Special report:
Three Gorges Project
THREE GORGES DAM SITE, Hubei Province, June 5
(Xinhua) -- Measures have been taken to keep the just-completed main wall of the
Three Gorges Dam, the world's largest, safe and sound against the demolition of
the project's last cofferdam, which is due for Tuesday afternoon.
Yu Ying, a technical expert with the Gezhouba Dam
Group that is accountable for the demolition effort, said the main dam can stand
the shock the blast would produce.
The demolition will be operated by segments and will
make fragments of the cofferdam tumble upstream like building bricks, according
to Yu.
Two arrays of "bubble curtains", resembling
air-filled bags for the protection of drivers and passengers in car accidents,
will beset to absorb tremendous shock waves and surge pressure from the blast,
in a bid to reduce their energy by 50 to 70 percent before they arrive at the
main dam, Yu explained.
The cofferdam, with its southern connection section
joining the main dam, is measured 580 meters long, 140 meters in maximum height
and eight meters in top width. The upper 30 meters of it, involving nearly
180,000 cubic meters of concrete, will be removed by using 192 tons of dynamite,
with the under-water part of 110 meters in height to be retained as a protective
structure for the main dam.
After the demolition, the main dam will formally
begin holding water and contribute to flood control. Enditem