Chenab Bridge
Encyclopedia
The Chenab Bridge is an arch bridge
under construction in India
. It spans the Chenab River
between Bakkal and Kauri, in Reasi
district of Jammu and Kashmir
. When completed, the bridge will be 1315 m (4,314.3 ft) long, with a 480 m (1,574.8 ft) trussed arch span 359 m (1,177.8 ft) above the river Chenab and a 650 m (2,132.5 ft) long viaduct on the Kauri side.
The bridge is part of several bridges and tunnels which makes up the Katra-Laole Section of the USBRL Project
in Jammu and Kashmir
. Another, smaller, arch bridge in the link will be the 657 m (2,155.5 ft) long, 189 m (620.1 ft) high Anji Khad bridge between Katra
and Reasi
.
The Chenab Bridge was scheduled to be completed in December 2009. In September 2008 it was announced that the Chenab bridge was canceled despite the completion of the approach viaducts in 2007. As of mid-2009, the latest word is that the original route is back on track and the bridge will be built as originally planned with completion circa 2015.
has undertaken the mega-project of construction of a new railway line
in the state of Jammu and Kashmir
, from Udhampur
to Baramulla
, which has been declared a national project. The alignment is a culmination of a large number of tunnels and bridges which are to be implemented in highly rugged and mountainous terrain, with the difficult Himalayan
geology. The alignment crosses a deep gorge of the Chenab River, near Salal Hydro Power Dam, which necessitates construction of a long span bridge. After many deliberations, the configurations of steel arches were found most suitable, on account of aesthetics, economy, and availability of local expertise and construction materials.
The Chenab Bridge, 359 m (1,177.8 ft) above river bed, will be the highest arch bridge in the world, and longest span for a BG
rail line with arch span of 480 m (1,574.8 ft). This bridge is in the most difficult part of the project which has been assigned to the Konkan Railway
Corporation Ltd. Many experts throughout the globe, based on their versatile and relevant experience, have been involved, in order to make this project a success.
National codes of India, Indian Railway Standards (IRS), Indian Road Congress (IRC) and Indian Standards (IS) have been supplemented with International standards; British Standards (BS), International Union of Railways (UIC) and Euro, as national codes, were found inadequate for such large spans. The Quality aspect has been emphasized, as the quantum of fabrication and welding is colossal. Mostly indigenous material has been planned to be used, whereas for the design, international codes have been referred, which means the Quality Control work is still difficult.
Regular painting of such bridges is an intimidating task; hence, a painting scheme has been developed, having life over 15 years, compared to 5 to 7 years (approx.) of life in most of the Indian railway bridges. The erection scheme for the bridge is a project in itself, where two pylons (about 130 m and 100 m high) are to be erected on either side of the river, and two auxiliary cable cranes (Capacity 80T each), consisting of self-propelled equipment, will be running on the carrying ropes across these pylons.
The numbers of bearings have been minimized, particularly on the approach viaduct, through the use of continuous construction. This is advantageous, as it reduces the maintenance and inspection efforts, and improves the riding quality. The viaduct piers are of concrete, while the piers near the arch are in steel.
The design of major arch rail bridges requires considerations of a number of additional parameters, such as fatigue, global stability, second order effects, composite action, etc. It also requires that such a bridge is designed to achieve a consistent level of reliability for all load cases, and that the design standards match the construction standards.
The Indian Railway Standards (IRS) is primarily intended for simply supported bridges with spans up to 100m (although these have been successfully used for higher spans up to 154m). The spans proposed for this bridge greatly exceed this limit, and are continuous. In order to provide these additional features, it will be necessary to augment the design with additional international codes and standards that enable the designer to produce a safe design.
Following are some of the special features of structural design for the bridges:
Anji Khad Bridge, with its 265m-long main arch span, at a height of 189m from the bed level, is perceptible. Many experts throughout the globe, based on their versatile and relevant experience, have been involved in order to make this project a success. National codes (IRS, IRC and IS) have been supplemented with International standards (BS, UIC and Euro), as national codes were found inadequate for such large spans. The Quality aspect has been emphasized, as the quantum of fabrication and welding is colossal.
The material procurement has been done as per IS codes, whereas for the design, international codes have been referred, which means the Quality Control work is still difficult. Regular painting of such bridges is an intimidating task; hence, a special painting scheme has been developed, having life over 15 years, compared to 5 to 7 years of life in most of the Indian railway bridges.
