Metro to bore tunnel under drain
A new tunnel will be build by Delhi Metro for the new Janakpuri (West) to Botanical Garden corridor right under the Chirag Dilli drain. In this segment the tunnel will be going 16m under the surface, around 4.1m under the Chirag Dilli drain. Delhi Metro says this is an engineering challenge where the construction will have to factor in not only the weight of the 10m wide drain but also the regular danger of seepage from it. One of the oldest in this area is the Chirag Dilli drain.
Dayal alleged, This section of the tunnel which is between Chirag Delhi and Panchsheel Park metro station on Outer Ring Road, will go by about 4.1m under the base foundation of the drain. Delhi Metro Rail Corporation (DMRC) spokesman Anuj Dayal said, the breadth of the drain is approximately 10m at this point. As per DMRC it is difficult to construct tunnels below drains or water bodies. Dayal added, during construction there is a continuous possibility of water seeping into the tunnel as well as operation. The longevity of the civil structures will be severely affected by such seepages and that may even lead to collapse of the tunnel.
DMRC has put in place round-the-clock monitoring of the tunnelling work, to protect the tunnel and to ensure smooth and safe construction. Dayal explained, by use of various sophisticated equipment Monitoring will be done to check if there is any settlement around the tunnel or any abnormal leaning of the tunnel or the culvert above the drain which connects with Outer Ring Road. Some of the hi –tech equipments were used like surface settlement targets (for monitoring settlement of the surface above), inclinometers and extensionometers (for monitoring settlement of the area around the tunnel above), tilt meters (to monitor if the civil structure is unnaturally tilting) etc.Dayal added, to ensure that there is adequate space between the water body and the tunnel, the tunnelling will be done 4.1m below the surface foundation of the drain. This will guarantee that there is no prospect of any seepage or flooding of water into the tunnel from the drain.
In September, the tunnelling work from Chirag Delhi to Panchsheel Park is expected to start and probable to complete by early next year. Dayal further added this will be the first case of a tunnel being constructed below a drain in Pase III.Alike underground tunnels below drains were constructed and canals in Pase II in GTB Nagar and Jungpura.
Source: Times of India
Anuj Dayal, Botanical Garden, Chirag Delhi, Chirag Dilli drain, civil structures, Delhi Metro Rail Corporation, DMRC, Drain, Extensionometers, GTB Nagar, Inclinometers, Janakpuri West, Jungpura, Outer Ring Road, Panchsheel Park, Tilt meters
