Design Awards: 2016

Energy from Waste Facility, Ardley

Energy from Waste Facility Ardley

Architect
Architecture & Planning Solutions and TSP Projects

Structural Engineer
TSP Projects

Steelwork Contractor
Bourne Steel Ltd

Main Contractor
Clugston Construction

Client
Viridor

The facility has been constructed to treat 300,000 tonnes of non-recyclable waste each year, diverting at least 95% of Oxfordshire’s residual municipal waste away from landfill and generating enough electricity to power 38,000 homes.

The completed building structure is up to 229m long varying from 38m to 70m wide and between 15m and 35m high. Steel was the natural choice for the main frame due to the convex and concave shapes in both plan and elevation, together with clear height and internal space requirements.

Although the structure looks like one building, internally under the cladding it is split into several zones incorporating different designs and resulting in over 2,000 tonnes of structural steelwork being used. With the processing plant taking up most of the internal areas, the use of models was crucial to make sure there were no clashes between key plant, equipment and their secondary supports and the main frame.

Within the waste bunker, cranes operate at high speeds with high acceleration and breaking forces, together with a grab swing with large pick-up loads. In this area the crane beams and all connected steel members had to be designed and fabricated to comply with Execution Class 3 requirements due to the high fatigue requirements. These areas were located on top of an 18m high concrete structure which limited access for connections to alongside one elevation only. To overcome this, a removable MEWP platform was designed and constructed to fit on the top of the concrete structure so connections could be accessed.

As the internal process plant and associated secondary steelwork for access and support were constructed in advance of the main frame enclosure, the use of modular roof assemblies, some weighing 40 tonnes, had to be used so that the 35m high roof could be infilled with steelwork to allow support for the cladding systems. These modular assemblies were installed using 800 tonne mobile cranes due to having to work over the constructed plant and metalwork areas, and also only having access along one side of the building.

The majority of steelwork was hot-dip galvanized to provide the necessary corrosion resistance and low maintenance requirements due to the difficulties in accessing the members whilst the building is in operation. Other areas, mainly accommodation areas or rooms with daily occupancy, were painted with intumescent coatings to achieve the specific fire resistance requirements.

The project was delivered on programme and to budget.

Judges’ Comment

A large and highly complex industrial plant has been enclosed by an undulating structural steelwork envelope. Site logistics and difficult construction phasing resulted in great challenges to the fabrication and erection which required modularisation and bold management.

The construction above column-free spaces to such a complex timetable was impressive.

Energy from Waste Facility, Peterborough

Energy from Waste Facility Peterborough

Architect
BHP Design (UK) Ltd

Structural Engineer
MLM Consulting Engineers Ltd

Steelwork Contractor
Severfield

Main Contractor
Interserve & Babcock Wilcox Volund

Client
Viridor Waste Management

The facility annually processes 85,000 tonnes of residual waste generating 7.25MW of electricity, enough to supply 15% of the homes in Peterborough, and reducing the volume of household waste sent to landfill by up to 94%.

The facility needed to be able to adapt to changing floor layouts around the main plant and it was important to minimise movement of the plant-support steelwork. An independent clear-spanning lattice steel column and lattice roof beam structure enabled maximum flexibility of the internal floorplates, and prevented the transfer of wind load to the internal plant support steelwork.

The fabrication and erection was undertaken in stages, allowing for part of the structure to be built and then large items of plant installed, before construction of the remaining building envelope.

Judges’ Comment

This is an architecturally elegant and practical solution, enabled by structural steelwork. The challenge of constructing an envelope around such a complex plant is that the requirements of that plant override all others.

The successful conclusion is a tribute to the great efforts applied.

New Watford Market

New Watford Market

Architect
tp Bennett LLP

Structural Engineer
AECOM

Steelwork Contractor
Nationwide Structures Ltd

Main Contractor
TSP

Client
Watford Borough Council

With a restricted budget and a tight one year delivery schedule, using recycled shipping containers was a cost-effective way of creating an open and inviting contemporary look and feel. The canopy roof was seen as a key feature.

An independent steel frame to support the canopy has been carefully detailed and the use of elliptical hollow sections for the portal frame columns and beams is both economical and elegant.

Every steel detail has been carefully considered, with the smallest connections designed to offer a modern, sleek look. The stretched fabric is raised up in conical forms with the use of stainless steel cables acting on a central glazed ring in the centre of each cone. These 1.5m diameter rings allow natural light to stream through. The lighting design works in harmony with the canopy, using fittings that project light both up and down.

