Design and Testing of Cable Catchment Systems for Historic Window Blast Protection

Abstract

The Federal government mandates blast protection for all of its facilities, which can be particularly challenging for existing buildings, especially those of historic interest. The blast protection of historic facades is one of the most challenging aspects since historic window structures offer little blast resistance and it is critical to preserve the existing aesthetic. As a solution to this issue, Hinman Consulting Engineers, Inc. (Hinman) investigated the potential application of a window cable catchment system as a means of cost-effective blast protection. This paper discusses the unique design features and analytical modeling of the cable system on exterior windows to resist potential external blast threats. The cable catchment system consists of steel cables installed behind glass panes and anchored into the structural system above and below each window. A three-dimensional finite element (FE) model was developed to investigate the performance of the window catchment system. This analytical model was then validated by the results of shock tube tests sponsored by the General Services Administration (GSA). Finally, the key parameters of interest in the performance of different cable system configurations including the interaction between cables and glass panels, details of the system configuration, and the reliability of the system are outlined. The results of this study show that the cable systems demonstrate considerable potential to provide efficient blast protection for existing window systems.