STRUCTURES
Steel constructions for high-rise buildings 1
Europe’s most experienced steel constructor With 90 years of experience, the Dutch company Hollandia has earned a reputation in steel construction for taking on the biggest challenges. Projects that other contractors consider too risky are seen as an opportunity for Hollandia to demonstrate its capabilities. Our engineers, tradesmen and construction management take steel into uncharted territory, pushing the boundaries beyond what was previously thought possible in steel construction.
‘Since 1992, Hollandia has been changing the London Skyline with 16 iconic high rise projects. The steel constructions have a combined weight of 106.200 tonnes. (including ‘Newfoundland’ and ‘Can of Ham’).’
Rabotoren, Utrecht
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ING House, Amsterdam
Petrochemical installations Hollandia has constructed some of the most challenging and complex projects for leading lue chip companies such as Shell, BP, Exxon and many others. Innovative strategies for prefabrication and logistics minimize site construction time whilst maintaining the industry’s highest quality and safety standards. Utility buildings Hollandia boasts an impressive portfolio, including world famous landmarks. Hollandia offers the complete scope for design supply and installation of: - Steel construction with fireproof coating - Service infrastructure in prefabricated modules - Floor, roof and facade systems
De Brug, Rotterdam
33 King William Street, London
Competing with the top Hollandia Structures has won numerous international awards, the most recent include: 2017: Whitechapel Station 2017: BIM award Holmestrand train station Norway 2016: Dutch National Steel Award IJSEI, Amsterdam 2014: BREEAM excellence Lely office Maassluis The Netherlands 2013: Excellence on Safety and Execution Exxon Mobile Rotterdam
Broadgate Exchange House
Haagse Poort
Unmatched expertise in complex projects Hollandia Structures has developed a solid expertise in the fabrication of steel structures that present huge challenges and associated risks. Our experienced engineers, technicians and management devise - unique & sometimes unconventional - solutions to the challenges presented. Dutch mentality The culture at Hollandia is one of continuous performance improvement. Our dedicated and stable workforce demonstrates flexibility and creativity to find solutions to minimize programmes and ensure deadlines are maintained.
‘The financial stakes are high, demanding construction work to take place in the shortest possible time.’
Architectural and geometric complexity Hollandia finds solutions to realise designs that are pushing the boundaries of engineering and construction. Fast-track schedule Construction elements are preassembled in the factory to minimize construction time on site. Logistics and planning Each component can be delivered at exactly the right time to any place in the world. Environmental restrictions Innovative planning and flexible labour strategies allow scheduling of the construction work to minimize any negative influences on local traffic, amenities or the environment. Compliance and certification Hollandia has LEED BREEAM certification and has committed to lower the environmental impact of the construction process.
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High rises at Canary Wharf constructed by Hollandia
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Steel: the construction material of the future Together with developers and architects, Hollandia engineers solutions to create the most cost-effective structures without compromising the vision for the building. Choosing the right materials is essential to find the perfect balance in design and cost gains.
‘Steel is the material of choice that maximizes architectural freedom and enables an earlier return of invested capital.’
Steel buildings are rapid to construct, of high quality, flexible and adaptable in application, and energy efficient in use. Steel frames can be delivered to a building site in large pre-fabricated assemblies. This is a solution for projects in dense urban areas that demand a high speed of construction with limited storage space for materials.
Saving weight Up to 30% lower foundation loads. Saving space Lower floors require slimmer support structures. The integration of services in the structural zone leads to reduction of 100 to 300mm in floor to floor zone and hence to savings in cladding cost. Saving time Less preparation time prior to construction 20-30% reduction of on-site construction time with minimal delay during winter construction. Form freedom Endless architectural expression possibilities. Increased flexibility Long span steel construction provides more flexible use of space.
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Newfoundland
Main contractor: Canary Wharf Contractors Client: Canary Wharf Group Floors: 61 Height: 220 meters Completion date: Q4 2018 Short construction period 10.000 tons of steel construction parts Each delivered at exactly the right time Located in the financial heart of London Constructing the 61-storey residential tower ‘Newfoundland’ is a challenging project. The building site is located at the western end of the Canary Wharf Estate, bound by a dock on one side and three busy roads on the others, leaving no space for storage of construction materials. Building a tower under these circumstances demands excellent cooperation between the different trade contractors along with excellent logistics and planning.
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The narrow footprint of the site posed a unique engineering challenge. Support columns for buildings of this size are usually large in cross sectional area, reducing the net lettable area. But in this case, weight distribution was even more important because of the unique ground conditions: the tower is constructed directly above the Jubilee line tunnels. These limitations largely influenced the design of the building.
The steel exo-skeleton structure provides 90 percent of the structural support. The load is transferred to the ground through its visually striking diagrid structure. At the bottom of the tower the mega grid distributes the load evenly between and on either side of the Jubilee line tunnels.
Hollandia is responsible for the detail design, fabrication, transport and erection of this unique steel structure. They also engineered a solution to continuously support the relatively light concrete core during the construction process: an innovative way of constructing the steel frame four floors at a time.
