SR39 The behaviour of external glazing systems under seismic in-plane racking (2007)

The in-plane behaviour of external curtain wall glazing systems when buildings respond to seismic loading is not understood. This is a cause of great concern for the safety of pedestrians and occupants of buildings during earthquake attacks.

This work forms the second phase of a research programme undertaken by BRANZ to determine the performance of external glazing systems used in multi-storey buildings when subjected to seismic-induced racking. The first part is reported in SR17.

The objective of this study was to verify that the performance of curtain wall glazing systems can be adequately modelled within a laboratory environment. Another objective was to identify the parameters that affect the performance of curtain wall glazing systems when subjected to seismic in-plane racking, thereby enabling a suitable test method to be developed.

This report describes the experimental racking tests carried out on five full-size generic glazing systems. The parameters studied included displacement rates (period), boundary conditions (building deformation characteristics and two specimen configurations), number of cycles at each amplitude and different incremental cyclic displacement. To investigate the effect resulting from torsion, a 30 mm out-of-plane skewness was also introduced to three systems.