Arch bridge
An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side...
under construction in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
. It spans the Chenab River
Chenab River
The Chenab River چنRiver' آب) is a major river of Jammu and Kashmir and the Punjab in Pakistan. It forms in the upper Himalayas in the Lahaul and Spiti district of Himachal Pradesh, India, and flows through the Jammu region of Jammu and Kashmir into the plains of the Punjab, Pakistan...
between Bakkal and Kauri, in Reasi
Reasi
Reasi is a town and a notified area committee, tehsil and now a district in the Indian state of Jammu and Kashmir. It is situated at the bank of River Chenab. Reasi derived its name from its old name "RASYAL".Rasyal is a caste belongs to Rajput Category. In the eighth century Reasi was called...
district of Jammu and Kashmir
Jammu and Kashmir
Jammu and Kashmir is the northernmost state of India. It is situated mostly in the Himalayan mountains. Jammu and Kashmir shares a border with the states of Himachal Pradesh and Punjab to the south and internationally with the People's Republic of China to the north and east and the...
. When completed, the bridge will be 1315 m (4,314.3 ft) long, with a 480 m (1,574.8 ft) trussed arch span 359 m (1,177.8 ft) above the river Chenab and a 650 m (2,132.5 ft) long viaduct on the Kauri side.
The bridge is part of several bridges and tunnels which makes up the Katra-Laole Section of the USBRL Project
Kashmir Railway
The Kashmir Railway is a railway line being built in India to connect the state of Jammu and Kashmir with the rest of the country. Officially termed the Jammu Udhampur Srinagar Baramulla Railway Link , the railway starts from Jammu and, when completed, will travel for to the city of Baramulla on...
in Jammu and Kashmir
Jammu and Kashmir
Jammu and Kashmir is the northernmost state of India. It is situated mostly in the Himalayan mountains. Jammu and Kashmir shares a border with the states of Himachal Pradesh and Punjab to the south and internationally with the People's Republic of China to the north and east and the...
. Another, smaller, arch bridge in the link will be the 657 m (2,155.5 ft) long, 189 m (620.1 ft) high Anji Khad bridge between Katra
Katra
Katra or Katra Vaishno Devi, as it is popularly known, is a small town in Jammu and Kashmir, India, situated in the foothills of the Trikuta Mountains, where the holy shrine of Mata Vaishno Devi is located...
and Reasi
Reasi
Reasi is a town and a notified area committee, tehsil and now a district in the Indian state of Jammu and Kashmir. It is situated at the bank of River Chenab. Reasi derived its name from its old name "RASYAL".Rasyal is a caste belongs to Rajput Category. In the eighth century Reasi was called...
.
The Chenab Bridge was scheduled to be completed in December 2009. In September 2008 it was announced that the Chenab bridge was canceled despite the completion of the approach viaducts in 2007. As of mid-2009, the latest word is that the original route is back on track and the bridge will be built as originally planned with completion circa 2015.
Introduction and Topography
Indian RailwaysIndian Railways
Indian Railways , abbreviated as IR , is a departmental undertaking of Government of India, which owns and operates most of India's rail transport. It is overseen by the Ministry of Railways of the Government of India....
has undertaken the mega-project of construction of a new railway line
Kashmir Railway
The Kashmir Railway is a railway line being built in India to connect the state of Jammu and Kashmir with the rest of the country. Officially termed the Jammu Udhampur Srinagar Baramulla Railway Link , the railway starts from Jammu and, when completed, will travel for to the city of Baramulla on...
in the state of Jammu and Kashmir
Jammu and Kashmir
Jammu and Kashmir is the northernmost state of India. It is situated mostly in the Himalayan mountains. Jammu and Kashmir shares a border with the states of Himachal Pradesh and Punjab to the south and internationally with the People's Republic of China to the north and east and the...
, from Udhampur
Udhampur
Udhampur is a city and a municipal council in Udhampur District in the Indian state of Jammu and Kashmir. It is the second lardest city of Duggardesh region and the fourth largest city in the state of Jammu and Kashmir. It serves as the district capital and the Northern Command headquarter of the...
to Baramulla
Baramulla
Baramulla , known as Varahamula in antiquity, is a city in the Baramulla district in Jammu and Kashmir state in northern India...
, which has been declared a national project. The alignment is a culmination of a large number of tunnels and bridges which are to be implemented in highly rugged and mountainous terrain, with the difficult Himalayan
Himalayas
The Himalaya Range or Himalaya Mountains Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range in Asia, separating the Indian subcontinent from the Tibetan Plateau...
geology. The alignment crosses a deep gorge of the Chenab River, near Salal Hydro Power Dam, which necessitates construction of a long span bridge. After many deliberations, the configurations of steel arches were found most suitable, on account of aesthetics, economy, and availability of local expertise and construction materials.
