Atrium of the Hotel Hesperia Tower, Barcelona, Spain

Abstract

The new Hotel Hesperia Tower has recently been inaugurated in Barcelona. This paper describes the design and construction of its glazed atrium, focusing on the prestressed bracing system which guarantees its stability. Several details are also described, emphasizing the possibilities of modern steel milling technologies to fabricate complex steel parts.The atrium is a 24 m high glazed volume covering an area of 30,5 × 20 m which connects the two buildings. This diaphanous space formed without a single column is used as a hall providing access to the conference rooms and the auditorium. The atrium is composed of two façades and a tilted roof which spans from the 6 th floor of the tower to the roof of the convention centre. StructureThe structure of the two façades and the roof of the atrium is a steel grid made of thin-walled rectangular hollow sections ranging from 60 × 60 × 3 mm to 250 × 150 × 8 mm. As no internal columns exist, the stability of both the roof and the façades relies on an internal bracing system (Fig. 2).The bracing system consists of several tension-compression members connecting the façades and the roof to three rigid points (steel nodes) floating in space 12 m above the ground. A 139,7 × 10 mm CHS (circular hollow section) shaft of steel grade S355 (i.e. having a yield stress of 355 N/mm 2 ) is used to join the three nodes. The tension-compression members are also circular hollow sections of steel grade S355 ranging from 139,7 × 6 mm to 219,3 × 7 mm. Four sets made up of three 39 mm diameter tension rods of steel grade S460 prestressed between 82 kN and 242 kN are used to keep the floating nodes in position. The lateral nodes fix one set each, while the other two sets are connected to the central node.The design of the two lateral floating nodes was a challenge as they connect a number of members which must meet in the same spatial point without any eccentricity. The Architect also