They are saying one can’t erect an important constructing on a weak basis. And undoubtedly not, when it’s the world’s highest railway bridge — now a distinction given to the Chenab Railway Bridge — inaugurated by Prime Minister Narendra Modi on Friday.
The Chenab bridge stays one of many highest factors within the profession of Madhavi Latha G, a professor of civil engineering at Indian Institute of Science (IISc), Bengaluru. Latha labored on the venture for 17 years — from 2005, shortly after becoming a member of IISc, to 2022, when she took her household to the positioning to take a look on the almost-completed bridge.
“Engaged on this venture has been an expertise of a lifetime,” Latha, 54, instructed The Indian Specific. A civil engineering graduate from Jawaharlal Nehru Technological College in Kakinada, Latha went on to pursue her MTech from NIT Warangal and a PhD from IIT Madras, earlier than touchdown a job as assistant professor at IIT Guwahati in 2003. After a yr, she moved to IISc, the place she acquired assigned to this venture.
The Chenab Railway Bridge is a steel-and-concrete construction extending 1,315 m throughout the river gorge. It consists of a 530-metre-long method bridge and a 785-metre-long deck arch bridge (the half on which autos ply). The metal construction can endure excessive climate situations, together with temperatures as little as -20 levels Celsius. It might additionally face up to wind pace of 220 km/hr, which is equal to winds related to an excellent cyclone.
A Vande Bharat prepare crosses the newly inaugurated Chenab rail bridge in J&Okay’s Reasi district, Friday. That is the primary rail hyperlink between the Valley and Jammu area. (PTI)
The area falls beneath seismic zone IV and the proposed bridge needed to have the flexibility to resist earthquakes of magnitude as much as 8 on the Richter scale. Younger mountains with rocky and steep slopes, fractures and joints meant that the civil engineers needed to first put together the bottom in order that the robust basis may very well be laid.
“The area is geotechnically and geologically difficult and near the boundary the place the Himalayas began forming,” Latha stated.
Because the joints have been discovered dipping in the direction of the valley, the opportunity of potential rock slides and slope slides have been excessive, so her design was to repair these from sliding.
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“Any slope is standing towards gravity and it’ll at all times be susceptible to slip off. That is the foremost instability in such terrains. Mountain formation is an end result of tectonic actions and since these mountains are nonetheless younger and repeatedly evolving, there are inherent discontinuities, joints, separations,” she stated, describing the positioning the place the bridge now stands.
Stitching collectively free rock fragments, fixing slopes into the deep Chenab valley and stabilising the bottom in a extremely lively seismic zone to put the bridge’s basis was the duty at her hand. She was primarily answerable for designing safety for the bridge’s basis.
The best railway arch bridge on the planet, soars 359 metres above the Chenab riverbed, its central arch spanning 467 metres.
“Whereas designing, we needed to think about the numerous joints current throughout the slopes which posed a menace of constructing the bottom unstable, particularly if there was seismic exercise. With a purpose to make the bridge quake-resistant, we needed to first stabilise these slopes the place I used to be intensely concerned,” Madhavi Latha stated.
“To stabilise the slope we used cement grouts, in order that free rock fragments, if any, may very well be bonded collectively. As well as, we used metal rock anchors to sew all these joints and join these fragments,” she defined.
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Madhavi Latha stated at one level her skilled abilities have been required almost 24×7, giving her no time to relaxation or sleep.
“At a specific slope reducing, I bear in mind spending sleepless nights as my inputs have been required at each stage. Ferrying folks and equipment to such altitudes makes the on a regular basis work very costly,” she stated.
Her final go to to the positioning with household in 2022 was a giant revelation. “Photos can’t do justice, the magnitude of the bridge hits when one sees it in actual,” she stated.