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 and railway connectivity, expanding mass rapid transit systems, and improving urban water supply and sewerage.
Big investments in infrastructure across segments will give a push to tunnel construction. The railways’ capex target for 2018-19 is at an all-time high of ₹1.48 trillion; hydropower capacity is expected to increase by 13 GW in the next five to six years; and around 10% of the upcoming length of metro rail projects is planned as underground. Apart from these, the Bharatmala, Chardham Connectivity, AMRUT, and the Smart Cities Mission will offer ample opportunities to tunnel contractors, consultants, equipment and technology providers.
The tunnel construction industry has witnessed positive breakthroughs in the past few years. A total of 1,900 km of tunnel length has been constructed so far, and about 3,000 km is either under construction or planned for the future. Hydro tunnels account for the largest share, followed by railways, irrigation, metro rail, water supply, sewerage, and roads and highways. Important tunnels such as the Chenani-Nashri road tunnel, the Banihal-Quazigund rail tunnel, the Kashang hydro tunnel, Teesta 3 and Kishanganga Hydro Electric Power, have been commissioned, and several tunnels completed for metro projects in Delhi, Kolkata, Chennai, Lucknow etc.
Sector-wise, hydropower dominates the tunneling market, with the largest length of tunnels constructed in the country. One of the vital projects of this sector is the Upper Siang hydropower project in Arunachal Pradesh which involves construction of 30 tunnels in a horseshoe-shape, which is the most prominent tunnel design across hydropower projects in India. Other key tunnel projects in the sector include the Dibang, Sawalkote, and Subhanshri Middle hydropower projects, all of which will be constructed in the horseshoe shape.
Currently, many landmark and challenging highway tunnel projects in hilly areas are under various stages of planning and execution. These include the 14-km Zojila tunnel, the 9-km Rohtang tunnel on the Leh-Manali highway, the 11.55-km tunnel on the Jiribam Tupul-Imphal rail line, the 4.5-km Char Dham tunnel, and the recently announced Sela Pass tunnel. In addition to these, many metro, railways and hydroelectric projects are underway.
There is a demand for high-tech tunneling equipment as geological complexities are the biggest challenge in tunneling, more so in the Himalayan region and the Western Ghats. Soil and rock investigation, analysis of ground behaviour during tunneling, and assessment of the risks are important considerations. While conventional methods dominate the railway and hydro segments, mechanized methods such as TBM and NATM are gaining traction in the metro and road segments. Contractors are also experimenting with new techniques and methodologies such as the P5 system and ground freezing for the more challenging/special projects, and are using new and innovative materials such as geo-synthetics, geo-membrane, steel anchors and self-drilling rock bolts.
Char Dham Tunnel, Uttarakhand
The ₹1,384-crore tunnel project in Uttarakhand has been approved by the Cabinet Committee on Economic Affairs as part of the Char Dham project to connect Kedarnath, Badrinath, Yamunotri and Gangotri. The tunnel will reduce travel distance from Dharasu to Yamunotri by about 20km and travel time by about an hour.
The construction will entail a 4.531-km long, two-lane bi-directional tunnel (along with 328m approach road) with escape passage including approaches on Dharasu -Yamunotri section between Chainage 25.400 km and Chainage 51.000 km in Uttarakhand.
The project will be falling along NH-134 (old NH-94) and will be built under the EPC model. It is funded under NH (O) Scheme of Ministry of RT&H and forms part of the ambitious Chardham Plan. Its construction period will be 4 years.
The civil construction cost is estimated at ₹1,119.69 crore, while the total project cost is ₹1,383.78 crore including cost of Land Acquisition & Rehabilitation, other pre-construction activities, and Maintenance and Operation cost of tunnel for 4 years.
The tunnel will provide all-weather connectivity to Yamunotri, one of the dham’s on the Chardham Yatra, encouraging regional socio-economic development, trade and tourism. The project will be implemented by the Ministry of Road Transport & Highways (MoRTH) through National Highways & Infrastructure Development Corporation Ltd. (NHIDCL), a wholly state-owned company formed in 2014 for development of highways in states on international borders.
Rohtang Tunnel, Himachal Pradesh
The Rohtang tunnel, which is being constructed at 3,000 metres above sea level, will provide all-season connectivity to Lahaul Valley in Himachal Pradesh. It will be one of the country’s longest road tunnels at approximately 8.8 km. Being built in the Eastern Pir Panjal ranges on the Leh-Manali Highway – under the Rohtang Pass, the horseshoe-shaped tunnel is likely to be completed by 2020.
The development work is being carried out by Border Roads Organisation (BRO) in collaboration with Afcons, a joint venture with Strabag AG. The tunnel will reduce road distance by nearly 46 km and will save up to 5 hours of travel between Manali and Keylong. It has the capacity to ply 3,000 vehicles per day under any weather condition. Located in the Pir Panjal ranges, it will provide ample room for two-way traffic and is designed to cater to a maximum vehicular speed of 80 km per hour. Moreover, it will be a boon for over 20,000 people in the cold regions of Lahaul Valley, who remain cut off from rest of the country in the winter season due to closure of the Rohtang Pass.
