Start of underground construction works for Delhi-Meerut RRTS project
New Delhi, India (Urban Transport News): Construction of the launch shaft has started today at Anand Vihar, Delhi for the tunneling works. The first diaphragm wall panel reinforcement cage (D-Wall) with a size of about 20 m deep (equal to the height of a 10-storey building) and 5 m wide was lowered and concreted. With this milestone, the construction of the underground section for RRTS has entered the next stage.
The D-wall acts as a shield or frame to balance earth pressure, thereby reducing the possibility of soil collapse and also preventing water ingress during excavation.
This launch pit is 20m long and 16m wide, located south of Anand Vihar RRTS underground station. Two tunnel boring machines (TBM) will be lowered into this shaft to drill twin RRTS tunnels from Anand Vihar towards Sarai Kale Khan.
The total route of these two TBM machines will be approximately 3 km. It will be the longest section of tunnel between two stations among the metro systems available in the country. A ventilation shaft will be built between this large section connecting the two sides of the tunnels, to ensure passenger safety in the event of an emergency. An emergency passenger evacuation facility is also being built to facilitate the safe exit of passengers from the tunnels, in the rare event that an evacuation is required.
Meanwhile, the construction of the North Tunnel launch shaft will start soon to drill twin tunnels over 2 km in length from Anand Vihar to Meerut.
These tunnels will have a larger diameter than the country’s metro systems due to larger rolling stock and a higher design speed of 180 km/h in the case of the RRTS. The free inner diameter of these tunnels is 6.5 m to reduce atmospheric pressure and passenger discomfort due to the generation of shock waves in the tunnels due to the higher speed of these trains.
The NCRTC team is doing its best to make up for lost time due to the impact of the second wave of COVID-19 restrictions on construction activities and supply chains. safety protocols in line with COVID SOPs.