Provisions and comparison of Chinese wind load standard for roof components and cladding

Abstract

This paper presents the main theoretical foundation and innovation of winad load provisions for wind loads on components and cladding in the newly-revised Standard for Wind Loads on Roof Structures (JGJ/T 481-2019). Generally, by introducing the concept of peak wind pressure coefficients, a more reasonable and convenient wind load determination for roof components and cladding can be obtained for structural designers. Moreover, based on extensive wind tunnel test data of external wind pressures on components and cladding of typical roofs, the corresponding peak external wind pressure coefficients are proposed, with more specific wind load zones. Regarding those large-span curved roofs, innovative external wind pressure coefficient values on detailed roof zones are firstly presented. In addition, according to comparisons, it is seen that the roof zones in the Chinese standard are similar to those in the Canada wind load code. The resulting peak external wind pressure coefficients in corner, edge and interior zones reach the international advanced level. Finally, optional three methods to determine peak wind pressure coefficient are also clearly specified, which are applicable to cases with different wind pressure time history lengths. All the development and improvement of the standard provide necessary supplement and reference for the international and Chinese wind-resisting design.