Detail :: Data Jembatan
Jembatan Strait of Messina
Geography[edit]
The Strait of Messina is a funnel-shaped arm of sea that connects the Ionian Sea in the south to the Tyrrhenian Sea to the north. The width of the strait varies from a maximum of approximately 16 km (9.9 miles) (between Capo d'Alì in Sicily and Punta Pellaro in Calabria) to a minimum of approximately 3 km (1.9 miles) between Capo Peloro in Sicily and Torre Cavallo in Calabria.[4] A similar distance separates Pezzo and Ganzirri; at that point, the strait is only 72 m (236 ft) deep, while in other places it can reach 200 m (660 ft) deep. It is also characterised by strong currents.
History
The idea of a bridge crossing the strait is an old one. The Romans considered building a bridge joining Calabria and Sicily made of boats and barrels. Charlemagne considered joining the two sides with a series of bridges. This idea was revived by the Norman adventurer Robert Guiscard in the 11th century and by Roger II of Sicily in the 12th century.[citation needed] In 1876, Giuseppe Zanardelli was convinced that the strait could be linked by either a bridge or a tunnel. In 1866, public works minister Stefano Jacini gave Alfredo Cottrau, an internationally recognised engineer, the task of drawing up plans for a bridge between Calabria and Sicily. Later, in 1870, Navone proposed building a tunnel based on Napoleon's idea of a tunnel under the English Channel. This tunnel was to start at Contesse and was to pass below Messina and Ganzirri at a depth of 150 m, crossing the Strait to Punta Pezzo and resurfacing at Torre Cavallo.
A geologic study of the area of the Strait of Messina was published in 1909 (historical Arch. Sicilian year XXXIV f.1,2) and in 1921, a study of an undersea tunnel was released to the Geographic Conference of Florence. A group of railway civil engineers studied the possibility of a suspension bridge but nothing came of it. The idea was revived in 1953 by master bridge builder David B. Steinman with a plan to build a bridge that crossed the Strait using two 220 m (720 ft) towers sunk in 120 m (390 ft) deep waters. The proposed 1,524 m (5,000 ft) span would have represented a world record, eclipsing the then-longest 1,275 m (4,183 ft) centre span of the Golden Gate Bridge and beating the 2,256 m (7,402 ft) Mackinac Straits Bridge (then in planning) with a total length of 2,988 m (9,803 ft). The proposed structure would have cleared the sea by 50 m (160 ft) to allow shipping passage, and to have had two decks, the lower to carry two rail lines, and 7 m (23 ft) above, a road deck 30 m (98 ft) wide. The main cables would have been 1 m (39 in) diameter. The bridge would have required 12,000 workers and cost hundreds of billions of lire.
Early planning stages[edit]
- In the 1960s, a wide variety of ideas evolved with everything from submerged tubes to floating struts, pontoons and a revolving central section of the bridge. None turned out to be realistic.
- In 1969, an international design competition was arranged.
- In the 1970s, feasibility studies were undertaken by the State Railways leading to the creation of a private company with responsibility for planning the crossing of the Strait.
- In the 1980s, the Messina Strait Company (Stretto di Messina S.p.A.) was set up with support from the State Railways, the regions and IRI. It concluded that it would be feasible to build a suspension bridge.
- Detailed plans followed in the 1990s with final approval from the High Council of Public Works (Consiglio Superiore dei Lavori Pubblici).
Development of detailed plans
The 2006 plan called for a single-span suspension bridge with a central span of 3,300 m (10,800 ft). This would have made the span more than 60% longer than the Akashi-Kaikyo Bridge in Japan (the largest suspension bridge in the world at 1,991 m (6,532 ft).
Plans called for six traffic lanes (two driving lanes and one emergency lane in each direction), two railway tracks and two pedestrian lanes. In order to provide a minimum vertical clearance for navigation of 65 m (213 ft), the height of the two towers was to be 382.6 m (1,255 ft). This would have been taller than the Millau Viaduct in France (currently the tallest bridge in the world at 341 m (1,119 ft)). The bridge's suspension system would have relied on two pairs of steel cables, each with a diameter of 1.24 m (49 in) and a total length, between the anchor blocks, of 5,300 m (17,400 ft).
The design included 20.3 km (12.6 miles) of road links and 19.8 km (12.3 miles) of railway links to the bridge. On the mainland, the bridge was to connect to the new stretch of the Salerno-Reggio Calabria motorway (A3) and to the planned Naples-Reggio Calabria High-Speed railway line; on the Sicilian side, to the Messina-Catania (A18) and Messina-Palermo (A20) motorways as well as the new Messina railway station (to be built by Rete Ferroviaria Italiana).
Geographically, the bridge was planned to connect Reggio Calabria to Messina, the two cities which face each other on either side of the strait and form a single city. This ambitious urban project was called Area Metropolitana integrata dello Stretto (Integrated Metropolitan Area of the Strait) or simply Città dello Stretto (City of the Strait). Among the controversies surrounding the building of the bridge was strong opposition to the formation of the new city by various Sicilian nationalist groups.
A construction consortium led by Impregilo S.p.A. was chosen in 2005, with actual construction set to begin in the second half of 2006. The bridge was designed by Danisharchitects at Dissing+Weitling in close collaboration with the Danish engineering firm COWI.
On 27 March 2006, Impregilo and Stretto di Messina announced that they had signed a contract assigning final project planning to a General Contractor. Impregilo S.p.A., the lead partner had a 45% share. Other participants were Spain’s Sacyr S.A. (18.70%), the Italian companies Società Italiana per Condotte D’Acqua S.p.A. (15%) and Cooperativa Muratori & Cementisti-C.M.C. of Ravenna (13%), Japan’s Ishikawajima-Harima Heavy Industries Co. Ltd. (6.30%), and Consorzio Stabile A.C.I. S.c.p.a (2%). The General Contractor would also be assisted by the Danish and Canadian companies COWI A/S, Sund & Baelt A/S and Buckland & Taylor Ltd., who would handle project engineering. Completion was projected to take six years, at a projected cost of €3.9 billion. The first task of the General Contractor was to draw up the final project.[5]
On 12 October 2006, the Italian Parliament voted 272 to 232 in favour of abandoning the plan due to the bridge's "doubtful usefulness and viability," as well as the inability of the already burdened Italian treasury to bear its share of the cost. Additionally, transport minister Alessandro Bianchi pointed out that the road and rail links leading to the location of the proposed bridge are not capable of supporting enough traffic to make the bridge profitable. Other reasons for abandoning the plan were earthquake risk, and fears that much of the funds would be diverted to the criminal organisations Cosa Nostra and Ndrangheta.
Sumber :
http://en.wikipedia.org/wiki/Strait_of_Messina_Bridge
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