Work of country’s first 4-layer bridge at Gaddigodam hit badly by pandemic
   Date :29-Apr-2021

 4 layer bridge _1 &
 A view of the pillars in place for construction of double decker bridge as part of four layered transport system at Gaddigodam stretch on Kamptee Road (Pic by Satish Raut)
 
 
By Sagar Mohod :
 
Resurgence of COVID-19 pandemic and extra cautious Railway officials have jointly necessitated pushing forward launching of girders for construction of country’s first multi-layer transport system at Gaddigodam bridge. The project uniqueness has set it apart on mega Nagpur Metro project, as the four-layer transport system would be quite unique by itself. Sources said though Maha Metro had earlier received all clearance for the project, a latest communication from Central Railways have again raised some queries about the launching process given the complexity of the project, necessitating deferring the exercise of pushing the pre-cast slabs across the bridge. The construction of double-decker bridge over Gaddigodam is quite challenging owing to narrow space available for placement of heavy cranes to lift and held the heavy concrete slabs.
 
The opening of RuB itself is very small and hence movement of heavy trailers cannot move across which is another big problem. As per the plan, the concrete slabs of fly-over would be pushed from Gaddigodam side towards Gurudwara side on Kamptee Road. Earlier, after receiving go ahead from Central Railway, Metro directed the agency, M/s Afcons, to carry on with their execution plan and thus piling work started quite fast and pillars were raised on either ends of the Gaddigodam railway bridge well in time. First problem arose as the work on station at Gaddigodam got delayed and Metro then rewarded it to Afcons and thus work on putting slab of fly-over from Gol Market to Gaddigodam bridge has got delayed, while on other side the same is completed till Gurudwara. Now, just when the work of erecting steel structures on ground to handle the weight of heavy viaduct portion, a pause button was hit as senior officials in Bridge section at Headquarters want to again examine the process of executing the critical project. The RoB structure consists of pile foundations, piers and portal beams and super structure is steel composite truss girder of 80 m span (open web type).
 
The height of the RoB structure is about 25m from road level. But before starting placement of RoB slabs with total weight of 1650 tonnes, nearly 700 to 800 tonnes of steel centering has to be put in place on the road surface. The task is quite complicated as while putting the centering, the braces too are to be fitted to ensure that the heavy weight of concrete is effectively balanced and it is time consuming work. Given the heavy weight it was proposed to pull up the pre-fabricated slab in three sets--20 mtr span first and then two 30 metres span all to be lifted separately and then integrated above the rail portion. A period of two months is affixed for completing the task and now worry before contractor is that the work on erection of centering work is completed well before monsoon sets in so that the slabs can be launched across the bridge in time. The Gaddigodam four-layer transport involves existing road under bridge (RuB) and existing railway bridge on top of it. The third layer would be the fly-over to facilitate hassle free movement on Kamptee Road from LIC Square till Automotive, a distance of roughly 5.5 km, and on top would be the viaduct for the metro rail.
 
The Kamptee Road stretch is part of Reach-II of Nagpur Metro stretching from Sitabuldi Inter-change to Automotive Square, a distance of 7.30 kms with seven stations in between. After fly-over portion completion, the viaduct construction would begin and M/s Afcons has set a deadline of December 2021 for handing over the 7.30 km stretch to Maha Metro. The importance of Sitabuldi-Automotive stretch is of immense importance for Nagpur Metro as they hope it would help in breaking them even. This is so as projections say Metro might receive high patronage from commuters on this route since maximum work force would prefer to travel in metro to reach work places that are located in this western and Eastern part of city. Apart from Metro, the Railways has also lined up one important work at the Gaddigodam junction, replacement of its bridge on Itarsi line as the current one has been substantial damaged. Unless Railways completes the task of constructing new bridge, Metro work cannot begin. 
 
‘Labour problem due to COVID-19 may delay laying of PCS’ “A 80 tonnes of pre-cast slab (PCS) is to be laid at Gaddigodam for replacing the current damaged girders of the railway bridge. Central Railway’s Nagpur Division that is overseeing the work, has stated that the work would get completed by May 15. But in given current situation due to spike in COVID-19 positive cases and migration of labourers, the work could get delayed,” said Divisional Commercial Manager (DCM) Vipul Suskar.
 
As per information, all the required material like iron cages for centering and PFC have arrived at the site but labour shortage has held up the construction work. Since last six months the Gaddigodam RuB is closed for traffic after a trailer hit the overhead railway bridge that required immediately placement of steel centering as a support till new bridge is constructed. Due to it the road stretch at Gaddigodam RuB was suspended but till today Railways have failed to expedite the work. The single slab would be great relief for RuB users as it would take care of falling night soil from over head passing trains. The current bridge constructed at time of Britishers consists of two separate girders with rail lines on top. But the gap between the rail was quite a headache for road users as whenever a passenger train crossed over the flush from toilets would pour down below.