Download Major diamond demolition in Moscow

Construction
Major diamond
demolition
in Moscow
The post Communist era in Russia has
been around for some time now so it is
not surprising to hear of major diamond
demolition works being carried out
there. This report by Andrei Bushmarin
describes the controlled demolition,
using diamond wall saws and wire saws,
of a 9-storey building. Major restraining
factors were the proximity of nearby
buildings and a tight time schedule.
ast year, Russian company, ZAO
Olvex broke new grounds in the
field of diamond wire-sawing when it
undertook the demolition project of a
half-constructed 9-storey building which
was part of the second phase of a
building project in Moscow known as
the ‘World Trade Centre’ (also referred to
as WTC-2). The first phase of WTC (also
known as WTC-1) comprises the existing
Mezhdunarodnaya hotel, together with a
few high-rise buildings and parking lots.
Originally, the second phase of WTC
involved the construction of a high-rise
building which would house hotel and
office facilities. Its construction
commenced in 1992 and was put on hold
in 1998, leaving the nine-floor building
uncompleted. Finally, in 2004, a decision
was taken to demolish it.
Located on the same bank of the Moscow
River and just a few hundred meters
away from another major development
known as the ‘Moscow-city’ project,
WTC-2 was thought to become a classic
example of the Soviet-Era architecture.
However, the ongoing process of the city
renovation has entailed its demolition,
with an ultra-modern 20-storey 4-star hotel
and 30-storey business centre being built
on its place. The total value of the WTC-2
project amounts to some US$100 million,
thus making it one of the most significant
and ambitious construction programs
currently under way in the Russian capital.
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Fig 1 View of the 9-storey building half way through the demolition
Demolition of the building
above-ground
Demolition of the building
below ground
By the end of 2005, ZAO OLVEX had
demolished some 55,000 m3 out of a
100,000 m3 building volume using diamond
cutting technologies. The total volume of
reinforced concrete blocks removed by
the main contractor, AOA Usabda-Center
was some 26,500 tons or approximately
10,500 m3. Of this, the ZAO Olvex operation
accounted for some 14,500 tons or 5,800 m3.
It took 60 operators 2 months to complete
the job using 20 diamond wall saws
(Figs 1 and 2).
Technically, this job posed no difficulties
to Olvex operators - slabs were just 25 cm
thick, with column thicknesses varying
from 40 to 50 cm. The major issue on this
job was that the WTC-2 had been erected
in immediate proximity to a functioning
building, with its outer wall being just a
5 cm away from the other building.
It was impressive performance of Olvex
during Phase I that played a crucial part
in awarding a contract for the demolition
of the WTC-2 underground facilities to
the St. Petersburg-based company. The
main contractor set a task to cut a 2 m thick
foundation slab made from cast-in-situ
reinforced concrete, with a total volume
of 1,640 m3, into 20 t blocks. Underneath
this slab, there were reinforced concrete
diaphragm walls going down to a depth
of 16 m. As their exact location was
unknown, the complete removal of the
2 m thick foundation was out of the
question. Since the lateral sides of the
slab were totally inaccessible, operators
had to cut it in both horizontal and vertical
planes using diamond wire saws while
advancing from the centre to the
periphery (Fig 3).
INDUSTRIAL DIAMOND REVIEW
1/07
Construction
According to the job specification,
horizontal cuts were to be made along
the total area of the slab to a depth of
1.8 m, i.e. 20 cm short of its total depth.
When the job was completed, a 20 cm
thick reinforced concrete slab, with a total
area of 820 m2 was left intact, together
with the reinforced concrete diaphragm
walls. The main contractor finished the
demolition of the remaining structure
using hydro-electric jackhammers in a
phased manner.
One of the major problems Olvex
operators were confronted with on
this stage of the works was to prevent
the ground beneath the adjacent
Mezhdunarodnaya hotel from moving.
To this end, the main contractor drove
hundreds of 30 cm diameter metal piles
into the ground at a depth of 10 m prior
to the commencement of work.
When dismantling WTC-2, ZAO Olvex
cut around 6,000 m2 of reinforced concrete
in total. Of this some 820 m2 was cut
using horizontal wire sawing, which the
company feels must be some sort of
record for this type of sawing.
Horizontal wire sawing
innovations
Horizontal sawing is known to be a very
tricky operation, especially if there is no
access to lateral sides of a concrete block
to allow the wire to be wrapped around
it. When confronted with this problem,
Olvex specialists had to introduce
some innovations. Jointly with CEDIMA
engineers, they developed and tested a
horizontal wire-sawing system consisting
of two ‘downhole’ columns and two sets of
pulleys coming with circular saw CAZ3200. The set-up is shown schematically
in Fig 4. Once placed into pre-cored 300
mm diameter holes, these pulleys allow
diamond wire to be pulled in a horizontal
direction thus making horizontal cuts at
any pre-determined depth.
The above project serves as an
example of how the perfect combination
of a contractor’s massive field experience
and a manufacturer’s innovating thinking
helps find a solution to any problem no
matter how complex. The company feels
that the technology of horizontal wiresawing mastered at these building sites
in Moscow takes it one step further to its
ultimate goal – customers’ satisfaction.
Since both projects, Moscow-city and
WTC-2, were being carried out at the same
time, the company faced a tall order –
INDUSTRIAL DIAMOND REVIEW
1/07
Fig 2 A floor of the building after being cut with diamond wall saws
how to manage its production assets in the
most efficient way under such pressures.
The working process on both sites had
to be planned in such a fashion that
allowed for maximal efficiency, failurefree operation of all equipment, its timely
maintenance and repair and prompt redistribution of personnel and machinery
between sites. It was the company’s
procurement department that bore the
brunt of the load during those hectic days.
Being in a close touch with field operators
and diamond tool manufacturers, the
procurement department would manage to
find and supply the required consumables
to the sites on a just-in-time basis thus
underpinning the operation efficiency at
maximum level.
Quality Management System ISO
9001:2000 and Occupational Health &
Safety Management System OHSAS
18001 the implementation of which is
currently under way at ZAO Olvex made
a significant contribution to the efficient
coordination of the company’s various
departments, ensuring smooth, two-way
communications with customers and
other contractors and zero-accident work
for the staff. Fig 3 A 2 t reinforced concrete block
being lifted away
Fig 4 Schematic showing the method developed
for horizontal diamond wire sawing
Author
Andrei Bushmarin,
ZAO Olvex, St. Petersburg, Russia.
www.olvex.ru
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