Structural Design of Double Skin Facades as Damping Devices for Tall Buildings

Abstract

Double skin façade (DSF) systems are more effective environmental mediators than conventional single skin façade systems, and, due to this reason, their use for tall buildings has increased despite their higher initial costs. While many studies have been carried out on the environmental performance of the DSF system, research on its structural capability has been very rare. In tall buildings, excessive movement/acceleration can cause serious human discomfort problem. This paper investigates the potential of the DSF system as a structural motion control device in tall buildings. Two design strategies are investigated. In the first scheme, the connectors between the inner and outer skins of the DSF system is designed to have very low axial stiffness with a damping mechanism. Through this design, the dynamic motion of the primary building structure can be substantially reduced. However, the excessive vibration of the DSF outer skins is a serious design limitation. The second scheme is investigated to overcome this challenge. While DSF outer skins are fixed like those in conventional DSF systems, additional small masses are inserted into the DSF cavity and act as distributed tuned mass dampers (TMDs). Compared to the conventional TMD system, usually located in the occupiable space near the top of the building, the second scheme has the substantial benefit of saving this valuable occupiable space.