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MARCH-APRIL 2014
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EXPLOSIVE
DEMOLITION
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result in obvious problems, potential damage,
and complaints that would generate a large
amount of negative publicity.
FLOWER POWER
Special attention was given to the flower
shop that was next to the building. The more
sensitive and the more expensive flowers
were transported to a field 1 km (0.6 miles)
away from the site. For flowers that were not
transported to the field, a canvas cover was
erected three hours before the implosion
and removed immediately after, carried out
sleepers were used to anchor the transmission
poles in the street that served to contain the
spread of material from the implosion. Given
that the distance was less than 2 m (6.6 ft) in
some instances, the plan was to protect the
pole due to possible scattering.
Power to the high voltage cables was
turned off minutes before the implosion
and the cable connections were protected by
wooden boxes. If these connections or cables
were damaged, the power company estimated
that there would be a period of two hours
without light across the city, which would
O
n November 2, 2012, Fabio Bruno
Pinto safely performed the implosion
of three reinforced concrete buildings
with 7, 6 and 5 storeys respectively in the
city of Niterói in Brazil. The buildings
belonged to the former Santa Monica Hospital
that had been out of use for over 10 years.
There were many elements that needed to be
studied and eliminated during the implosion.
The close proximity of other buildings,
energy cables and structures on all sides of
the subject structure raised considerable
concern prior to the implosion.
To the right there was a road with houses
along its entire length at a maximum distance
of 10 m (32.8 ft) from the edge of the
buildings. There was also a power grid on
the pavement just 2 m (6.6 ft) away that has
to be protected and remain undamaged
because it serves a population of
approximately 15,000 people.
To the left there were high voltage cables
only 8 m (26.5 ft) away that supplied much
of the entire city of Niterói, which has more
than 500,000 residents. In addition a flower
shop abutted the wall of the building, and
all plants were exposed in the open. The
preservation of this flower shop was a new
challenge. Added to that, the reinforced
concrete water tank of one of the buildings
was positioned to this side.
To the front was the the busiest street in
Niterói, the Marques do Paraná Avenue. The
street was 7 m (30 ft) away from the first of
the three buildings and because of the slope,
there was a substantial risk that debris would
fall into this street following the implosion.
METHODOLOGY
As work began on October 01st 2012, the
three buildings were soft
stripped, generating a
volume of 96 m³ of timber,
which was donated and
transported to the nearest
ceramic factory. This was
done to allow the implosion
of the buildings to be carried
out without contamination
of the resulting debris, which
was going to be crushed and
recyled. To guard against the
possibility of flying debris,
six layers of highly resistant
screens were positioned to
screen every floor where
there was going to be a
detonation.
The implosion sequence of the columns
was designed according to the results of a
simulation developed by Applied Science
International (ASI). The design concept was
to make sure that the implosion happened
towards the centre of the building rather than
towards the edges. To achieve this, several
scenarios were studied to decide which
columns were to be loaded with explosives
and which should be left uncharged, as well as
the exact delay and sequence of the implosion
of the columns.
To protect the street power grid, railway
Inner
city
blast
Three major
blowdowns were
shortlisted for last
year’s Explosive
Demolition Award.
D&Ri
reports first on
the eventual winner,
Fabio Bruno Pinto’s triple
blowdown in Niterói, Brazil
