Residential in Rotterdam

ABT B.V. Ingenieursbureau Delft – Netherlands

Building use

Other

Country/Region

Netherlands

Overview

The building is a luxury residential development composed of a portion of “sky apartments” in the upper section and a portion of “city apartments” in the lower portion of the tower. The building has an additional volume of 9 stories with a huge cantilever of 16 meters.

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

Construction date: 2003-2005
Number of stories: 43
Gross floor area: 57,530m2
Adopted design code: –
Engineer(s): ABT Delft
Contractor(s): Besix

Issue and/or innovation

The tall tower is formed by a sequence of three different structural systems. The upper portion is made with a steel frame with concrete core, the lower portion is made with a concrete structure while the bottom 2 floors are supported by a composite steel-concrete structure. On the second floor, the forces must be transferred from the concrete into the steel again. Only the walls at the core in the middle of the building extend into the basement.

Reason for composite solution

The composite elements of the lower portion are needed to transfer the vertical forces acting on the perimetral columns back to the central core, by means of a composite truss construction.

Specific solution/technical details

Despite the use of concrete quality B65, very heavy welded I-shaped profiles of 940 mm high with a flange width of 300 mm are required. The thickness of both the body and the flange of these hammer pieces is 100 mm and the length maximum 2900 mm. Originally this connection was designed with a solid steel steel piece of 1600x300x500 mm. However, because such a block is only available as a semi-finished product, the steel quality of which could not be guaranteed over the entire thickness, an I-shaped profile composed of plates of maximum thickness in steel quality S355. The transfer of the horizontal forces from the concrete walls to the underlying braced steel structure takes place via cast-in profiles. Welded dowels transfer the horizontal forces to the floor of the second floor. The same floor must remain vertically connected to the concrete walls above. Reinforcement has also been welded to the steel beams for this purpose. The horizontal forces can ‘cross over’ via the floor to the stability elements of the heavy steel-concrete construction on the ground floor
Also the truss elements are made of steel hollow profiles of 600×600 mm with a thickness of 25mm for the diagonal elements a thickness of 40mm in the vertical elements filled with concrete. The non-visible vertical columns in the underground floors are also made of composite construction with a very thick steel profile (up to HEM 600) encased in concrete. Though not visible in the attached drawing, two rows of shear studs are welded to the HEM web to enhance composite actions.