Underpass design faulted

Underpass design faulted

A study pointS to major flaws in conception and construction of THE structures

Senthalir S. Bangalore



A pedestrian underpass near Basaveshwara Circle recently showed cracks and was flooded due to rain. Don't be surprised if more and more underpasses in the city show similar leakages and get inundated with rain water once the monsoon sets in.
The ambitious magic-boxes, several of which have been placed across the city by the Bruhat Bangalore Mahanagara Palike (BBMP) as an answer to the city's traffic woes, appear more like Pandora's boxes.
A study conducted by a French student, has found that the magic boxes are badly designed, "unsustainable" and "unsafe".
Regis Catinaud, the French student, is pursuing post-graduation in political science in University of Grenoble, France.
Catinaud, who has studied five magic-box underpasses in the city for his project called 'Urban Science Technology in Society,' told DNA: "The magic boxes have no room for draining out water. Not enough attention has been given to this while fixing the joints of the precast elements. The work on fixing the tops and joints are shoddy."
He pointed out that according to Oral Buyukozturk, the journal of structural engineering published by MIT Press, joints between the segments in precast concrete segmental bridges require special attention in design and construction. Besides others, he studied Anand Nagar and Cauvery Junction magic-box underpasses.
He said entrances to the magic-boxes have a faulty design. "In Anand Nagar underpass, there is a high risk of congestion at the traffic stream intersections provided for U-turns. The underpasses themselves are too narrow. They should have been two or three-lane underpasses. But they have been reduced into single lanes," Regis said. He added that though the magic-box was a new innovation, it had not been implemented properly and were not installed at places where it was required most.
He said an underpass should provide a smooth U-turn but the magic-boxes fail to provide the same. There is no pathway for people outside the underpass, which puts people to a lot of inconvenience, he added.
Suggesting measures for a smoother inflow of traffic, the study underlines that space should be provided for vehicles to take a proper U-turn. "If the space is too narrow, there is a high risk of congestion near underpasses. An engineer should be present at the time of fixing the joints," it said.
However, a BBMP official, who didn't want to be named, said adequate measures have been taken while laying magic-boxes. Engineers were present at the site. If there are any complaints we will address them, he added.