Project Name: Construction of steel super- structure and other ancillary works of rail cum Road Bridge across River Ganga in Patna
Project Owner/ Issuing Authority: East Central Railway
Project Location: Patna, Bihar
IRCON International Limited, a government of India undertaking, was presented with the Achievement Award in the category of Best Construction Projects at the 8 th Edition of the CIDC Vishwakarwa Award held on March 7, 2016, for its Rail- cum- Road- Bridge across River Ganga, Patna.
Least Time and Cost Overrun
Launching of steel truss superstructure starts from September end in 2010. Launch of all the 38 spans was completed in about four and half years’ time. Trial Engine was inaugurated on August 8, 2015.
To achieve this, launching was started from both ends of the river and even a third front for launching was opened on the river using a big barge which reduced the cycle time of launching of girders. Further, five spans were erected on trestles using ground cranes on the islands which surfaced during lean season of the river to reduce construction time.
Engagement of new/ innovative techniques:
- The launch of the spans was done by using the cantilever method in which members are fed from one end of the truss and lifted one by one using cantilever crane mounted on the top of truss over a service track and taken to the extreme end where launching is going on. With this arrangement, only one or two members at a time can taken and the process becomes slow and tedious when it has to travel a number of spans. To overcome this problem, a big barge was used instead, which carried all the members of a panel at a time and members were lifted by the cantilever crane right from the barge. The launching became very fast. Cycle time of erection for one span got reduced to almost half using this technique.
- For efficient handling of the desk slab shuttering, a gantry was developed having a platform at the top and having telescopic jacks at each corners. A system of telescopic beams, cross beams, screw jacks was devised to support large shutters of 7.5m x 11m. The telescopic beams rested on the cross girders of the truss. With this arrangement shuttering and deshuttering was done efficiently.
- Precut and bent reinforcement bars were used to expedite the progress of work.
- E450 grade of steel was used to cater fro launching stresses due to cantilever launching and to reduce the overall weight of the truss.
- The top and bottom chord members of the truss have box sections and inside welding was done using small size SAW welding machines.
- Metalizing of members/ components prone to corrosion has been undertaken to ensure.
- longevity of the bridge.
- Instead of using channels for shear studs of German make (Koco) were used.
Skilled Construction Workers
Deployment of Green Technologies
- Rain water has been collected and used for curing of concrete.
- Steel scrap- Disposed off to vendors for rerolling.
- Used battery- Stored and disposed off to Govt. approved vendors.
- Burnt mobile and spilled oil- stored and disposed off to Govt. approved vendors.
- Ashes generated from coal used in riveting- Stored and disposed off to Govt. approved vendors.
Quality of Archiving
Each member was assigned a unique identification number.
Progress of work was monitored using MS Project.
Induction of New Technology
Automatic Submerged Arch welding has been used in the welding of members to ensure quality. As much as 185 km of welding has been carried out in fabrication of members in the workshops. Rivets have been used only at the joints of the truss.