Patna Metro : In Corridor II, the initial drive of Tunnel Boring Machine (TBM) 1 has been successfully completed

Patna: The construction work of the underground metro station and tunnel in Corridor II of the Patna Metro Rail Project is progressing rapidly. As part of this, TBM 1 located at Moin-ul-Haq Underground Metro Station has successfully completed its 85-meter journey. The initial drive of the construction work for the underground metro station was underway here. After completing the 85-meter journey, the main drive was initiated by TBM from Friday. Approximately 20 days are required for the installation of backup gantries in the TBM to start the main drive.

It is noteworthy that the construction of the underground metro line using Tunnel Boring Machine is divided into three phases. The first phase involves the initial drive, where the TBM starts the excavation work from the launching shaft. In this phase, the initial or temporary ring segments are manually installed, which help to advance the TBM with the help of the thrust jacks installed in the machine. After that, the TBM reaches the main drive, where it constructs the tunnel while installing permanent ring segments.

The Tunnel Boring Machine is divided into various parts. The front shield of the TBM has a cutting head, which helps the TBM to excavate the tunnel by cutting through the soil. The cutting head also has a provision for the release of a special kind of chemical, which is sprayed on the soil through nozzles on the cutting head. This chemical prevents the soil from sticking to the cutting head, and it is easily conveyed through the conveyor belt installed in the rear part of the machine to the dumping area outside the tunnel, where it is sent out of the tunnel using trolleys.”