TERRATEC TBM begins tunnelling work for Delhi Metro’s Phase-4 project

A refurbished 6.52m diameter TERRATEC Earth Pressure Balance (EPB) Tunnel Boring Machine has been delivered to a Joint Venture between Hindustan Construction Company Ltd. of India and Vensar Constructions Company Limited, for the Line-8 – Magenta Line of the Delhi Metro, in New Delhi, India.

  • Followed by a successful Site Acceptance Test, the JV began work to install the first tunnel ring segment for constructing a 2.03 km underground extension of the Delhi Metro’s 38.235 km Magenta Line (Line-8) from the Vikaspuri Park Shaft to Vikaspuri Ramp near Keshopur. 
  • As part of this tunnelling drive, two tunnels (for up and down movement) with a length of 1400 metres will be bored between Vikaspuri and Krishna Park Extension.
  • The Contractor selected TERRATEC 6.52m EPB Tunnel Boring Machine with a traditional soil configuration, equipped with a Spoke-Type Cutter Head with a 57% opening ratio which has been proven to be very efficient to excavate this type of soil in previous DMRC Phases. 

  • This refurbished machine has previously completed tunnels for Delhi Metro project CC-34 and Lucknow Metro project LKCC-06.
  • TERRATEC has designed the CutterHead to allow the cutting tools to be exchangeable for 17’’ roller disc cutters, making the TBM to be able to bore through the D-walls and cope with the presence of any unexpected obstacle on its way, such as old wells or foundations. 
  • The geology is composed of silty sand, fine sand & sandy silt and clayey silt.
  • The segment lining will be made of RC segments with an outer diameter of 6,350mm, inner diameter of 5,800mm and width of 1,400mm. 
  • The total distance that the TBM will bore is approximately 2,030 metres.
  • The tunnel will be excavated at an average depth of 14-16 metres. 
  • As the drives progress, the machines will install reinforced concrete Universal-style, pre-cast lining rings comprising five segments + key. 
  • This section includes a 365 meter long ramp and approximately 220 meter long station, hence roughly 2100 segments will be installed.
  • In January 2020, DMRC had awarded a contract to the consortium of HCC-VCCL for building the construction of twin tunnels from the Vikaspuri Park Shaft to Vikaspuri Ramp, with one underground station at Krishna Park Extension under contract package DC-06 of Delhi Metro Phase 4. 
  • The work is expected to be completed in 36 months.
  • After successful completion of Delhi Metro Phase III, Terratec has been chosen again for the first underground tunnel package in DMRC Phase-IV which proves that Terratec is the first choice for the contractors. 
  • TERRATEC’s continuing success on projects such as Phase III of the Delhi Metro, Lucknow Metro, Pune Metro, Ahmedabad Metro and Mumbai Metro is a result of tailor-made robust TBM design, prompt onsite assistance, readily available stock of TBM spares and highly-skilled specialised TBM support throughout tunnelling operations.

Source: TERRATEC-Press Release