Renovation of the Santiago Bernabéu Stadium. Relevant Structural Aspects in the East Turrets and in the New Access Towers

Abstract

This article describes the remodelling of the east side towers and the structural design of the interior of the new west side access towers, with particular reference to the interaction of these elements with the adjacent structures, both existing and new.

The existing towers, located at the two east corners of the stadium, originally supported the old roof truss, which was dismantled in the new configuration. The steel structure of the towers, made up of 4 braced columns, is reused both to create new floors in continuity with the east building and to form two new levels of stands, one cantilevered from the tower and the other above it, always in continuity with the stands on the east side of the stadium. The structure remains independent of the new building, with a series of joints between them. The new composite floors, made of steel plates supported by beams, are at a different level from the existing floors due to the changes in elevation in the new building. The prefabricated stands rest on a new metal structure consisting of two main edge beams aligned with the tower columns. A vibration analysis was carried out to assess the dynamic excitation of the stands.

Inside the steel structure of the west towers, a series of concrete floors and metal elements are developed to ensure vertical and horizontal communication within the stadium, including lifts, conventional stairs, escalators, walkways, and a perimeter ramp. The configuration of the solid reinforced concrete slab floors, has been designed to avoid supporting them on the  existing radial ribs of the stadium, thus avoiding additional loads. These floors rest on the outer steel shell of the towers and on concrete columns and cores inside. The main foundation of the towers consists of a pile cap with 25 piles, each 1800 mm in diameter, optimally positioned to support the load from the tower main columns and the steel skin truss. During the excavation phase to reach the pile cap level, a retaining wall of 450 mm diameter piles was installed in an oval perimeter, braced by temporary steel shoring.