Immersed Tunnel in High-Sea
Smart paint could revolutionize structural safety
Immersed Tunnel in High-Sea Smart paint could revolutionize structural safety
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Immersed Tunnel in High-Sea Concrete Building Block Placed in the First HighImmersed Tunnel Sea World in Corea La construction began in 2005, with two cable-stayed bridges with main spans of 475 meters and 230 meters long underwater tunnel with a length of 3.2 kilometers, which will ultimately form part of the new highway connection between Busan and Geoje Island Island, located at the southern end of the Korean peninsula, with a length of 8.2 kilometers. When finished execution, the new four-lane highway on a combination of bridge and immersed tunnel will connect the city of Busan, the second largest city in South Korea, with the island of Geoje, the second largest island and a site famous for its beaches, forests and mountains and for its industrial activities such as shipbuilding, heavy industry and marinos. Como crops is already a favorite destination for South Koreans tourists, Busan-Geoje connection will ensure easier access to region. The new connection will reduce the journey time to just under an hour, encouraging the development of tourism and allowing marine aquaculture producers transport their goods efficiently, road, markets located on the mainland. Currently, trips are undertaken by ferry or through a circular route of bridges and roads.
The end of the project is scheduled for December Danish company COWI 2010.La is the lead consultant on the bridge and tunnel project, divided into two contracts. For the tunnel COWI has been associated with Daewoo Engineering. The client, Daewoo Construction and Engineering (E & C), has joined the bulk of its organization and more than 200 consultants in Busan, where they work in a logistics project on a large scale, a version of the smaller project of building the connection between Denmark and Sweden across the Oresund Strait. Click kk/22. Visit www.dwconst.co.kr and www.cowi.dk Dutch company Halcrow and Tunnel Engineering Consultants (TEC) are the technical advisers of Daewoo Construction, led a consortium which was awarded the contract of U.S. $ 1,100 million for the design, construction and operation of the Busan-Geoje connection. Mott MacDonald has been appointed to assist Yooshin Engineering Corporation in the supervision of works
Difficult to design and build on the seabed clay bland. The tunnel, comprising concrete elements 18 with a length of 180 meters and each element formed by eight segments of 22.5 meters long, is placed in a trench to a depth of dredged 48 meters and then tapa. Since the standpoint of international consulting team responsible for design and construction management of the world's first underwater tunnel in the open sea, built in deep water, had to take into account new methods for working in a wave 11 meters higher than the Oresund Strait, a sea floor with the consistency of butter and a high risk of earthquakes. The task was particularly complicated in terms of soil mechanics, hydraulics and design of manufacturing tunnel
The rectangular concrete drawer is running. The project is progressing in good condition and the first set of four elements of the immersed tunnel, each with a length of 180 meters; leave the dry dock in September. Immersion of this first package is scheduled for later this year. There are also short tunnels in rock, which form part of project .Al same time, running the foundation of the two cable-stayed bridges, which are on the same connection by motorway. The bridges are designed to withstand wind gusts up to the force of a typhoon and run with large precast ocean. La taken to highway construction in open sea occurs in completely different conditions than on the ground. Calculations have been carried detail to know exactly what conditions you can work on open sea, which have shown that the machinery cannot be used if the wave height is higher at 40-60 cm.
There are a number of challenges in building the tunnel submerged in a pattern devised for smaller depths. One of them is represented by the soft clay seabed, which are not consolidated during the ice ages, as in Denmark. The soft means a greater risk of developing significant seats and hence deformation of the joints between elements, which also have to withstand water pressures of over 50 meters. It was necessary to review the current design of joints and methods to strengthen the field. The land must be strengthened to avoid bearing capacity, seats and stability. Also, there have been sophisticated analysis of earthquakes, to know the movements of the joints and the stability of the elements of tunnel. Finally, there have been studies on scale models to determine the degree of disorder on the tunnel extremely high waves, both during construction and after the waters prefunds Daewoo execution
Impermeability Engineering and Construction has the task of achieving simultaneously the challenges of a particular environment hostile and very strict technical specifications to implement the project. The challenges associated with a project of this magnitude are immense. One of the most important so far was to ensure the tightness of joints tunnel. For run the job, Daewoo E & C Trelleborg Bakker invited to provide injectable waterproofing gaskets and Omega, one of the largest orders in company history. Although injectable Trelleborg joints waterproof the joints between the concrete elements, forcing through the injection pipes installed every four meters, the sponge rubber of the ends of the boards is compressed, creating a channel which is filled with fluid injection to seal cracks, ensuring waterproofing.
For the location of the tunnel in an area of seismic risk, some of injecting joints are secured with a secondary seal Omega. Trelleborg Bakker provides Omega seal 1.2 kilometers, 1.87 kilometers of secondary Omega boards and nine miles of injecting together for this experience project. The Trelleborg seals for tunnels means that you can quickly find a solution to ensure the success of long-term performance. Other tunnels were equipped by Trelleborg to depths of 25 meters. This tunnel is about 50 meters, making it necessary to implement new tests on the joints to get the parameters of the technical specifications. The immersed tunnel section connecting BusanGeoje is for these reasons, an excellent opportunity for the company to strengthen its reputation as a world leader in polymer-based solutions for the civil works
Smart paint could revolutionize structural safety The green paint uses nanotechnology to detect the movement of large structures, and could shape the future of security surveillance. Traditional methods of evaluation of large structures are complex, time and the use of expensive instruments, with spiraling costs in millions of pounds each year. However, the smart paint costs only a fraction of the cost and can be simply sprayed on any surface electrodes to detect structural damage long before failure occurs.
Dr. Mohamed Saafi, University Department of Civil Engineering, said: "The development of this technology smart paint could have important implications for how to ensure the safety of large structures around the world. "There are no limitations as to where they can be used and the nature of low-cost offers a significant advantage over current options available in the industry. The production process and the paint application also gives you an advantage as no requires experience and supervision itself is simple. " The paint is obtained using a recycled waste product known as fly ash and highly aligned carbon nanotubes. When mixture has a cement-like property that makes it especially useful in harsh environments.
Dr. Saafi said: "The monitoring process involves in effect a wireless sensor network. Paint is connected to the wireless communication nodes harvest energy and alertness to detect . remotely any invisible damage such as micro -cracks in a foundation of concrete wind turbines. "Foundations of wind turbines are currently being monitored through visual inspection. Paint developed with wireless monitoring system could significantly reduce maintenance costs and improve the safety of these large structures. "The current technology is limited to look at specific areas of a structure at a given moment, however, the smart paint covers the entire structure which is particularly useful to maximize the opportunity to prevent significant damage."
The research was conducted in Strathclyde with Dr. Saafi working with David McGahon, who began work as part of his doctoral thesis. With fly ash is the main material used to make paint, which costs only percent of an alternative screening methods widely used. A prototype has been developed and tests have shown that the paint is highly effective. More tests are expected to be held in Glasgow in the near future
Just as there was talk of sensors in buildings and other structures, now a Canadian company announced the creation of a monitoring system to detect corrosion of reinforcing steel in reinforced concrete elements called SensCore who works as a wireless sensor network and other equipment to channel their information to a central database to which only staff can access authorized. The sensors measure different parameters in the reinforcement of concrete such as moisture at different locations and depths of the monitored element, existing corrosion and performance hidrof贸bicos .The coatings system has been developed jointly with the Swiss University and is being tested in various structures proving a good adaptability to same.