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Tower safe for 300 years: experts
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ITALY'S famous Leaning Tower of Pisa came a step closer to reopening on Saturday when it was officially handed back to the city after 11 years of work to prevent it from toppling over, with experts' prediction that the tower would be safe for 300 years.
Despite the restoration, tourists will have to wait at least five months before safety barriers are put in place to let them climb it once again.
The 12th-century tower, one of Italy's most famous sights, was closed in 1990 because its leaning had increased to the point of becoming unsafe.
The lean has been reduced by 43 centimetres at the top of the tower, returning the tilt to 4.11 metres — the same as that measured at the start of the 19th century.
A team of international specialists succeeded in pulling the tower back by slowly siphoning sand from under the north side of the tower. The tower leans toward the south.
Experts say the work on the 56-metre-high tower, which stands beside Pisa's cathedral, means it should be safe for the next 300 years.
The tilt had been increasing by about one or two millimetres a year as soft clay under the southern side of the tower gave way at a faster rate than ground under the northern side.
The subsidence was exerting intense pressure on the tower's second story and it was feared the structure would collapse.
It took the “lean-team”, led by University of Turin Professor Michele Jamiolkowski, five years of trial and error until a solution was found.
The tower was steadied temporarily with steel cables, and lead weights were placed on its foundation. Then drilling was started to gradually remove soil in bucket-size quantities from under the higher, northern side of the tower.
The difference is barely visible to the human eye, still leaving the tower with a hefty lean.
(SD-Agencies)
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