Delhi Metro’s Underground Revolution

Anuj Dayal, Executive Director-Corp Comm, DMRC

Delhi Metro’s Underground Revolution

The Delhi Metro’s underground construction in its third phase of expansion cannot be considered anything short of a revolution. Close to 80 kilometres of underground tunnels have been laid beneath the city in the last five years without causing any disruption to the din and bustle of the daily life above.

The sheer enormity of the task can be gauged from the fact that, the total length of the underground corridors in Delhi Metro’s Phase-3 is more than the total underground sections built by DMRC in both Phases 1 and 2, making it one of the most challenging construction phases for the organization.

Combining the first two phases, Delhi Metro has a total of 31 underground stations, while Phase-3 alone has 35 underground stations. The total length of the underground corridors in the first two phases was 48.06 kilometres and Phase-3 alone has underground corridors of 54 kilometres. The first phase of Delhi Metro’s construction had 13.17 kilometres of underground Metro lines while the second phase had 34.89 kilometres.

The decision to construct more underground corridors was taken to ensure that the construction work caused minimum inconvenience to the people. By constructing so many underground stretches, DMRC has also avoided causing any damage to the existing infrastructure such as flyovers and roads.

For the first time in the history of Delhi Metro’s construction, four different tunneling stretches in Phase-3 have passed below existing underground Metro stretches in the city. These four underground stretches are:
Tables
  • Tunnel between Sarojini Nagar to INA on the Majlis Park – Shiv Vihar corridor below the underground section of the Samaypur Badli – HUDA City Centre line at INA.
  • Tunnel between Indira Gandhi Domestic Airport (T1D) to Vasant Vihar on the Janak Puri West – Botanical Garden corridor below the underground section of the Airport Express Link near the Indira Gandhi International Airport (Domestic terminals).
  • Tunnel between Mandi House to ITO on the Escorts Mujesar – Kashmere Gate Corridor below the underground section of the NOIDA – Dwarka corridor (Blue Line) at Mandi House.
  • Tunnel between Hauz Khas and Panchsheel Park on the Janakpuri West – Botanical Garden corridor below the already operational HUDA City Centre – Samaypur Badli section at Hauz Khas.
Tunneling Process

Most of the tunneling was done using Tunnel Boring Machines. A record 30 TBMs were pressed into service to complete the work. It is indeed rare to come across the use of so many TBMs within one urban centre anywhere in the world. In Phase 2, 14 TBMs had been used but this time the number had to be more than doubled.

There were also stretches where it was not possible to use TBMs. For example, at Kalkaji Mandir, the New Austrian Tunneling Method (NATM) was used to carry out tunneling work for a stretch of 176 metres.

Tunneling Process

The tunnel between Kalkaji Mandir and NSIC Okhla passes below piers 135 and 136 of the operational violet line and the distance between the two piers was 28 mtrs. It would have been impossible to construct twin tunnels within such a short space. Therefore, a decision was taken to construct a single tube twin tunnel through which both the tracks will pass using the NATM technology. In another stretch at Kashmere Gate, NATM was used for a stretch of a 12 metre long tunnel.

Monitoring during tunneling work

DMRC has always laid great stress on ensuring that its construction activities cause minimum inconvenience to the general public. During the tunneling work of Phase-3, detailed instrumentation was done at various locations to monitor the condition of buildings and other structures above.

In areas such as Old Delhi, stretches where the tunnels were passing below already operational Metro tunnels or beneath flyovers and bridges, DMRC’s engineers had to be very careful. Various equipment for monitoring the movement of the TBMs were installed such as settlement markers, inclinometers, bi-reflex targets etc. Exhaustive building condition surveys were also conducted at all major locations for the same.

Mass Spring Systems (MSS)

A decision was also taken to install Mass Spring Systems in the tunnels to mitigate vibrations generated from tunnels during the passing of trains. Mass Spring System (MSS) is the solution which helps mitigate vibrations generated by the passing trains at the source itself.

Mass Spring Systems (MSS)

MSS elastically separates the tracks slabs in the tunnels or on the viaducts from the supporting structure. The material used for isolation is a microcellular Polyurethane Elastomer (e.g.- Sylomer from Getzner- Austria). Use of MSS helps in minimizing the transmission of vibrations (structure-borne noise) to the surrounding establishments in the vicinity of tracks. In addition, MSS also effectively reduces the development of audible secondary airborne noise caused by the vibration of buildings and other infrastructure components.

Social Outreach:

DMRC Tunneling Process
Wherever the Delhi Metro carried out construction work, it engaged with the people through numerous Community Interaction Programmes. In these programmes, DMRC’s detailed construction plans were discussed with the residents of the area and all possibilities of road diversions, temporary or permanent displacements etc were deliberated upon. With such initiatives, DMRC could win the trust of the people and progress smoothly with its construction work.

Conclusion

Underground construction has its challenges irrespective of where it is carried out. However, if the construction takes place in a city with close to 20 million people, the challenges simply multiply. Constructing over 50 kilometres of underground lines in Delhi was a major challenge with innumerable buildings and structures in precarious conditions. However, DMRC’s engineers showed great commitment and presence of mind in ensuring that the work could be completed without any major hindrance.

