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According to the case study, The Gateshead Millennium Bridge is one of the landmark structures in Newcastle which was awarded over 20 design and 5 lighting awards and was the world first vertically rotating bridge. It was also named as "The Winking Eye".
The Gateshead Metropolitan Borough Council was decided to build a foot-bridge for pedestrians and cyclists across Newcastle and Gateshead in order to connect the newest venues such as Sage and BALTIC centre for contemporary Art and also be part of the redevelopment of Gateshead Quayside. The design of the bridge has a parabolic steel arch spanning 105m between end supports and rising 45m above river level. The arch is kite-shaped in section tapering in both plan and elevation. The arch is fabricated from steel plate and stiffened both longitudinally and transversely. The section is fully sealed by welding
The overall construction cost was £22m. The bridge is 126 metres long stretch across the River Tyne and the Arch is 50 metres height when in upright position.
Gifford & Partners and Wilkinson Eyre Architects won the design competition in February 1997. (K. Butterworth, 2003). In 1998 the Watson Steel was appointed as a sub contractor to operate with the other main contractor Harbour & General. All the bridge sections were fabricated at Watson Steel, their package was the fabrication, assembly and erection of the bridge structure.
The section then transported from to the AMEC works in Wallsend, Newcastle. They welded the sections together and painted the bridge with a weather prove paint. In 2000, the bridge was completed and ready to lift into place, the bridge was transported six miles up the river to the site by using one of the world's largest floating cranes. It was opened to public in Sept 2001 and was dedicated by Queen Elizabeth II in May 2002
Fabricating and installing of the Bridge
Gifford Graham & Partner
Wilkinson Eyre Architects
Harbour & General and Volker Stevin
Steel Construction Specialist
Watson Steel Ltd.
Cable steel supplier
Bridon International (suspenders)
The Gateshead Metropolitan Borough Council
Construction on site started with the piling and cofferdam construction. At the foundation of the bridge, the end support comprises substantial reinforced concrete structure in each supported, attached by 14 bored casts-in situ piles (1.5m diameter). These piles jacked about 20m below ground level in the coal, lying beneath riverbed gravels and glacial till.
Fabrication at Hadrian's Yard started with each of the nine arch segments being welded together with the arch lying flat on an accurately aligned support system. The rest of the components such as Paddles, trunnion shafts, bearings and pedestals were installed and the arch was carefully raised on its permanent bearings and temporarily supported from a vertical guyed prop in order to minimise access requirements at height. The cable were attached to the arch. The torsion box and deck sections were then set out beneath, welded together and the bases installed. Once the installation was completed, the bridge was prepared for lifting
Suspending the whole bridge from hangers attached to each end of the trunnion shaft, suspended from a trussed lifting beam. An adjustable tie was installed between each side of the bridge to control the lateral spread of the arch.
The whole bridge was fitted precisely between the quay walls onto its supports and lowered into place by the world's largest floating cranes.
The whole construction period was lasted for two year.
Function of the bridge :
The concept of double-arch structure, the whole bridge from rotating about a pivot point mounted on each end support in order to provide the necessary shipping clearances.
The bridge is driven by six horizontally mounted double-acting hydraulic cylinders, three in each end support, are used to open the bridge, the total movement time of the bridge is approximately 4 minutes. The cylinder anchored into the massive concrete sub-structure, thrust against the toe of the paddle, forcing the whole structure to rotate in an angle of 40°. When operating, the centre of mass of the whole structure moves across the pivot point, the load change from a compressive load to tensile load. When fully open the cables between arch and deck lie perfectly horizontal. The hydraulic pump is controlled by computer system to ensure no twist is induced into the structure.
To ensure the structure is functional and workable, an early stage included the behaviour due to wind and pedestrian condition and dynamic response has been carried out, the wind tunnel testing was carried out using both smooth and turbulent flows.
The dynamic analyses were undertaken to confirm the vertical response of the structure under pedestrian loading.
Sustainable: (compared with essay 1)
Sustainability has become an important part in construction the Gateshead Bridge, because due to the fact it is harming the environment and the purposes of sustainability are to produce a better quality for living. The purpose of sustainability is protecting the environment by using natural resources, and high maintenance.
