Consulting were appointed by McLaughlin & Harvey as Structural design
engineers for the new extension to the Belfast Waterfront.
The new steel framed extension to the Belfast Waterfront stretches from the existing building out to the edge of the River Lagan and provides an additional 7,000sq metres of floor space which can facilitate up to 5000 guests at any one time. There is an 1800sq metre main hall and a 700sq metre minor hall, each if which can be sub-divided to allow flexible layouts. These large clear span spaces were most cost effectively achieved through the use of a steel frame, particularly given the site constraints.
The facility has been designed to fit in with its surroundings, wrapping around the existing building and connecting to the existing facilities at multiple levels, though remaining an independent structure. The extension spans over the exiting services yard and service building on the riverside. Public access to the river has been maintained. The congested location proved challenging, being extremely restricted in terms of access and by surrounding structures and its proximity to the river.
The use of steel meant the construction works could be accelerated given the opportunity to pre-fabricate the frame off site in advance.
The ground conditions were extremely challenging, due to the presence of numerous below ground obstacles passing through the building footprint. These included historic quay structures, and a major storm sewer.
The complex primary structure was influenced by several factors. Firstly the spatial requirements for the extension involved column free spaces, a combination of single/double height spaces and partial intermediate floors, and the need to build over and around retained structure. Secondly the whole extension was to wraparound and tie into the existing Waterfront at various points and levels. Lastly there were complex load paths involved in the structure, with offset columns and transfer beams. This lead to a number of framing solutions being employed, using 1400 tonnes of steel.
Pre-cambered cellular beams were used along with metal deck composite concrete flooring, a degree of pre-cambering was calculated to provide level steel work after dead load deflection.
Extra levels were squeezed in as the building’s footprint gave very limited floor space. To give this intermediate floor sufficient ceiling height “Slimflor” construction was used, in conjunction with plated UC sections within the floor depth.
The main hall and the plant on the roof, are directly above these intermediate floors. To support both of these structures, “Cellform” beams were used to form the hall roof, this allowed services to pass through the beams and thus maximise ceiling heights. These cellform beams had a tapered section to provide integral roof falls (and provide a level soffit for rigging steelwork).
For the accommodation built over the service yard, cantilevered plate girder were used, as their supporting columns were offset, to maintain clear height for HGV access, to the Hilton tunnel which provides access to the service yard,
This project was Belfast City’s Council’s first use of BIM on a major project. The project was delivered using advanced modelling techniques, which minimised on site clashes and maximised the efficiency of design and construction. The use of BIM by the design team, allowed a digital survey of the existing building, providing geospatially accurate data, to be integrated into the 3D models for the extension. This was vital in fitting the new structure around the existing building and avoiding site clashes. All main designers produced information in a 3D environment using Autodesk REVIT. The design team were also able to export 3D information directly to subcontractors, such as the steelwork fabricators. The exchange of models produced more accurate quotes and fabrication models, which could be checked by the design team. The combined models allowed for coordination between disciplines, identification of problems, and resolution before reaching site.