Judges’ Comment

This is an inventive response to an awkwardly shaped site next to a noisy ring road with restricted access. It successfully employs a neatly detailed prefabricated tubular frame with a membrane canopy under which shipping containers provide lockable market stalls.

The new market has proved popular with traders and public alike.

University of Cambridge Primary School

University of Cambridge Primary School

Architect
Marks Barfield Architects

Structural Engineer
Parmarbrook

Steelwork Contractor
William Haley Engineering Ltd

Main Contractor
Willmott Dixon Construction Ltd

Client
North West Cambridge Development, University of Cambridge

This is a new school that encompasses classrooms, group rooms, performing arts and multi-purpose halls, dining hall, library, storage facilities, kitchen, WC and changing rooms.

The Communal Block, approximately 35m x 26m on plan, comprises a steel frame with precast hollow core slabs at first floor and roof level.

The Cluster Building is a circular, single storey steel frame with lightweight roof. Its outer radius is 46m and its inner radius is 24.5m.

The Inner Canopy is a circular glazed steel canopy 2.7m wide.

By using steel an open-plan arrangement encompassing long spans with minimum depth was achieved, providing internal flexibility and future adaptability in terms of layout and wall partitioning. The weight of the superstructure was also kept to a minimum which minimised the size and depth of foundations.

Judges’ Comment

This innovatory school will form the focus of a new community on the outskirts of the city. Circular in plan and arranged around a central garden courtyard, the simple elegant steel frame achieves long- span lightweight construction despite the foundation and programme constraints.

The steelwork framing contributed to a notable completion in two years from inception.

Sports Hall and Sixth Form Centre, Channing School, London

Sports Hall and Sixth Form Centre

Architect
BuckleyGrayYeoman

Structural Engineer
Heyne Tillett Steel

Steelwork Contractor
TSI Structures Ltd

Client
Channing School

Height restrictions for the sports hall roof, from both above and below, led to a creative double-pitched solution with no central support using four sloped steel trusses which span 34m along the length of the building.

With only a 30 degree pitch, large horizontal forces from the roof attempting to spread are resisted by a series of exposed Macalloy ties between perimeter columns and the central valley chords of the trusses. Once all roof steelwork was in place and connections fully tightened, central roof props were lowered gradually in unison.

Stability has been provided by portal action to the perimeter columns and braced bays at gable ends.

The upper floor of the sixth form centre is a clear span steel frame also tied with exposed triangulated Macalloy cables.

Judges’ Comment

This project enhances sports facilities at a well-established girls’ school and is on a constricted site in an historic urban context. The latter has led to brick and tile cladding, but with an intellectually elegant steel frame with carefully detailed and articulated connections.

The standard of the finished work is very high.

South Bank Tower, London

South Bank Tower

Architect
Kohn Pedersen Fox Associates

Structural Engineer
AKT II

Steelwork Contractor
Severfield

Main Contractor
Mace

Client
CIT Developments LLP

The transformation of this 1970s office scheme into a landmark structure was made possible through the use of innovative design solutions that are reliant on the use of structural steel.

The existing podium floorplates have been extended with two new floors added, whilst the podium building’s cores have been strategically relocated, opening out office space, promoting the ingress of natural light and encouraging a collaborative working environment. The use of a steel structure helped to minimise the loading onto existing foundations.

Within the tower the loadings from an additional 11 storeys of residential accommodation are carried through the extended core rather than the external columns, which had limited additional capacity. This was possible by hanging the new structure off the central core utilising a combination of a tension bar system and cantilevering steelwork in conjunction with lightweight concrete floor slabs.

Judges’ Comment

The re-use of a redundant concrete office block for upmarket residential accommodation, with extension upwards and horizontally, led to enormous structural complexity. The merits of steelwork enable a great increase in the number of storeys, in spite of the foundation constraints.

The team worked well together to meet the tight programme and satisfy the planners and the client.

Whyke Horizon Footbridge, Chichester

Whyke Horizon Footbridge

Architect
WilkinsonEyre

Structural Engineer
Balfour Beatty Mott MacDonald

Steelwork Contractor
Mabey Bridge Ltd

Main Contractor
Interserve Construction Ltd

Client
Highways England

The structure is a steel hybrid box girder/half- through trough. This efficient structural form gives both excellent torsional rigidity and allows the bridge to have a low overall structural depth.

The structure tapers over its length, with greatest depth at mid-span and minimal depth at each end. This form provides the structural depth where it is needed the most in the simply supported span.

