Kolkata: The tragic incident of the Majerhat bridge collapse recalls the two horrific days of flyover tragedy that was witnessed by the Kolkatans few years ago- the EM bypass bound Ultadanga flyover from VIP Road (2013) and Vivekandana Flyover of Posta (2016). Both the incidents brought back the frightening memories of bridge collapse. But no lesson has been taken from the past flyover tragedies. The Majerhat bridge tragedy proves that. This incident has raised question at Kolkata’s crumbling infrastructure.
The Majerhat bridge connecting Alipore in the north of the city to New Alipore in the south crashed on Tuesday evening, killing one and leaving at least 21 injured. But what caused the collapse of all these three bridges of the city in five years? Where’s the loophole? How much safe are the rest of the flyovers in the city? Geologist Sujib Kar has analyzed it after the Mjaerhat incident of Tuesday.
In a discussion with Kolkata24x7 Kar said, “It has noticed that after the Majerhat incident, everyone pointing fingers at each other. Blame game has began over Kolkata mishap. Actually, everyone is responsible for this situation, there is also fault of the railway department, and PWD is also equally responsible. Yesterday, after getting the information I personally visited the incident site. The important thing that is to be noted that the top layer of the ground structure of Kolkata is formed with alluvial soil. Below this alluvial soil there is another layer that is porous in state, this layer is constructed with sand and pebbles. Due to high porosity it has water retention property.The water from this soil flows in two surface one is towards river Ganga and Bay Of Bengal. This has gradually increased problem in Kolkata. Few more bridges in the city are also in this list. Especially those, which are at the shore of the river Ganga are becoming more prone to havoc. And the impact on the other which are bit far away from the shore will be little later. But the impact is must.”
“The Metro Rail construction is a giant project, vibration is caused during it’s construction. On the other side the Sealdah south section railway track is located beside this. A low vibration occurs in the ground whenever any train passes through that area. The second thing is that there is a canal on the other side of this place that also pulls a lot of water through the surface flow. As a result, the ground structure of this place has become completely porous. Apart from this many heavy vehicles especially, goods laden trucks have passed through this bridge. More importantly insufficient maintenance work. If you go down and look at the middle of the bridge, you can still see the Taratala Bridge standing with a support. The structure of the soil in this area is in such a condition that proper soil examination is must before any construction. Regular monitoring of soil structure is also need in this case. But there is no proper equipments for monitoring the soil in our state.”
“The most crucial condition among the other bridges in Kolkata is the Maa Flyover at Park Circus Seven Point crossing. The vibration in this seven point crossing is having huge impact on its soil. Hence, this is also another bridge prone to havoc. Every year before arrival of winter this area is effected by soil erosion.Long time ago, warning was given about the Majerhat bridge. Beside this, Dhakuria, Chetla, Brasebridge are also included in the list of bridges that are prone to havoc. A team of scientists and technologists who understands these things should be given responsibility for regularly monitoring of these bridges.Regular survey is needed. Necessary instruments has to be brought. Two or three bor-wells should be made and their data should be checked regularly,” Kar concludes.
Reported By: Debjani Sarkar
Edited By: Mousumi Das