Resumen de Puentes de ferrocarril modulares integrales como alternativa al tablero isostático

Ricardo Rico Rubio, Sergio Couto Wörner, Jorge Cascales Fernández

• Isistatic precast decks with transverse joint on each span are a common solution for great length and short piers railway bridges. In this way rail expansion joints are avoided.

  As an alternative, aiming to design a structure with the hyperstatic behavior advantages, without rail expansion joints for any length of deck, low cost and reduced maintenance requirements, the CV- 95 Railway Viaduct, belonging to the Levante High-Speed line, Section: Orihuela – Colada de la Buena Vida (Alicante) is projected.

  The viaduct is located on a low bearing capacity soil and 0.29g seismic design acceleration.

  This structure has a total length of 337.50 m, divided into five independent integral modules of 63.0m + 3x70.5m + 63.0m length. Post-tensioned concrete deck, abutment and piers configure a monolithic element per module, so bearing devices are not necessary and maintenance requirements are reduced.

  Each internal module is composed of three 21.50m length spans and 3.00m length cantilevers in order to partially compensate the main spans. Intermediate piers between modules and sliding bearing devices over them are avoided by the cantilevers disposition. Initial and final modules are formed by three spans of 17.0m and 2x21.5m respectively, with a 3.0m cantilever at the end of the module.

  Each support axis is composed by 3 cylindrical concrete piers with a maximum height of 7.0m. The foundations of the viaduct are concrete precast piles in the whole structure.

  This bridge design gives the structure balance between the necessary stiffness required for high speed railway bridges and the necessary flexibility to provide an adequate behavior in terms of thermohygrometric deformations. In addition, the response against the seismic action is satisfactory as a behavior factor q=1.5 can be adopted.

  Any deck length without rail expansion joint could be achieved with this configuration by indefinitely repeating the intermediate module.