Visually, the gently curved, sculpted exterior form is deliberately understated with a simple uncluttered exterior. Internal steel stiffeners define a series of gradually morphing skeletal ‘ribs’. These regularly spaced ‘ribs’, required to stiffen the cross section, constantly change shape as one travels across the bridge.

The main bridge was installed within an 8- hour night-time closure, with ramps and stairs being erected on subsequent nights to minimise disruption to the travelling public.

Judges’ Comment

Long approach ramps required complicated curved and twisted box spine beams leading to the main span. The elegant main span is formed of a cleverly shaped box section with upstand edge beams and neatly detailed post and mesh safety barriers providing a visually shallow profile.

The bridge provides a much needed safe pedestrian and cycle link across the busy A27 road.

Strabane Pedestrian and Cycle Bridge, Co Tyrone

Strabane Pedestrian and Cycle Bridge

Architect
WYG/Doran Consulting

Structural Engineer
AECOM

Steelwork Contractor
S H Structures Ltd

Main Contractor
Fox Contracts

Client
Derry City and Strabane District Council

This landmark cable-stayed bridge crossing the River Mourne provides a crucial missing link for pedestrians and cyclists between the residential areas and schools south of the river and Strabane centre to the north.

A key feature of the inclined and curved main pylon is a wishbone-shaped pair of Vierendeel trusses that stiffen the top of the arch in this zone of highly focussed loading.

The designed profile of the pylon legs was parabolic. This shape was approximated during fabrication by three constant radii, a discrepancy in geometry of less than 10mm, making fabrication of the pylon more efficient and cost-effective. Offsite fabrication produced a polished, precision-fabricated structure with the desired aesthetic qualities, as well as minimising site activities.

The installation of the mast required two large mobile cranes to safely carry out a critical and complex tandem lift.

Judges’ Comment

This bridge provides a key link between the town centre and the residential and sports areas to the south. The cable-stayed bridge cleverly cantilevers from the south side, minimising the impact of foundations on the north end with its busy roads and critical infrastructure services.

A striking steelwork project.

Information Age Gallery, The Science Museum, London

Information Age Gallery

Architect
Universal Design Studio

Structural Engineer
Heyne Tillett Steel

Steelwork Contractor
Ermine Engineering

Main Contractor
Parkeray

Client
The Science Museum

The key structural element in the new Information Age Gallery is a raised elliptical walkway which runs throughout the gallery and bridges the spaces in between six interactive ‘story boxed’ zones.

Primary support is provided via these steel- framed ‘story boxes’ and additional intermediate supports off existing columns, with seemingly invisible connections giving the illusion of the walkway piercing uninterruptedly through the pods.

The deck comprises a simple curved box ‘spine beam’ with regularly spaced cantilevering ‘ribs’ at either side, which was well equipped to handle torsion generated by the plan curves and eccentric column supports.

The walkway was delivered as a series of 6.2m long cassettes with the cantilevering ‘arms and glass balustrade supporting edge members pre- welded to the ‘spine’ offsite. These were lifted into position using spider cranes and connected via full strength butt welds.

Judges’ Comment

This imaginative design which achieves its supports from existing columns has been carefully detailed, assembled and installed into a highly constrained existing gallery space.

The merits of steelwork and the close collaboration between the designers, contractors and an informed client have all contributed to success.

Kiosk and Shelter, Bournemouth Pier Approach

Kiosk and Shelter

Architect
Poynton Bradbury Wynter Cole Architects Ltd

Structural Engineer
Hydrock

Steelwork Contractor
Weldrite Structures Ltd

Main Contractor
Willmott Dixon Construction Ltd

Client
Bournemouth Borough Council

The ‘leaf’ structures provide a visitor information centre and a shelter in the centre of Pier Approach on Bournemouth’s seafront.

Two identical structural forms were conceived – one open to provide shelter and performance space, the other enclosed by an elegant glass structure to create an information centre. Structurally a leaf is a natural cantilever, with a singular ‘stalk’ (cantilever box-girder column) supporting the ‘veins’ (cantilever beams) which reach out to support the surface (roof).

Structure is provided only where necessary. Not only does the structure taper down from root to tip, but the steel plate sections within each box-girder cantilever and reduce in thickness. This saves material and mass, resulting in a highly efficient construction. In addition, a discrete cantilever prop was added to the kiosk in order to further reduce the work required by the cantilever and its foundations.

Judges’ Comment

Two cantilevered leaf-form canopies focus attention on the pier approach. One provides welcome shade to the public whilst the other has been enclosed for a tourist office.

The steelwork is neatly made and provides models for further regeneration of Bournemouth’s seafront.