The diagrid consists of diagonal steel beams over the entire height of the building, forming a diagrid structure. The steel beams connect every four floors to form half a diamond. Here the outer frame is connected to the core via nodes and a precast concrete floor. While posttensioned concrete floors are installed on the three intermittent levels, the following four levels of steel diagrid structure is erected.
‘When completed Newfoundland will offer its residents breathtaking views over London.’
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30 St Mary Axe
Main contractor: Skanska Client: Swiss Re Floors: 40 Height: 180 meters Diameter: 50 meters Completion date: 2002 One year construction period 10.000 tons of steel construction parts Location: City of London Better known as ‘the Gherkin’ due to its distinctive pickle-like shape, the 40-storey glass-and-steel structure designed by Norman Foster transformed London’s skyline. With its circular plan of varying size and spiralling light-wells, the design of 30 St. Mary Axe is an architectural marvel. The construction of the steel structure required a special approach that had never been seen before.
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The building had to be constructed in a record breaking period. The construction site lies at the heart of the City’s insurance district. This posed limitations in accessibility.
A balanced diagrid structure is formed by a pattern of columns spiraling in both directions. At two-storey intervals the spirals intersect at 360 specially designed ‘nodes’. The heart of each node consists of a solid block of steel of 240mm by 140mm. This connection transfers the loads, both vertically and horizontally. The columns between the nodes are straight, with a change in direction and orientation at each node. As a result significant horizontal forces arise at these points. These forces are contained by perimeter hoops at each node level.
Due to the increasing weight of the structure, the buildings’ overall height decreases by eight centimetres. The construction expands laterally and therefore the hoops around the structure are pre-tensioned. The connection between the nodes and the radial beams had to be flexible to cope with changing forces during the construction process. These flexible hinges were locked after construction was finished.
The erection sequence progressed in two-storey bands in the following sequence: 1. Erection of steel core including access stairs and temporary bracing 2. Decking of core structure 3. Erection of diagrid columns and nodes as A-frames (pre-assembled at ground level) 4. Installation of radial beams and horizontal beams to complete the diagrid 5. Floor framing and decking 6. Floor concrete
‘The diagrid structure is a series of triangles that combine gravity and lateral support into one, making the construction stiff, efficient, and lighter than a traditional high rise steel construction.’ The diagrid steel structure provides excellent stiffness and stability for the tower, bearing a large proportion of the wind forces and gravitational loads. This reducing the loads on the foundation compared to buildings that are stiffened by a core. Thanks to this steel exo skeleton structure, the buildings interior is free of columns and is flexible in use, providing maximum lettable area.
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Kennedy tower Client: OntwikkelingsCombinatie Eindhoven Floors: 22 Height: 85 meters Completion: October 2003 Unique construction design 2.500 tons of steel construction parts Location: Centre of Eindhoven The Kennedy Tower in the centre of Eindhoven is a landmark for the city. The 22-storey tower is made of steel and glass, giving it a transparent and open character. The floorplan has a parallelogram shape to merge with the street plan. An unusual aspect is the fact that the lower part of the building is more narrow than the top of the building. This large expansion of the floors on one side of the building was an engineering challenge. The original solution was to support this by a massive concrete core. This core construction would have used 63 square meters of every floor and as a result the building would lose its transparent character.
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A brainstorming session with the architect lead to an innovative solution: An open steel supporting frame in the central area with columns and diagonal struts. Outside the core structure, the diagonals extended as legs (or sloping columns) to the outer wall, resulting in a repetitive Y-shaped steel construction in cross-section. The angled legs reach the outer wall at a level which is three levels higher than that of the starting point in the core.
In this way, clusters develop in the tower three floors at a time. One ‘Y’ covers two of these blocks - that is, six floors. The bottom three of these floors are resting on the lower diagonal, while the upper three floors are hanging on the diagonal strut. Much attention went into designing the nodes, since most of these elements would remain visible in the interior.
A major challenge to this type of construction is fire-resistance. Treating of the struts and columns with vermiculite was not an option since the architect attached much value to aesthetic quality of the steel and the construction, as part of the interior experience. After researching many different fireproofing methods the choice was made to coat the steel with fire-resistant paint. This option ultimately proved to be one of the most economical solutions.
‘During preparation as well as during construction, Hollandia has demonstrated excellence in construction and ensured the high quality of the end result. We look back with great satisfaction to the construction of this tower and our partnership with Hollandia.’ Project manager OntwikkelingsCombinatie Eindhoven
The Kennedy tower was erected in a short period of time thanks to intensive coordination between design, fabrication and assembly. The steel structure was pre-assembled at the factory and transported to the construction site in clusters of three storey’s.
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STRUCTURES Visiting address Markweg Zuid 1c 4794 SN Heijningen Correspondence address Hollandia Structures BV P.O. Box 11 4793 ZG Fijnaart T: +31 (0) 167 527 100 E: info@hollandiastructures.nl I: www.hollandiastructures.nl