Source: https://www.indianeconomicobserver.com/news/mumbai-ahmedabad-bullet-train-project-14-km-bridge-over-narmada-making-swift-progress20240823232926/
Publisher: Indian Economic Observer
The bridge spanning over 1.4 km getting constructed over the Narmada River in Gujarat as part of the ambitious Mumbai-Ahmedabad Bullet Train Project is making swift progress, according to National High-Speed Rail Corporation Limited press release.
This advancement marks another step forward in the development of India’s first high-speed rail corridor.
This is the longest river bridge in the Gujarat portion of the project and is being constructed on good foundations. A well foundation is a type of deep foundation situated in rivers used to support heavy structures such as bridges, added NHSRCL.
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.
The Narmada HSR bridge consists of 25 nos of well foundations. Five nos. of wells 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.
Giving information about this Managing Director of NHSRCL, Vivek Kumar Gupta said that 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.
The bridge involves 25 well foundations, with five wells reaching depths exceeding 70 meters. The deepest well foundation, measuring 77.11 meters from the well cap top to the founding level, is a remarkable engineering feat. Notably, four of these well foundations will surpass the height of the Qutub Minar, which stands at 72.5 meters.
Gupta further said that 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.
It is notable that the Narmada River, often referred to as the “Life Line of Madhya Pradesh and Gujarat,” flows through central India, and 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 Sarovar 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 construction of the bridge over the mighty river Narmada was affected adversely during the monsoon season and the flood situation in September 2023. A large quantity of water (approx.18 lakh cusec) was released from Sardar Sarovar dam, resulting in damage to the 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 the Jack-Down method, the tilt and shift issues were addressed well in time.
With meticulous planning and a dedicated on-site team, the bridge work has achieved remarkable progress with the completion of 19 foundations out of 25 wells. The work of erection of the superstructure has also commenced.
There are a total of 24 river bridges in the project, 20 are in Gujarat and 4 in Maharashtra. Out of 20 bridges in Gujarat, 10 have been completed.
