Seismic Analyses Of The Messina Bridge Project
Free (open access)
S. Hernández, L. E. Romera, A. Baldomir & F. Bravo
In this paper several preliminary works developed to determine the seismic response of the Messina Bridge project are presented. Firstly the different types of non-linear structural models developed are shown, including global models for the macro-level static and dynamic analysis, and local models for the micro-level analysis. Then, the analyses and several results obtained for static and nonlinear seismic time histories analyses are explained. Finally, the results of the Messina local tower model with a longitudinal push-over analysis are presented. 1 Introduction The suspension bridge over the strait of Messina (figure 1) will link Sicily and Calabria with the world longest center span of 3.300 m. The preliminary design used as the basis of the analysis that appear in this article, was developed by Chodai Co., Ltd. in 2004, following the analysis and design specifications for the bridge (ref.TSA002) developed by the concessionaire Stretto Di Messina S.p.A which carries out the research, design, construction and operation of the bridge. Figure 2 shows the transversal bridge section and one of the towers. The bridge section has three principal girders, one central for two railways and two laterals for road traffic. These girders are connected with transversal girders spaced 30 m. in the longitudinal direction, and suspended at its ends from hangers that connect them with the main cables. The main cables are connected to the ground at the splay saddle in the anchorage, and to the tower saddle at the towers. Figure 3 shows a realistic visualization detail of these girders. The towers as well as the girders and the suspension system were executed in structural steel of qualities between S355J0 and S420J0. Each tower has an approximate height of 382 m, with a self-weight greater than 5 x 105 kN, and is composed of two inclined columns connected by four transversal girders.