Glass Footbridge: Fid-Bau Portal

Glass Footbridge

Hamid, Yazmin Sahol / Parke, Gerard

Abstract When a footbridge is made of glass, it shows to the pedestrians the wonder and uniqueness of itself, i.e., its transparent characteristic. However, the perceived unwanted characteristics, such as the brittleness of glass may make it unsuitable, if used for a load-bearing structural member. But, using a toughened and laminated glass panel as the primary structural member can be practical because this toughened glass has a higher failure strength and is considerably safer when compared to ordinary glass. This paper began with an architectural drawing of a glass footbridge. Each primary beam of the footbridge was made from a large-sized glass panel. The bridge was modeled using beam finite elements and analysed using the finite element program, SAP 2000. The model was initially formed in 2D and analysed using two different support conditions. The analysis was repeated for a 3D model. The results of maximum moments, shear forces and deflections produced using both the 2D and 3D models and also using different support conditions are compared. The maximum stress was calculated and checked with the failure strength of toughened glass. The maximum deflection was also checked with the limiting value given in standard codes of practice. Connectors have been designed to connect the glass sub-panels together which have been used to form the large size glass panels, namely, the primary beams. The connectors have been designed and the stress level in the connection checked. Modal analyses using 2D and 3D models were also carried out to give frequencies and mode shapes of the footbridge under vibration. The frequencies are checked against the minimum value required according to standard codes of practice. All of the above checks were found to satisfy the relevant design criteria, and consequently the footbridge is now considered to be safe and ready for construction.