The Chenab Bridge, 359 m (1,177.8 ft) above river bed, will be the highest arch bridge in the world, and longest span for a BG
Indian gauge
Indian gauge is a track gauge commonly used in India, Pakistan, Bangladesh, Sri Lanka, Argentina and Chile. It is also the gauge that is used on BART , in northern California.- Scotland :...
rail line with arch span of 480 m (1,574.8 ft). This bridge is in the most difficult part of the project which has been assigned to the Konkan Railway
Konkan Railway
The Konkan Railway is a railway line which runs along the Konkan coast of India. It was constructed and is operated by the Konkan Railway Corporation...
Corporation Ltd. Many experts throughout the globe, based on their versatile and relevant experience, have been involved, in order to make this project a success.
National codes of India, Indian Railway Standards (IRS), Indian Road Congress (IRC) and Indian Standards (IS) have been supplemented with International standards; British Standards (BS), International Union of Railways (UIC) and Euro, as national codes, were found inadequate for such large spans. The Quality aspect has been emphasized, as the quantum of fabrication and welding is colossal. Mostly indigenous material has been planned to be used, whereas for the design, international codes have been referred, which means the Quality Control work is still difficult.
Regular painting of such bridges is an intimidating task; hence, a painting scheme has been developed, having life over 15 years, compared to 5 to 7 years (approx.) of life in most of the Indian railway bridges. The erection scheme for the bridge is a project in itself, where two pylons (about 130 m and 100 m high) are to be erected on either side of the river, and two auxiliary cable cranes (Capacity 80T each), consisting of self-propelled equipment, will be running on the carrying ropes across these pylons.
Special Considerations
The structural concept of the bridge over the river Chenab is a large span arch over the river, with approach viaducts on either side. The proposed arch is a two-ribbed arch, fabricated from large steel trusses. The chords of the trusses will be sealed steel boxes, filled with concrete to assist in controlling wind-induced forces on the bridge. Another advantage of concrete filling is that internal painting will not be required. The boxes will be stiffened internally.The numbers of bearings have been minimized, particularly on the approach viaduct, through the use of continuous construction. This is advantageous, as it reduces the maintenance and inspection efforts, and improves the riding quality. The viaduct piers are of concrete, while the piers near the arch are in steel.
The design of major arch rail bridges requires considerations of a number of additional parameters, such as fatigue, global stability, second order effects, composite action, etc. It also requires that such a bridge is designed to achieve a consistent level of reliability for all load cases, and that the design standards match the construction standards.
The Indian Railway Standards (IRS) is primarily intended for simply supported bridges with spans up to 100m (although these have been successfully used for higher spans up to 154m). The spans proposed for this bridge greatly exceed this limit, and are continuous. In order to provide these additional features, it will be necessary to augment the design with additional international codes and standards that enable the designer to produce a safe design.
Following are some of the special features of structural design for the bridges:
- Limit state philosophy of design has been decided to be followed as per BS codes.
- Computation of wind load effects as per Wind tunnel tests
- Site specific seismic spectra developed by Indian Institute of Technology (IIT) Roorkee.
- Provision of Euro code 8 for ductility detailing of very tall and hollow rectangular RCC piers.
- Provision of long welded rail (LWR) over the bridges and resulting force calculation as per UIC – 774-3R guidelines.
- Blast resistant design has been used.
- Design checking for fatigue as per BS codes.
- Deformation limits as per comfort criteria of UIC – 776-2R and UIC 776 -3R guidelines.
- Redundancy provided in the structures, for lower level of operation during mishaps and against collapse in extreme cases of one pier failure.
Anji Khad Bridge
The alignment is a culmination of large number of tunnels and bridges which are to be implemented in highly rugged and mountainous terrain, with mostly difficult Himalayan geology. The alignment crosses deep gorges of Anji-Khad near Reasi, which necessitates construction of a long span bridge. After many deliberations, the configurations of steel arches were found most suitable on account of aesthetics, economy, and availability of local expertise and construction materials.Anji Khad Bridge, with its 265m-long main arch span, at a height of 189m from the bed level, is perceptible. Many experts throughout the globe, based on their versatile and relevant experience, have been involved in order to make this project a success. National codes (IRS, IRC and IS) have been supplemented with International standards (BS, UIC and Euro), as national codes were found inadequate for such large spans. The Quality aspect has been emphasized, as the quantum of fabrication and welding is colossal.
The material procurement has been done as per IS codes, whereas for the design, international codes have been referred, which means the Quality Control work is still difficult. Regular painting of such bridges is an intimidating task; hence, a special painting scheme has been developed, having life over 15 years, compared to 5 to 7 years of life in most of the Indian railway bridges.