A Small & Beautiful Arch Bridge inaugurated by CM/Meghalaya
The "Wahrew Bridge" at Sohbar, constructed at ₹49.395 crores under NLCPR, connecting Bholaganj and Sohbar to Nongjri by Conrad Sangma, CM/Meghalaya on 22nd January, 2021.
Inaugurated the Longest Road Arch Bridge in India, the “Wahrew Bridge” at Sohbar, constructed at ₹49.395 crores under NLCPR of @MDoNER_India, connecting Bholaganj and Sohbar to Nongjri by Conrad Sangma, Chief Minister, Government of Meghalaya on 22nd January, 2021. He dedicated this bridge to the progress of the area.
Alok Kumar Verma, IRSE (Rtd.)
Recently India’s longest span road arch bridge was inaugurated. With a span 169.4 m, this bridge is in East Khasi Hills of North East state of Meghalaya.
Arch bridge is a good option for long span bridges in hilly terrain, but this type of bridge requires strong and stable foundations.
This is why in the Himalayas the foundations of this type of bridge are invariably located near the valley floor and not up the slopes.
The Coronation Bridge which was built in 1937-41 over Teesta River near Sivok on the road to Gangtok is one of the oldest such bridges. With a reinforced concrete span of 250 feet, it was a feat of engineering in the late 1930s.
The mega arch bridge being built over Chenab has multiple problems:
Most important being the location of the foundations on the steep slopes in crushed dolomite rocks more than 200 m above the river bed.
The other two major problems are:
1. The deck which will carry the railway tracks is supported on the arch and not suspended from the arch as in the above mentioned road bridge in Meghalaya and also the mega Railway arch bridge on Brahmaputra in Tibet.
2. A supported deck exerts higher forces on the foundations.
3. Erection is also difficult because of high wind forces at such a height (359m).
4. Narrow width of the arch at the foundations.
5. This also results in higher forces on the foundations. This should have been about 50% wider.
In the link below, anyone can read my earlier post that the Chenab Bridge is not an example of good engineering.
In fact it is possibly the most bungled Railway project.
Chenab Mega Arch Bridge:
World’s tallest railway bridge in the making or World’s Most Bungled Railway Project?
#Kashmir_rail_link #railways_in_himalayas
Chenab Mega Arch Bridge: World's tallest railway bridge in the making or World's Most Bungled Railway Project?#Kashmir_rail_link #railways_in_himalayas https://t.co/B5BQU5lBwS
— Trains Are Best, Alok Kumar Verma, IRSE (Retd) (@trains_are_best) September 9, 2020