Boadilla Tunnel AUTOVÍA DE CIRCUNVALACIÓN WITH FALSE TÚNNEL MADRID, SPAIN – 2004
Tunnels and structural elements
Madrid is immersed in a big infrastructure project to get better its access and internal transport. The big grown of its population, and the increase of traffic, have produced the necessity of the construction of a third ring road to Madrid, 25 kilometers from the center, besides radial motorways to make easier the access to the city. In the section of M-50, that goes from A-5 to A-6 motorways was necessary the construction of a false tunnel, 500 m long and 19 m diameter. After the concrete frame of the false tunnel was finished, and starting the filling with soil, important structural troubles were detected because of using a wrong construction process. With these proceeding, and being necessary the reconstruction of the tunnel at the same time that the traffic was going to begin, it was essential the use of a light expanded clay filling of Arlita, that allowed solving the trouble by lightness, fast installation and easy handling. Supply of Arlita was transported principally with 80 m3 dumping trucks that allowed spreading Arlita more than 3.200 m3 per day. Spreading and compaction made with 2 bulldozers, by using layers of 1 m and 4-5 passes, permits an easy, fast and efficient work. When the Arlita filling will finish, a soil layer and an organic soil layer will spread to replant the woodland.
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SPAIN TECHNICAL DATE OF THE PROJECT Designer: ALEPH Consultores. Contractor: Radiales UTE. (ACS, FCC, OHL y SACYR) Place of job: Spain - Madrid - M50. Date of application: 2004. Quantity: 100.000 m3. Type of material: Arlita 0-30 mm (dry density of 350 Âą 50 kg/m3). Time table: from January 2004 till June 2004. Others: Max thickness = 5,80m.
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