In relation to this case study, the Gateshead Millennium Bridge sustainable development team was focused on satisfy the three main criteria - the "triple bottom line" as below:
Steel is the most suitable and sustainable construction material for the project as steel are non-toxic reusable, renewable, and recyclable, and choosing it for bridges represents a sustainable management of natural resources. Moreover it can be recycled repeatedly without losing any valuable properties plus it is very efficient. Furthermore, it is labour efficient especially it is using a precast method.
For the air and traffic pollution, the project have used the methods of prefabricating Steel instead of building in-situ; this will then reduces time of the building process and the carbon emissions that were produce by the vehicles travelling repetitively whilst the fuel for cars will be another factor. Also it will minimise the impact of construction on local communities as there is much less site traffic.
For reducing the noise pollution from the site, the project have specify some wall structure as sound shields to minimize the noise in case it disturbs the residents and people in the surrounding area.
In order to reduce the on-site works and the numbers of lifts, the subcontractor used a scheme called "lift-in-one scheme", which assembly at the fabrication facility would reduce the need for major works within the river together with consequential risks, minimise the impact of construction on local community. (John Johnson, 2003)
In relation to my case study 1, the tower bridge was not sustainable and efficiency
In essay 1, the bridge was built on site last for xxx years which is not sustainable and efficient
Society gains in many ways from the benefits delivered by steel bridge solutions. Landmark steel bridges that embody
good design, are economical, and quickly built, have stimulated regeneration of many former industrial, dock and canalside areas.
Disruption to road and railway users is minimised, if not eliminated, by taking advantage of the ability of steel bridges to be installed with minimal fuss. Offsite fabrication also means far fewer site visits from heavy vehicles, benefiting local communities. The typically rapid construction period for a steel bridge means that unavoidable impacts on local people and businesses will be as short as possible.
Steel bridges represent the superior option when health and safety is considered. Offsite fabrication means steel is safely manufactured in factory conditions. Automated production, using robotic welders for example, makes for safer working environments. Work on site is inherently safer, with far fewer trades and operatives involved and, because steel is speedily erected, less pressure of time.
This material is simply low in the embedded energy, and contains low carbon also it is durable and it was estimated that it can last for 100 years, therefore there will be less maintenance cost which will be very beneficial in the long term.
The bridge is using the precast method which the components are individually assembled, hence when the components of the bridge are not working properly it can reduce the maintenance cost; and possibly in the future, it can be easily extend.
Furthermore when there is a possibility that the bridge going to redeveloped in the future, the materials can be recycle, and because the structure frame is precast, it will be easier to remove which reduce the carbon footprint, the cost and the time during the building process and also creating environmental friendly environment.
Steel is recognised as the economical and most sustainable option for an increasingly wide range of bridges. Dominant in the long span and railway bridge markets, steel is now the choice for shorter span and highway structures as well.
Steel bridges represent an efficient use of resources and are readily adaptable to changing road configurations and increased loading, which would render other types of structure obsolete ahead of their original design lives. Bridge owners also increasingly value steel for its durability - a proven life span of at least 100 years - and low-maintenance advantages. Being inherently durable and lightweight compared to alternative materials helps make steel the most economical option, minimising substructure costs, especially in poor ground. Because of steel's minimum self-weight bridge sections are transported to site only when needed, and easily handled once there. Most work is carried out offsite resulting in shorter and more predictable construction programmes.
Steel bridges can also be assembled adjacent to their final location and quickly lifted into position, minimising the need for costly possessions of highways and railway track. The approach to bridge construction made possible by steel allows disruption to road and rail users to be kept to a minimum.
Protective, long-life coatings can easily be applied at the
fabrication plant. Use of weathering steel, which needs no
protective or other coatings, is increasingly popular, for aesthetic
reasons as well as minimising the need for future maintenance
and associated road closures. Steel bridges lend themselves to
easy and rapid strengthening or repair in the event of accidents,
with well proven techniques like heat straightening ensuring that
damaged structures are soon back in use.
High quality, defect-free structures are best assured by using
steel for bridges. Bridge owners have the reassurance that the
long term performance of a steel structure's elements is easily
assessed from visual inspection - there are no structural elements
hidden in ducts and other areas where visual inspection is not