Mere magic?

Mere magic?
Magic box, Quick-fix solution box, instant solution box, ready-to-fix box, match box, joker box it has come to stay. BBMP has identified several places across Bangalore with heavy traffic to put up precast underpasses as has been done near the Cauvery junction on Sankey road.

When the construction of the underpass was on at Cauvery junction in February, it received both good and bad publicity. Palike had claimed that it would place the concrete rectangular boxes by digging 4.5 mts in just 72 hours. The joke at that time was the Palike made a typo error in its announcement- instead of 720 hours, it mentioned 72 hours as the deadline! Jokes apart, Palike really hurried through the work. It could open the underpass in about 850 hours.
A BWSSB water supply pipe had to be shifted, water seepage checked and a collapsed wall to be restored… all this and more made many doubt whether the Palike was on the right track.
Bangaloreans no doubt, welcomed the concept of constructing an underpass within a short time. When it comes to time factor, definitely the Cauvery junction work scores over the projects like the Malleswaram underpass which is yet to be ready even 20 months after commencing the work! The Palike successfully bid goodbye to contractors' raj.
Palike feels that use of precast concrete boxes is the best solution to traffic bottlenecks in many signal light junctions. Riding on the success of the Cauvery underpass, it is now busy is constructing a surfacepass near the BDA circle. The work is on near Anand Nagar junction too.
The Cauvery underpass may be ready. But Bangaloreans, especially many technical experts, have raised doubts over the safety aspect of it. There are also comments that it is not futuristic as it is very narrow. The design has also come under fire as those going towards Mekhri circle from the BDA intersection side on Bellary road, have to over the underpass and it is cumbersome. In rainy season, the underpass may become water-logged, it is feared. Palike should have planned it better, many argue.
But Palike Commissioner S Subramanya insists that people who do not know the precast technology are passing the comments. It is for the first time that Palike has executed such project in Bangalore. He was not perturbed by the adverse comments. He says, "I don't want to get into any argument with people who have no knowledge about precast technology. Give me time till April 15. I will complete two projects - surfacepass near the BDA and the underpass near Anand Nagar. Later let us see whether we need a debate on the technology being followed".
Deccan Herald, from today, is offering a forum for Bangaloreans and technical experts to offer their views on how traffic congestion near traffic signals should be eased. We want to know from you whether an underpass or a surfacepass would be the ideal solution. How do you want the precast pathways to be designed? Do you have better solution than the one followed by Palike? If so, write to us.


LEADER SPEAKS

I welcome it

Having such tunnels or surfacepasses is a good idea. I welcome such work wherever there is too much traffic flow. But the Cauvery junction underpass looks small. It should have been wider by a feet or two to give more mobility to vehicles. Definitely the junction needed a bigger underpass. I don't know whether the engineers have taken care to ensure that the underpass don't get water logged during the monsoon. Hope there is an escape route for water. If this aspect is not taken care, then immediately attention should be paid.
Some peculiar art work has been done on the walls of the underpass. Does it reflect some religion? I don't know. But, I have serious objections to such work. It should be removed immediately. Also, landscaping should be taken up to beautify the underpass area so that it adds to aesthetics of the area.

EXPERT SAYS

On Wednesday (March 26) I had to attend Water Day programme at Hotel Capitol. I left my place on Sankey Road around 9 am in my car. I could not cross the BDA junction even at 10 am. I was stuck in the traffic for more than an hour. The underpass at the Cauvery junction has not helped in easing the traffic flow in any way.
Being a structural engineer I am of the opinion that the pre-cast technology is the best technology that one can adopt. But BBMP has failed to implement the technology effectively. The underpass at the Cauvery junction is too narrow.
The width provided is only 4.5 mtr, where only one vehicle can pass at a time. If one vehicle gets stuck due to any technical problem it will affect the traffic flow.
The minimum width of the underpass should have been 7.5 mtr. I have the experience of working in construction where pre-cast elements were used. With my experience I can say there was no problem to provide 7.5 mtr width. Similarly the International airport-bound vehicles have been made to take acute angle turn over the underpass. That affects speed of vehicles. If Palike intends to adopt the same technology elsewhere it is a welcome move. But the Palike has to make implementation of the technology more perfect.
No doubt the technology saves time. As the RCC boxes are prepared earlier, casting time and curing time are saved. Elements are made capable to carry the maximum weight. The underpass constructed with pre-cast elements is no inferior to one constructed following conventional method.
The pre-cast technology has been widely used world over. Even in the construction of National Games village in Bangalore Shirkey, a company based in Pune, used pre-cast elements for buildings. The company has a big pre-cast plant in Pune. I hope in the years to come this technology will be used extensively in India.

Surface pass at BDA intersection

Vehicular traffic projection at BDA junction
(in peak hours)

2008 - 10,000 PCUs/ hour
2011 - 14,000 PCUs/ hour
2026 - 19,000 PCUs/ hour
Total Estimated cost
Rs 1.97 crore
Pre-cast elements
Rs 60 lakh
Lowering elements, post tensioning
Rs 29 lakh
Approach ramps
Rs 74 lakh
Asphalting and other items Rs 44 lakh

What is precast technology?

A technology where major part of the construction work is done out side the worksite. RCC boxes made well before the work begins at the worksite are placed to minimise the duration. It has been widely implemented world over. For the first time Bruhat Bangalore Mahangagar Palike chose this method to construct underpass at Cauvery junction.

Conventional method
In the conventional method everything is done at the worksite. Much of the time is spent on preparing ground for RCC, casting and curing. As it requires more time vehicular movement is affected. Palike began construction of the underpass at Malleshwaram in July 2006. The work is not yet completed.

Underpass means?
An underground passage for movement of vehicles/pedestrians. It reduces congestion at intersection. In case of the Cauvery junction, pre-moulded cement rectangular blocks are placed in a row by digging the road.

Surfacepass means?
It is a passage for movement of vehicles/pedestrians above the ground level. Like in underpass, here too precise cement blocks are placed one after the other. No digging of earth is required as it is above the ground level.