Enhanced Effective Thickness Method for Cantilevered Laminated Glass Balustrades

Cantilevered laminated glass balustrades supported by bearing in continuous base shoes are among the most ordinary applications of structural glass. The performance of laminated glass is commonly approximated with the Effective Thickness Method by Bennison, adapted from composite sandwich theory by Wӧlfel for a simply-supported beam under uniformly distributed load. Notably, significant underestimation of stress is observed with use of stiff structural interlayer where cantilevered laminated glass support is modelled as an idealized fixed-end moment. This paper seeks to address the accuracy of cantilevered laminated glass balustrade analysis for practical design by investigating the applications of Enhanced Effective Thickness (EET) method by Galuppi & Royer-Carfagni. A new expression for the EET coefficient is proposed here for laminated glass balustrades supported by bearing in a continuous base shoe. Performance of the Effective Thickness Method adopted in ASTM E1300 and two expressions of EET are compared with numerical models for stress and deflection, with particular regard to Example 13 of ASTM E1300.