The construction of a 1.4-kilometer-long bridge over the Narmada River, which is part of the ambitious Bullet Train project in Gujarat, has achieved a significant milestone. This bridge, located between the Surat and Bharuch Bullet Train stations, is set to be the longest river bridge in the Gujarat section of the project.
The design of the bridge includes 25 well foundations, crucial for ensuring the structure's stability and durability. Impressively, the depth of four of these well foundations will surpass the inverted height of the Qutub Minar, highlighting the engineering prowess and scale involved in this infrastructure development.
"The Narmada bullet train bridge consists total 25 well foundations. Five wells of them are more than 70 meters deep and the deepest well foundation (well cap top to founding level of well) in Narmada River is 77.11 meters, and the depth of other well foundations in the river is around 60 meters. 4 nos. of well foundations will surpass the inverted height of the Qutub Minar, one of the tallest structures in India (height of the Qutub Minar is 72.5 meter" said an official National High-Speed Rail Corporation Ltd (NHSRCL).
According to an official from the NHSRCL “As of now, 19 out of the 25 well foundations have been successfully completed, marking a significant milestone in the project. The work of erection of the superstructure has also commenced.”
"The bridge is being constructed on well foundations. A well foundation is a type of deep foundation situated in rivers used to support heavy structures such as bridges. It consists of a hollow, cylindrical structure that is sunk into the ground to a desired depth to provide stability and load-bearing capacity. Well foundations are one of the oldest and most effective foundation types for railways, highways, bridges/viaducts over wide rivers. This method is often used in areas with deep and unstable river beds where other foundation types are not feasible" further added official.
The major challenge associated with well foundation structures is the “Tilt” and “Shift” of wells during the long duration sinking process because of natural forces such as tidal waves, high river flow, and soil conditions at the sinking level.
According to sources, construction of bridge over mighty river Narmada was affected adversely during monsoon season and flood situation in September 2023. A large quantity of water (approx.18 lakh cusec) was released from Sardar Sarovar dam, resulting in damage to temporary steel bridge to facilitate construction, submergence & malfunctioning of on-site heavy-duty cranes, making work-fronts inaccessible and disturbance to electrical connectivity.
"Despite these challenges, the site engineers worked tirelessly day and night to restore the operations. Additional teams were mobilized to continuously monitor the sinking of wells. With the use of Jack-Down method, the tilt and shift issues were addressed well in time" said an official.
NHSRCL MD Shares Engineering Feats And Challenges During Construction Of The Narmada Bridge
"Our engineers are working tirelessly to ensure the successful completion of the bridge on the mighty Narmada River. This bridge is the longest river bridge within the Gujarat segment of the project and involves 25 well foundations. Notably, five of these wells reach depths exceeding 70 meters, with the deepest well foundation measuring an impressive 77.11 meters from the well cap top to the founding level. This is a remarkable engineering feat. In fact, four of these well foundations will surpass the height of the Qutub Minar, which stands at 72.5 meters.", said Vivek Kumar Gupta, Managing Director of NHSRCL.
Giving details on the challenges face Vivek Kumar said, "One of the critical challenges faced during the construction is managing the 'Tilt' and 'Shift' of the wells. This is a complex issue, exacerbated by natural forces such as tidal waves, high river flow, and varying soil conditions at the sinking level. Despite these challenges, our dedicated team continues to push forward with precision and determination."
The Mumbai-Ahmedabad Bullet Train corridor will pass over the Narmada River in the state of Gujarat. The Narmada River, often referred to as the "Life Line of Madhya Pradesh and Gujarat," flows through central India, is deeply significant both culturally and geographically. The river is crucial for water resources, supporting agriculture, drinking water, and hydropower. The Narmada River, with its blend of spirituality, history, and economic importance, continues to play a vital role in the lives of millions.
The third highest concrete dam in India- The Sardar Sarover dam is also on this river which is 1210 meters (3970 feet) in length and the maximum height of the dam is 163 meters above the deepest foundation level.
The Details Of River Bridges In Projects
There are total 24 river bridges in the project, 20 are in Gujarat and 4 in Maharashtra. Out of 20 bridges in Gujarat, ten (10) have been completed on rivers, including Par (320 m) Valsad district, Purna (360 m) Navsari district, Mindhola (240 m) Navsari district, Ambika (200 m) Navsari district, Auranga (320 m) Valsad district, Venganiya (200 m) Navsari district, Mohar (160 m) Kheda district, Dhadhar (120 m) Vadodara district, Kolak River (160 m) Valsad district and Vatrak (280 m), Kheda district.
Salient features of the Narmada bridge
Total spans- 24 . (21X60m + 2X36m + 1X35m)
Total number of well foundations -25
Total number of Piers: 25 circular piers
Height of the Piers: From 14 meter to 18 meter
