The construction work of underground metro station and tunnel is going on at a fast pace in Corridor-II of Patna Metro Rail Project. Under which the first TBM 1 located at Moin-Ul-Haq underground metro station has successfully completed its 85 metre journey.
More Details:
- Right now, the initial drive for the construction work of the underground metro station is going on here. The main drive started on Friday by first TBM after completing 85 metres of its journey. It takes about 20 days to add backup gantries to TBM to start the main drive.
- It may be noted that the construction of the underground metro line by tunnel boring machine is mainly divided into three stages. The first stage in this process is the initial (primary) drive, in which the TBM starts digging the tunnel from the launching shaft.
- In this stage, the initial/temporary ring segments are manually fitted, so that the thrust jacks fitted in the machine propel the TBM forward with the help of these temporary ring segments. After this the TBM reaches the main drive, in which the TBM constructs the tunnel by installing permanent ring segments along with the excavation.
- Tunnel boring machine is divided into different parts. The most forward part of the TBM, the front shield, has the cutting head, with the help of which the TBM digs the tunnel by cutting the soil.
- There is also a system of spraying a special type of chemical in the cutting head, which is sprayed on the soil through a nozzle mounted on the cutting head.
- Due to this chemical, the soil does not stick to the cutter head and easily moves to the rear of the machine with the help of a conveyor belt, from where the soil is brought out of the tunnel through a trolley and sent to the dumping area.
Source: Patna Metro- Press Release | Images Credit: Patna Metro
