3D rotation

The RESTON® SPHERICAL bearing, typically mageba’s optimal solution for accommodating large structure rotations about any horizontal axis, has now been developed for a project in Sri Lanka to also facilitate rotations about a VERTICAL axis

The ITC Colombo One project involves the construction of a striking new building in Sri Lanka's capital, Colombo, boosting the country’s real estate market. The project includes a 49-storey residential tower and a 28-storey hotel tower, connected by a 54m-long sky bridge approximately 100 m above ground level. Most spectacularly, the multi-level bridge will feature full-length infinity swimming pools along both sides of its open-air top level.

The unique design of the bridge, supported at two levels on each tower, required the development of a unique structural bearing solution. Eight bearings were required, four at each support level, each able to accommodate rotations about any horizontal axis. Just one bearing was required to be of the fixed type, preventing movements in any direction, and the other seven were to be of the guided-sliding type, accommodating sliding movements of up to 540 mm along one axis. What made the requirements very special, however, was the need to make all structural bearings allow rotations about a vertical axis, while also resisting horizontal forces, when the bridge swivels in a horizontal plane due to out-of-phase movements of the two towers. These movements and rotations were to be facilitated by a structural bearing system that would be stable, easily replaceable in their relatively inaccessible locations, and very durable – considering especially the building’s corrosive marine environment.

mageba addressed this challenge by specially adapting the tried-and-trusted RESTON® SPHERICAL bearing – the fixed and guided-sliding versions of this – to also accommodate rotations about a vertical axis. This was achieved by designing each bearing with two functional parts – an upper part, with the rotational calotte element on a piston inside a cylinder to allow 3D rotations and no movements, and a lower part facilitating sliding movements as required. And so the RESTON®SWIVEL bearing was born.

The structural bearings are scheduled to be installed in the coming months, having already been fabricated at mageba’s regional hub in Kolkata, India – completing another project in which mageba has demonstrated its ability to develop and deliver tailor-made solutions to meet the particular bearing requirements of virtually any bridge or building project.

Bridge designer: Sterling Consultant Services, Mumbai
Contractor: Larsen & Toubro Limited, Chennai Construction
Owner: WelcomHotels Lanka

Image © www.sapphireresidences.lk

The ITC Colombo One project involves the construction of a 49-storey residential tower and a 28-storey hotel tower, connected by a sky bridge

Image © www.sapphireresidences.lk

The open-air top level of the sky bridge will contain two swimming pools, each the full length of the bridge

Image © www.sapphireresidences.lk

The multi-level sky bridge – 54 m long and at a height of approximately 100 m above ground level – must be able to rotate on plan to accommodate movements of one building relative to the other

Design rendering of the specially developed RESTON®SWIVEL pin bearing that will form the bridge’s fixed point at the lower support level (Vmax = 12,000 kN, Hmax = 3,900 kN)

Design rendering of the specially developed RESTON®SWIVEL guided bearings, similar to the pin bearing but additionally designed to accommodate sliding movements of up to 540 mm

A RESTON®SWIVEL guided bearing as fabricated for the project at mageba’s regional hub in Kolkata, India