Aerodynamic external pressure coefficients for rectangular buildings

Building constructions, buildings and structures

The object of the research is rectangular civil buildings located in dense urban areas of various configurations. The purpose of the work is to clarify the aerodynamic coefficients of external pressure on the surface of the facades of the building, depending on the type of urban areas and the direction of the wind flow. Method is an experimental research of wind flow around building models in a wind tunnel of recirculation type with imitation of the atmospheric boundary layer. The experiment provides for the study of various types of urban construction of building that are most often encountered in the design of microdistricts. Results. The distribution of wind pressure along the plane of the facades is very heterogeneous and depends on the type of urban construction of building, the direction of the wind flow, the height of the obstruction and the distance to them. It is impossible to offer a simple universal model for determining aerodynamic coefficients that takes into account all possible options for the interaction of a building with a wind flow. The simple schemes of aerodynamic coefficients proposed today in building codes are the only acceptable way to determine wind loads. Regulatory aerodynamic coefficients for the windward (ce=0.8) and leeward (ce=-0.5) facades of rectangular buildings ensure the collection of the wind load «in reserve» for almost any type of urban areas and obstruction heights. The experimental data for zones A, B and C of the main facades differ significantly from those indicated in Russian building regulations SP 20.13330.2016. The peak values of the aerodynamic coefficients cp,- for zone A are significantly less than those regulated by SP 20.13330.2016. These coefficients require clarification.