the large interfering buildings.