Vehicle impact simulations on noise barriers in intrusion zones

We were invited to participate in the design of transparent and opaque noise barriers. These barriers were installed in recent years on the Turcot Interchange and on the approaches to the Samuel-de-Champlain Bridge in Montreal. These walls have the peculiarity of being located in an intrusion zone and are therefore subject to impacts from a wide range of vehicles, notably semi-trailers weighing over 36 tonnes.

As part of this project, we carried out impact simulations between 2017 and 2019. To this end, wall sections ranging from 21m to 55m in length were simulated using LSDYNA software for TL3, TL4 and TL5 impact conditions, according to NCHRP Report 350. One of the key elements of the project was to limit the risk of debris projection affecting nearby traffic. It was therefore required to characterize the failure of the wall's mechanical elements.

One of the most significant challenges of the project proved to be the limited capacity of anchors on the back of concrete guardrails. We had to evaluate and optimize different concepts. We also had to ensure that the impact would not cause debris to be thrown under or near the interchange, and that the wall would not cause additional hazards to drivers and nearby traffic lanes. Efforts were made at the start of the project to characterize the possible failure of wall elements such as reinforced PMMA panels and concrete in order to increase the confidence level of the model and conclusions regarding debris projection.

Result :

At the end of the project, the Ministère des Transports et de la Mobilité durable and Jacques Cartier and Champlain Bridges Incorporated approved the noise barrier concept. We then proceeded with manufacturing and installation. No impact has been reported to date.