Office building in Madrid

OTEP Internacional SA – Spain

Building use

Office building

Country/Region

Spain

Overview

The building is a 52 story office building, built in the new development of Madrid alongside 3 other towers. When finished it became the tallest building in Spain. The building has the shape of a rectangular prism, about 49×29 meters at the base, tapered at the angles to reach at the top an octagonal irregular shape.

Basic information (construction date, number of stories, gross floor area, adopted design code, engineer(s), Contractor(s), etc.)

Construction date: 2004-2009
Number of stories: 52
Gross floor area: 120,800m2
Adopted design code: Eurocode
Engineer(s): OTEP Internacional
Contractor(s): ACS, Actividades de Construcción y Servicios, S.A

Issue and/or innovation

The innovative aspect of this project relies in the peculiar solution adopted to avoid any on-side welding activity.

Reason for composite solution

The composite solution of the vertical columns was adopted after assessing other construction possibilities and was preferred after a technical-economic study of three possible alternative: concrete, steel or composite columns. The reinforced concretes solution was rejected as it was not suited for the slab structure and because it would have resulted in much larger columns that would have decreased the available floor area and also caused greater rheological effects. The steel solution would have required fire protection and/or architectural finishing, making the composite column solution adopted preferable as faster and less expensive than a steel option.

Specific solution/technical details

The composite solution adopted consist of 45 MPa SCC, B500S reinforcement, S460 steel core with HD type shape of varying size from the bottom to the top At the base the columns measure 95 cm in diameter and 70cm at the top of the tower. Each module of the column is 3-story tall (12,6meter in length) and was welded in the workshop to avoid any on-site welding. Each module features the connection pieces for the floor slabs and it is attached to the previous one by simple bolted steel plates. The element has a load bearing condition even before concrete is hardened so that the construction sequence is not affected by concrete curing times. At the base, the columns are connected to the foundation by means of a steel plate of 1250mm in diameter and 150mm of thickness made with S460 steel, anchored to the foundation with eight bolts of 45mm in diameter.

Impact or effectiveness

Each end of a column module was joined to the corresponding end of the previous section by simply resting one on top of the other and steadying the assembly with a bolted plate. The three-story length of each column module facilitated construction and reduced assembly operations, for the steel beams that support the floor slabs could be set into place with no need to wait for the concrete cover on the columns to set. The use of composite columns allowed the anticipation of the column shortening during construction and early life stages of the tower, so the steel elements resting one on top of the other were designed slightly longer than needed to allow for the shortening under compression.

References / Technical Papers Content

P. J. Blanco Temprano, C. H. Castilla, J.I. Vinals, “Torre de Cristal. Structural design for a high rise building”, Hormigón y Acero Vol. 59, no 249, págs. 71-87 julio-septiembre, 2008 ISSN: 0439-5689