Bivariate Quasi-Steady Model for Prediction of Roof Corner Pressures

Abstract

Extremely high-suction pressures generated beneath the conical vortex flow in the roof-corner region have a devastating effect on the building roofs in high-wind events. The application of quasi-steady theory near the roof corners of low-rise buildings deserves careful investigation for the appropriate assessment of the design wind loads. A synchronized incident wind and pressure data acquisition system was set up on the full-scale experimental building at Texas Tech Univ. Experiments were conducted systematically to simultaneously collect the incident wind and roof-corner pressure data under the influence of cornering winds. By using a conditional sampling technique, a bivariate quasi-steady model was established to incorporate the influence of both horizontal and vertical wind directional variations on the roof-corner pressures. Comparison between the measured pressures and the model-predicted pressures has shown that the quasi-steady theory in the suggested form is applicable in the roof-corner separated flow region where vortices are present. This conclusion further justifies the application and codification of quasi-steady approach for wind load assessment of low-rise buildings and other structures.