The Delhi Metro has designed its structure to stand earthquakes up to 7.5 on Richter scale and has installed a censor to send alarm to train operators in case of tremor of specific magnitude.

A spokesman said that in the wake of wide-spread destruction caused by tsunami and earthquake that hit Japan. The installation of the censor is among some of the measures taken by the Delhi Metro to avoid disaster both in the underground and over ground corridors if a quake occurs.

Metro spokesman Mr Anuj Dayal said that "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.”

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 that 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.

Mr 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. He said that "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 of the DMRC.

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 structures can withstand earthquake tremors of 7.5 Richter magnitude.

(Sourced from ET)