The Delhi Metro Rail Corporation (DMRC) is developing over 40 kilometers of new underground corridors as part of its fourth phase expansion, and according to a senior DMRC official, this will cover about 50 kilometers of the total line being developed across five different corridors. It is said that it accounts for 1%.
A total of 27 metro stations are being constructed in the fourth phase.
DMRC has already completed a small underground section of about 2 km from Janakpuri West to Krishna Park. This is an extension of the magenta line, the officer said.
Delhi Metro is constructing 40.109 kilometers of new underground corridors as part of the fourth phase expansion, under which around 86 kilometers of new lines will be laid in five different corridors.
This is a major technical challenge as the underground passage passes through various geological formations, including dense residential and commercial areas such as Sadar Bazaar, Navi Karim, Mehrauli Badarpur Road, Ajmal Khan Park and New Delhi. He said that there is.
Generally, DMRC constructs metro stations using conventional trenchless technology and tunnels are constructed with the help of tunnel boring machines (TBM), the official said.
A TBM is a machine used to excavate circular cross-section tunnels in various soils and rock formations. He said it can be designed to penetrate everything from hard rock to sand.
A small section of the corridor between Aerocity and Tughlakabad near Tughlakabad will also be constructed using NATM technology (New Austrian Tunneling Method). This tunneling method was also used by DMRC earlier with great success, the official said.
TBMs are particularly useful for underground tunneling in congested urban areas. DMRC has been using TBM for tunnel excavation work since the first stage. In the third phase, where about 50 kilometers of underground sections were constructed, about 30 TBMs were put into service in the capital, he said.
Currently, seven different tunnel excavations have been completed across the Phase 4 corridor and nine excavations are underway at different locations.
“The Aerocity-Tugarkabad corridor has about 19 km of underground passage, while the Janakpuri West-RK Ashram Marg corridor has about 9 km of underground section.The Inderlok-Indraprastha corridor has about 9 km of underground passage. “The corridor has over 11 km of underground lines. There are no metro stations in Majlis Park-Maujpur and Lajpat Nagar-Saket G block sections,” a police officer said.
DMRC is closely monitoring the tunneling work and necessary instrumentation has been put in place to ensure that the condition of the building above is monitored regularly, he added.
