Delhi-Ghaziabad-Meerut RRTS Corridor achieves complete Tunnelling milestone

New Delhi, India (Metro Rail Today): In a remarkable stride towards enhancing regional connectivity in the National Capital Region (NCR), the National Capital Region Transport Corporation (NCRTC) has achieved a significant milestone - the successful completion of tunnelling for the entire Delhi-Ghaziabad-Meerut RRTS corridor. This achievement was marked by the TBM Breakthrough of Sudarshan 4.4 at the Vaishali retrieving shaft in Ghaziabad. The completion of a 2 km long tunnel between Anand Vihar and Sahibabad signifies the culmination of the tunnel construction for this corridor.

NCRTC's Managing Director, Vinay Kumar Singh, initiated this breakthrough by remotely activating a button. This momentous event was attended by NCRTC's Directors and senior officials. Sudarshan 4.4, initially lowered at the launching shaft at Anand Vihar, has now been successfully retrieved from the Vaishali shaft.

Remarkably, the entire tunnelling process was completed in under 18 months. This achievement was made possible through the utilization of seven advanced Sudarshan Tunnel Boring Machines (TBMs). These TBMs have effectively created parallel tunnels spanning 12 km in the underground segment of the country's pioneering RRTS corridor. Notably, the remaining 70 km of the corridor is elevated, with about 80% of the viaduct already completed.

Over 80,000 high-precision pre-cast segments were employed in the tunnel construction. These segments, each measuring 1.5 meters, were manufactured at state-of-the-art casting yards situated in Kadkaddooma, New Delhi, and Shatabdi Nagar, Meerut. These meticulously designed tunnel segments, when assembled, form tunnel rings. The RRTS tunnels boast an optimized diameter of 6.5 meters, aligned with global tunneling benchmarks for a design speed of 180 km/h, accommodating wider and taller rolling stock.

Delhi Section Tunnelling

The tunnelling journey commenced in February 2022 when the "Sudarshan 4.1" TBM was launched at Anand Vihar, New Delhi. This TBM created a tunnel stretching from Anand Vihar to New Ashok Nagar. Sudarshan 4.2 followed suit for the construction of its parallel tunnel. These parallel tunnels, each around 3 kilometers long, stand as the lengthiest tunnels in Delhi built by a Tunnel Boring Machine. Sudarshan 4.1 accomplished a breakthrough at the Khichdipur retrieval shaft in April 2023, and Sudarshan 4.2 achieved its breakthrough in June 2023.

Moreover, Sudarshan 4.3 and Sudarshan 4.4 were launched from Anand Vihar in June and October 2022, respectively, for the construction of 2-km long parallel tunnels towards Sahibabad RAPIDX Station in the Delhi-Ghaziabad Section. Sudarshan 4.3 achieved its breakthrough in May 2023 near Vaishali Metro Station, and the final TBM, Sudarshan 4.4, accomplished its breakthrough recently.

The Delhi Section presented complex challenges as the tunnels navigated through industrial areas, shallow overburden zones, and beneath high-tension electric cables. Similar complexities were encountered in the New Ashok Nagar direction, involving existing metro viaducts, expressways, and non-engineered buildings. These challenges were effectively addressed through strategic planning and innovative techniques.

Delhi Section Tunnelling

In Meerut, which encompasses underground stations like Meerut Central, Bhainsali, and Begumpul, a total of six parallel tunnels have been constructed. The tunnelling commenced with Sudarshan 8.1 in April 2022 and concluded in July 2023. The intricate urban landscape, including dense populations and existing structures, was successfully navigated during this process.

With the underground tunneling phase completed, focus will now shift to track laying and the installation of overhead electrification systems (OHE). This progress has already commenced at Anand Vihar underground station and Begumpul in Meerut.

Apart from achieving the tunneling milestone, construction of the viaduct between Duhai and Meerut South stations of the Delhi-Ghaziabad-Meerut RRTS corridor has been completed. Of the entire 70-km long elevated section of the first RRTS corridor, a total of 54 km viaduct is now complete.

NCRTC's objective is to make the entire 82-km long Delhi-Ghaziabad-Meerut corridor operational for the public by 2025. Prior to this, a 17-km Priority Section between Sahibabad and Duhai Depot is slated to be operationalized shortly.