Rail Analysis India May Digital Edition 2018 | Page 40

40 | Article
It is about 40 metres long and 12 metres wide. The AFC
Gates, located at the concourse at the earlier station have
been brought to the ground level in the new interchange
station. There is a two metre level difference on the ramp
between the old and the new station. To prevent disturbance
to the residents, sound barriers were installed at Hauz Khas.
These sound barriers are continuing all along the station box.
These barriers lead to about 32 to 35 percent reduction in
noise. The adjacent residential area is Sarvapriya Vihar.
As sound barriers, puff sheets, which are sound absorbing
material are installed at on the inner side of the barricades.
Similar barriers have also been put up at Vasant Vihar.
Tunnel below
landmark
To counter this challenge and ensure the safety of the
station and the hutments above, a detailed building condition
survey of the elevated station and hutments were carried
out. Subsequently, a monitoring plan was prepared. Building
settlement markers, Inclinometers, Surface settlement
markers were installed to monitor the condition of the
buildings and ground, during boring. The Tunnelling team
was also constantly monitoring the Earth Pressure, quantity
of Grouting and Muck Disposal quantity during tunnelling to
ensure that boring was completed without any adverse effect
to the structures. The Hauz Khas interchange: Delhi Metro’s deepest
station
As a result, there was no requirement to hamper the services
on the busy blue line, which is one of the arterial corridors of
the Delhi Metro network and carries about eight lakh people
every day. The stretch also included a Crossover Tunnel
Section of 100 metres which was to be constructed using
conventional methods. Therefore, in order to transfer the
TBM from one end of the Crossover to the other, 2 no. push
ram cylinders were used to push the TBM shield (approx wt.
400 MT) for the stretch of 100 m. The new station has been connected with the presently
operational station through a ramp. The present Hauz Khas
station starts near the Laxman Public school and proceeds
up to almost the median of the Outer Ring Road. The present
station at Hauz Khas is 17 mtrs deep. For the construction of
the new station, it was not possible to go below the existing
station, as the foundation is 32 metres and there is the
foundation of the flyover on Outer Ring Road also.
www.railanalysis.com
tunnel:
another
engineering
Along with the interchange station, the underground corridor of
the Janakpuri West – Botanical Garden line also crisscrossed
with the already operational Yellow Line of the Delhi Metro
network at Hauz Khas. Therefore, the tunnels of the new line
are also passing below those of the functional line.
Image Credits : DMRC
This was another engineering landmark since the TBM shield
was dragged from one point to the other. Generally, TBMs are
retrieved through custom made retrieval shafts and then re-
inserted through launching shafts in the new location. But such
conventional engineering would have involved construction
of separate retrieval and launching shafts, which would have
required more land and displacement of properties above.
In addition, the process would have required a month each
approximately for the retrieval and then the launching of the
TBM. To avoid these hassles, the TBM shield was dragged
using push ram cylinders.
a
Construction of the Hauz Khas station was a massive
challenge for the Delhi Metro team. Since it was an
interchange facility, the engineers also had to ensure that the
inter connectivity between the old and the new portions of
the Hauz Khas station was seamless and comfortable. Like
all other interchange stations of the Delhi Metro network, this
station also has paid area to paid area connectivity between
the new and the old Hauz Khas stations.
Therefore, if the new station had to be constructed below the
existing station, we would have to go deep up to about 42
metres, which would have been very difficult. So, the new
station has been built adjacent to the existing station at a
depth of 29 metres with a length of 265 metres. It has been
designed as a five level station (rail – platform – intermediate
– intermediate – concourse). Generally interchange stations
have three or in some cases four levels only. A subway is
connecting the new and the old stations. An old subway in
the unpaid area of the station has been converted into a paid
subway connecting the old and the new stations.
In Phase 2, the tunnel of the Airport Express Line had
passed below the two tier Rajiv Chowk Metro station at a
depth of about 45 metres. However, that apart such a feat
had never ever been achieved in Delhi Metro in its first two
phases. In Phase 3, apart from Hauz Khas, tunnels have
been constructed below operational tunnels at three other
locations.
The new Metro tunnel at Hauz Khas is about 29 metres
deep at a point just after the station. We have passed three
metres below the existing tunnel. Proper measures were
taken to prevent any movement of the existing tunnel.
Settlement chances were prevented through grouting. D
Wall was constructed around the existing tunnel to provide
support while the new tunnel was being created. Adequate
instrumentation to monitor the movement of the existing
tunnel was also done.
Escalators with the highest elevation in India have
been installed at Janakpuri West
The escalators installed at the new Janakpuri West Metro
station have the highest elevation for any escalator in India.
These escalators have a height of 15.65 metres which
surpasses the escalators installed at the Kashmere Gate
Metro station which have a height of 14.575 metres. The
horizontal length of the escalators are 35.32 metres. The
height of these escalators are equal to a five storey building.
The weight of each escalator was 26 tonnes and a 250
tonne crane was specially planted for the installation of these
escalators.
Artwork at Metro stations
Like the other Metro stations of the Delhi Metro network,
the stations on this corridor have also been decorated with
artworks and paintings. Different themes have been used at
different stations and a number of artists have been roped in
to execute the work. For example, at Chirag Delhi, an artwork
depicting butterflies has been installed since there is a nursery
in the vicinity of the station where many butter flies hover over
the plants. Interestingly, the artwork at GK Enclave depicts
the many trends in fashion.
A special kind of print has been installed on the ceilings
of some of the stations which are also contributing to their
overall look and feel.
For example, at Pa lam, the ceiling of one of the entry/exit
points has been decorated with special prints which depict
the blue skies. This new innovation has enhanced the beauty
of the stations in a major way.
Operational details:
After the Magenta line fully opens, the corridor will operate
with 24 trains which will gradually increase to 26 apart from
the operating reserves. The frequency will be 5 minutes and
15 seconds during peak hours through the whole section and
if passenger traffic demands shorter intermediate loops with
higher frequency will be introduced after studying the traffic
pattern.
Image Credit : wikipedia
While the services will start from 6 AM on all days, on
Sundays, the services will begin at 8 AM. The total running
time between Botanical Garden and Janakpuri West will be
one hour.
www.railanalysis.com