Cofferdam Removal of the Second Powerhouse of Abbaspour Dam

lifegunbarrelcityUrban and Civil

Nov 26, 2013 (3 years and 8 months ago)

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Cofferdam Removal

of the Second Powerhouse of Abbaspour Dam



M.Moradi (Manager Deputy

JAHAD TOSSE MANABE AB

Co.
)

A.P.Ruhi (Technical Office Expert

JAHAD TOSSE MANABE AB

Co.
)



Abstract

The

s
econd
p
owerhouse of Abbaspour
d
am has been constructed with an i
nstalled
capacity of 1000 MW.

Two

conic shaped

concrete cofferdams
were

constructed to
prevent water
flowing into

the powerhouse

during construction period
.

Each
cofferdam had

20 rings.

A
fter

the
construction of

the

powerhouse was completed, two
sequential

methods were

finally

used to
remove

the cofferdams:

Demolishing

by
dynamite explosion in each cofferdam ring, 60 holes were hollowed out.
After
explosion

the concrete
was

removed easily by hand tools.

To
control hurled materials
arising from explosion, a
platform was built around the cofferdams
and

the
platform

was cleaned by use of a tower

cr
a
n
e
.


Removing the cofferdam by using

a barge
, on which a beam is placed. When the
barge
was

rested on the cofferdam, the tanks
were

filled with water
and

the barge
s
ank
blow

the surface of the water. After that the beam fixed to the con
crete ring by using
three jaws. T
he

fixed concrete ring c
ould

easily be removed by only letting the water
out of the tanks. The barge
rises

now to a higher level and separates the ring
from the
cofferdam. Finally a tugboat is used for
taking

the barge to the
upstream of the
reservoir
to unload the rings.