NBM&CW August 2017

Click Here
To Know More / Contact The Manufacturer
Please provide your details we will contact you as soon as possible
Please let us know your name.
Invalid Input
Please let us know your Designation.
Invalid Input
Please let us know your City.
Please let us know your State.
Please let us know your Country.
Please let us know your Contact Number.
Please let us know your email address.
Please brief your query.

Characteristics & Categorization of Tunnel Fires & Their Mitigation

A fire that develops in a tunnel interacts with the ventilation airflow and generates complicated air flow patterns and turbulence in the vicinity. The heat generated warms up the surrounding air, and in case of a slope inside Read More ...

Mapei: Injection Solutions for Underground Construction

Injection can be defined as the introduction of a material with pressure into the ground or a structure for waterproofing and for consolidating voids, cracks and porosity. Generally, the injection can be categorised as Pre Read More ...

Tunnel Renovation Redefined

During renovation of the Hasselborner Tunnel in Central Hesse, Germany, contractor Baresel used a method they hadn't tried before. Parts of the tunnel lining had to be removed and the areas were subsequently Read More ...

GHH adds Shotcreting Machine to its - Tunneling Equipment Solutions

GHH is offering state-of-the-art and proven IS26 Concrete Spraying (Shotcrete) machine in India. The machine is suitable for shotcreting application in medium and large sized tunnels with cross sections ranging Read More ...

Kishanganga Hydro Power project – A New Power House

Inaugurated by the Prime Minister of India, the Kishanganga Hydro Electric Power project is the first mega hydro power plant to be awarded as EPC to HCC by NHPC. Located at Bandipore in north Kashmir, the Read More ...

Tunneling to Prosperity: Solutions, Equipment and Technologies

India is one of the fastest growing markets for tunnel construction due to various infrastructure development projects underway across the country. Tunnels are required for hydroelectric power projects, for improving road Read More ...

CREG: Tunneling Specialist

China-based China Railway Engineering Equipment Group Co., Ltd (CREG) is a subsidiary of the public- listed China Railway Engineering Corporation (CREC), a Fortune 500 company and a key state-owned company under Read More ...

Intermodality & Last Mile Connectivity - Creating Smart Walkable Spaces

Urban congestion needs to be addressed by encouraging high quality and innovative energy-efficient public transport integrating it with other forms of paratransit, ensuring last mile connectivity; working on Read More ...

Ashram Metro Station - An Engineering Masterpiece

One of the main challenges of constructing a station in the Delhi Metro Network, especially in a busy and densely populated area, is designing it according to the ambience and the limited space allocated. Constructing Read More ...

Transit Oriented Development - Challenges and Proposed Regulatory Framework

Transit Oriented Development (TOD) complements the concept of new urbanism. Compact, mixed-use communities are the answer to suburban problems. Due to the dynamic nature and multiplicity of underlying Read More ...

Simulating oversize and heavy vehicle manoeuvres using AutoTURN® from Transoft Solutions.

Use AutoTURN® to design infrastructure adjustments to safely operate trucks transporting wind turbine components. By Er. Alessio Gori - collaborator at POLITECNICA INGEGNERIA ED ARCHITETTURA SOC. COOP. Read More ...

Urgent Course Correction Imperative for Indian Railways

Railways’ freight and passenger businesses over the 5-year period, i.e., 2014-15 to 2018-19 (budgeted) indicate a flat growth. The number of total passenger journeys would record a CAGR of 0.22%, passenger kilometres Read More ...

Meeting Emerging Urban Transport Challenges

The Ministry of Housing and Urban Affairs has envisaged growth of urban transport along with a low carbon footprint through seamless implementation of a New Metro Rail Policy, announced last year Read More ...

Tunnelling Through the Ages

History has seen the evolution of tunnelling starting with cave formation, for water management, underground transportation, mineral extraction and for warfare purposes. The oldest reference of a tunnel was Read More ...

Afcons uses Robbins EPB TBM to Complete Third Bore for Chennai Metro Project

Contractor Afcons Infrastructure Ltd used a 6.65 m (21.8 ft) diameter Robbins EPB TBM to bore through in Chennai Metro, making it the contractor's third tunnel to be bored by the machine for the project. The three Read More ...

Robbins Slurry TBM ramps up for Mumbai Metro Line 3

The first of two Slurry TBMs, a rebuilt 6.65 m (21.8 ft) diameter machine, passed its factory acceptance on September 4, 2017 in Singapore. The machine, fitted with a Robbins cutterhead and outer Read More ...
NBM&CW

New Building Material & Construction World

New Building Material & Construction World
MGS Architecture

Modern Green Structures & Architecture

Modern Green Structures & Architecture
L&ST

Lifting & Specialized Transport

Lifting & Specialized Transport
II&TW

Indian Infrastructure & Tenders Week

Indian Infrastructure & Tenders Week