Bridges

When adopting the European Standard for road restraint systems EN1317, France faced the need to adapt its National Guidelines in order to allow anti-falling load systems to be qualified and used on its territory. The original French bridge parapets and anti-falling load systems were formerly covered by the Guideline called “Barrières de sécurité pour la retenue des poids lourds: Barrières de niveau H2 ou H3”. This document is describing the National bridge parapet BN4 usually used on the French bridges on which an additional screen was used to contain possible falling loads. In a research report “Mise au point des dispositifs de retenue par simulation de chocs”, numerical simulations were used to assess the performance of the BN4 barrier on which a screen to contain falling loads has been added.

This article proposes a procedure to be possibly adopted for any bridge parapets tested according to a Performance Standard such as EN1317 (or NCHRP350 or MASH) on which an anti-falling load would be installed. That procedure is including simulations that prove an acceptable level of reliability of the numerical models by comparing the simulations results with the real crash tests of the reference barrier without the additional anti-falling load screen. Then, a simulation of the heavy vehicle carrying a load able to fall during the impact on that barrier on which the anti-falling load screen would be added would be realized to check the performance of that anti-falling load system.