Conception parasismique de culées préfabriquées

ABSTRACT:

Résumé

Le réseau routier québécois est bien développé, mais plusieurs des structures de ponts le composant sont vieillissantes et nécessitent maintenant des réparations ou un remplacement. Par contre, les particularités propres au Québec, telles que l'hiver, l'achalandage des routes et le risque sismique, rendent la conception et les travaux de construction ou de réfection plus complexes. La construction accélérée des ponts (CAP) se présente alors comme une option prometteuse pour résoudre certaines des problématiques de la construction de ponts au Québec. Il s'agit d'une technique de construction employant des éléments préfabriqués en usine, qui sont ensuite assemblés en chantier. La CAP est utilisée depuis plusieurs décennies pour certains projets d'envergure, mais l'est encore très peu pour les ponts courants. Lorsqu'elle est bien réalisée, elle permet une meilleure qualité, performance et durabilité des éléments structuraux, ainsi que deQuebec's road network is well developed, but many of its bridge structures are aging and now require repairs or replacement. On the other hand, the specific characteristics of Quebec, such as winter, road traffic and seismic risk, make the design, construction or rehabilitation work more complex. Accelerated bridge construction (ABC) presents a promising option to solve some of the problems of bridge construction in Quebec. This construction technique uses factory precast elements which are then assembled on site. ABC has been used for many decades for some large-scale projects but is not yet used for common bridge construction. When appropriately done, it allows for better quality, performance, and durability of structural elements, as well as saving time and money. Studies carried out over the past twenty years at Polytechnique Montréal have shown the potential of ultra-high-performance fibre reinforced concrete (UHPFRC) in the seismic rehabilitation of bridge piers and the construction of precast piers. UHPFRC is a material which achieves exceptional performances, especially in tension, by adding steel fibres to the concrete matrix. The project therefore aims to develop precast abutments with a UHPFRC connection between the stem wall and the footing, which can be used in the context of ABC. Two precast stem wall concepts were proposed following the previous phases of the project: an option with 140 mm thick walls, filled with concrete during construction on site, and an option with 225 mm thick walls, filled with a non-participating material. The objectives of this project are the numerical study of the abutment behaviour for the proposed concepts, and the experimental study of lap splice connections between the stem wall and the footing.»s économies de temps et d'argent.