This is also a key project for the Defence Ministry as it wants to make the entire Manali-Keylong-Leh highway, which is 475 km long and is used by the armed forces, to reach areas in Ladakh bordering Pakistan and China, and be motorable round the year.
The foundation stone of the ₹1,495 crore project was laid on June 28, 2010, in Solang Valley, but it has missed several deadlines due to harsh climatic conditions and tough geographical conditions in the Himalayas. It has been reported that the delay in construction has led to a cost overrun of over ₹400 crore.
Sela Pass Tunnel, Arunachal Pradesh
The government plans to build a tunnel through the Sela Pass located at an elevation of 13,700 ft to ensure faster movement of troops in Tawang, a strategically-located town in Arunachal Pradesh, bordering China.
The Sela pass, located between the Tawang and West Kameng districts of Arunachal Pradesh, is considered crucial from a strategic perspective. The new tunnel at the Sela pass will cut down travel time to Tawang by over an hour, and will ensure that the stretch from Bomdila to Tawang remains open throughout the year in all weather conditions.
The Border Roads Organisation (BRO) had announced the tunnel project last year, wherein two tunnels of 475m and 1,790m will be constructed. The project is expected to promote tourism and ease military movements in a key region of Arunachal Pradesh. The project also constitutes widening of the single-lane national highway 13 to double lane from the Baisaki army post.
Zojila Pass Tunnel, J&K
The Cabinet Committee on Economic Affairs recently gave its go-ahead to the 14.2-km long Zojila Pass tunnel project in Jammu and Kashmir, with a Parallel Escape (egress) tunnel, excluding approaches between Baltal and Minamarg. The project will be implemented by MoRTH through NHIDCL. IL&FS Transportation has emerged as the lowest bidder for this project.
Situated at an altitude of 11,578 feet on the Srinagar-Kargil-Leh National Highway, it will provide all-weather connectivity to the region which is cut-off from the rest of the country during winters (December to April) due to heavy snowfall and avalanches. The project will also bring about all-round economic and socio-cultural integration of these regions, and boost local employment as local businesses get linked to national markets and tourist traffic increases.
Considered Asia’s longest bi-directional tunnel, it will be an engineering marvel as it will be the first-of-its-kind in such a geographical area, with as many as nine curves, will enable speed of 80 kmph, and will have the latest safety features such as a fully transverse ventilation system, emergency lighting, CCTVs, radio system, pedestrian cross-passages at every 250 metres, emergency telephones, fire-fighting cabinets at every 125 metres, and motorable cross-passages and lay-bys at every 750 metres.
The project will adopt state-of-the-art methods of construction, out-of-the-box technical solutions, and real-time supervisory control and data acquisition. The carbon dioxide would be removed from the tunnel through a tower, seven times higher than the Qutub Minar. Construction time of the project is estimated to be seven years because of the difficult terrain where temperatures can dip to -45 degree Celsius, lack of oxygen, and 25-30 feet of snow.
The civil construction cost of the project is ₹4,899.42 crore, while the total capital cost is ₹6,808.69 crore, and includes cost of land acquisition, resettlement/rehabilitation and other pre-construction activities, and cost of maintenance and operation for four years.
Once complete, the Zojila Pass tunnel will reduce travel time between Srinagar and Leh to 15 minutes from the current 3.5 hours.
Z-Morh Tunnel, J&K
The 6.5 km long Z-Morh road tunnel is being constructed near Gagangair in Ganderbal district of Jammu and Kashmir. Along with the Zojila tunnel (which is 22 km from Z-Morh tunnel towards Leh) the Z-Morh tunnel will ensure year-long road connectivity between Srinagar and Kargil. Besides social and economic development of the region, the tunnel will boost tourism in the Sonmarg region. Once all the tunnels are ready for public use, the journey from Jammu to Leh will reduce from the current 50 hours to about 30 hours, and the entire stretch will be motorable throughout the year.
Z-Morh tunnel, that gets its name from its Z formation between Sonamarg and Gagangir, will be two lane bi-directional, starting at 69.5 km and ending at 81.3 km on NH 1. The 6.5 km long tunnel will be 10m wide and the parallel egress for use in an emergency will be 3.5m wide.
Located at elevation of 2,637 meters (8,652 ft) above sea level, the tunnel is designed for flow of 1,000 vehicles an hour at an approved maximum speed of 80 km per hour. The ₹2,700 crore project is being executed under PPP (DFBOT - Design, Build, Finance, Operate and Transfer Model) by Srinagar-Sonamarg Tunnelway Limited, an IL&FS-owned company, which is also concessionaire for the project. The tunneling is proposed through NATM in view of the fragile Himalayan geology with 2022 the completion timeline estimate.
It will be implemented by NHIDCL, while ITNL has been appointed as EPC contractor, which, in turn, has appointed Apco - Titan (joint venture) as civil construction contractor.
Apco Infratech Pvt Limited is a Lucknow-based infrastructure company of India, and Titan Limited is a company from Turkey engaged in tunnel construction, technical consultancy and manufacturing of various tunneling equipment such as underground drills, shotcrete machines etc. Eptisa of Spain has been appointed the authority engineer to supervise implementation of the project.