New Delhi: The Delhi Metro has designed its
structure to stand earthquakes upto 7.5 on Richter scale and
has installed a censor to send alarm to train operators in
case of tremor of specific magnitude, its spokesman said on Tuesday.
His comments came in the wake of wide-spread
destruction caused by tsunami and earthquake that hit Japan on
The installation of the censor is among some of the
measures taken by the Delhi Metro to avoid disaster both in
the underground and overground corridors if a quake occurs.
"The Delhi Metro structures have thus been designed in
such a manner that they can withstand earthquake forces likely
to occur in Zone 4 of the seismic zone identified in India.
"Zone 4 is called the `High Damage Risk Zone` and covers
areas of Indo-gangetic basin and Delhi, Jammu and Bihar. This
zone is prone to earthquakes of Richter scale 7 to 7.5. This
implies that the Delhi Metro strcutures can withstand
earthquake tremors of 7.5 Richter magnitude," Metro spokesman
Anuj Dayal said.
Delhi Metro civil structures including the Metro
stations, viaducts and underground tunnels have been well
built with sufficient strength to endure maximum stress and strain in case of a quake, he said.
The design of the structures of the Delhi Metro posed
a number of challenges for the engineers especially in the
`underground` sections as there were no Indian codes available
for designing underground civil structures to withstand
earthquakes, he said.
Dayal said the Metro had to followed the British
Standard codes and European codes and literatures for elevated
and underground structures.
An earthquake sensor has been installed at Patel Chowk
underground Metro Station of Line-2 (Jahangirpuri ? HUDA City
Centre) to measure tremors.
"This sensor sounds an alarm whenever there is any
vibration of specified magnitude set as trigger value inside
the surface which has been designed for alerting the Metro
staff and Operation Control Centre (OCC) of the DMRC," he
This sound alarm is generated automatically whenever
it measures vibrations equivalent to 5 on Richter scale or
more which becomes an advance warning system for all Metro