The bridge consists of 45 intermediate spans of each and a span of at each end. The deck provides for a two-lane roadway for IRC class 70 R loading with footpaths on either side. The cantilever segmental construction method was adopted; each span has two cantilever beams on both sides which are free to move at the ends. It has two lanes, one upstream and the other downstream, each with a width of around. These lanes are free from each other with no connections. It was constructed using pre-cast parts, which were joined at both ends to complete the span. The spans are connected with a protrusion which is free to move longitudinally. Vertical movement allows for vibrations from vehicular movement to transfer smoothly between spans without much discreteness.
Traffic congestion
In recent decades, the bridge has experienced major traffic chaos due to the increasing number of vehicles crossing it, operating in excess of capacity and overloading the structure. The Bihar government has planned to build two pontoon bridges parallel to it, in order to relieve these problems. The bridge is crossed daily by over 85,000 vehicles and 12,000 pedestrians.
Reasons for cost increase: This extra cost is the outcome of an "in-built" cost escalation clause in the contract
Reasons for delay: Heavy storm in April 1979 destroyed two gantries and casting beds. Each gantry crane weighs 300 tonnes. Huge shortage of cement and building material and a workers' strike
Reports: Cement and other building materials stored for this project find their way into Nepal and parts of Bihar
Litigation & arbitration: Disagreement between the contractors and the Government overpayments stalled construction activity. Claims and bills got referred to the Law Department. Final completion date: June 1982 Completion date: April 1987 Total cost: 87 crores Minister of State for Public Works: Raghunath Jha Chief Minister: Jagannath Mishra
The bridge has often been subjected to structural loads and moving loads exceeding its design. Major repairs were initiated on it within five years of its completion. Poor maintenance, coupled with wear and tear caused by the unprecedented surge in traffic, has made the structure vulnerable. Other bridges in India which were built with the same cantilever design have developed cracks. Investigations into the fissures developed in the bridge revealed the following defects: hammering at the hinges when vehicles plied; finger-type expansion joints in an advanced state of distress; wearing coat cracks; spilling of concrete at transverse joints; longitudinal cracks in precast segments; leakage of water inside the box girder from joints between segments and from holes provided for lifting the segments. Mahatma Gandhi Setu is now being revamped. It may have happened that due to such inferior quality of reinforcement coupled with inferior concrete have been causes for such catastrophic failure. Stressed cables are not grouted at all. They are acting like de-bonded tendons. There is minimal stress left. That is why external pre-stressing made later could not make up the stresses lost. Even cables do not conform to the as-built drawings submitted. All as-built drawings say how improper the design was. Providing central hinge bearing may not have given so much of adverse effect as the problems cited above. Now it is becoming clear that there were faults in all the departments, be it design or construction or supervision or material deficiency.
