Tamina Canyon Crossing, Bad Ragaz, Switzerland

• Volkhard Angelmaier ^[1] ; Wolfgang Eilzer ^[1] ; Michael Müller ^[1] ; Holger Haug ^[1]
  1. [1] Leonhardt, Andrä und Partner Beratende Ingenieure
• Localización: VII Congreso Internacional de Estructuras: [resúmenes publicados en la revista Hormigón y Acero (ISSN 0439-5689), v. 68, especial Congreso, junio 2017], 2017, págs. 73-74
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • In 2007 the City of St. Gallen, Switzerland, has announced a public competition for a new bridge across the Tamina Canyon. The new road should bypass the village of Pfäfers in the northwest and lead into the district of Bofel. From Bofel to the district of Berg on the other side of the Tamina valley (fig. 1) a 400 m long bridge is built, crossing at the gorge at about 200 m height, becoming the most important and outstanding bridge construction in Switzerland of the last years.

    Bridging the Tamina gorge requires exceptionally high standards for a harmonious integration of the structure in the natural surroundings.

    For achieving this objective, sensitive handling of the boundary conditions and local conditions are essential. This is particularly the case for the technically demanding stages of construction of the bridge with the least possible disturbance of the nature reserve.

    The response to the invitation for this anonymous, unrestricted design competition was overwhelming with 24 entries and, within these, 14 arches of different shape and configuration had been proposed.

    In a two stage tedious selection process the jury came to the conclusion to select the presented scheme which had been developed by Leonhardt, Andrä und Partner.

    Summary of the concept and principal design aspects:

    • Tamina gorge to be crossed column-free (reinforced concrete arch with 265 m span).

    • End region of the hillside areas had to be also column-free (rigid frame with 89 m span Bofel side).

    • Construction of the main opening had to be by balanced cantilever method with a temporary stay system.

    • Integral structure by monolithic connections of all main components (bearings only at the abutments) and thus a high degree of durability, robustness and redundancy. Use of concrete hinges at all piers.

    • Extension of the typical appearance of arch structures by radial arrangement of the piers which brings distinct static advantages due to shorter end spans and in general (compared to vertical piers) showing a very favorable loading for the arch.

    • The three small piers over the arch have as well from solid sections.

    In elevation these appear very slender since they are provided with hinged supports at the superstructure and at the arch.

    The presentation will focus on the design concept, some particular details such as the concrete hinges and their design criteria, as well as the challenging construction process.