Wind-induced Internal Pressure and Net Pressure of a Super High-rise Building with Opening Under Downburst Action

Abstract:

Wind field of downburst was simulated in the atmospheric boundary layer wind tunnel by a self-made generator， and synchronous pressure measurements on the internal and external pressures of a typical high-rise building with an opening were conducted. The characteristics of internal pressure and net pressure as well as the internal pressure gain function were investigated in the terrain catergories downburst and B. Furthermore， orifice parameters were identified， and the theoretical calculation results of peak internal pressure were compared with the corresponding experimental results. Results show that both the mean and peak internal pressure coefficients decrease first and then increase with the increase of wind direction angle. Peak net pressures on both side-walls are the largest， which will easily lead to damage of side-walls. However， net pressure on the front wall with opening is the smallest due to the positive correlation between internal and external pressures. Besides， the amplitudes of internal pressure gain function in the wind direction of 50° are much larger than those in other wind directions， and the internal pressure energy at the Helmholtz resonance frequency is also significantly larger than that at other frequencies. Except for the wind direction angles of 70°~100°， the theoretical values of peak internal pressure coefficient are in good agreement with the experimental values.