GUWAHATI, Jan 27 - The three-lane Saraighat Bridge-II over the Brahmaputra, which is being inaugurated on January 29, is expected to ease the nagging problem of traffic congestion at Jalukbari and Amingaon points. The bridge along with the other components of the project that includes a signal-free crossing at Jalukbari, a flyover at the Hajo Road junction, illumination of the area, among others, has cost an amount of Rs 475 crore. This amount has also covered the escalation in the originally estimated cost of the bridge. The bridge is designed for a life span of 100 years.
The total length of the bridge is 1,493.58 metres and it is resting on 11 wells (piers) and two pile foundations � one at each of the ends on the high banks. The bridge is designed as per the Indian Road Congress (IRC) specification to carry the maximum load.
Eleven piers of the bridge have been provided with special attachments � the shock transmission units � to cope with seismic forces. For the first time in the Northeast such attachments have been used in a bridge. The bridge is the second one in the country to have such attachments.
It has a carriageway width for three lanes, that is 11.375 metres, and a total width of 13.875 metres, which includes a footpath.
Information gathered by this newspaper reveal that the original detailed project report (DPR) and design of the bridge were done by teams of reputed engineers and construction of the bridge started on October 22, 2006, with a tendered 42 months� time for its completion. The work was allotted to M/s Gammon India with an initial tender value of Rs 238.34 crore.
However, the original DPR provisions had to be changed totally to meet the requirement of the prevailing site condition. This is one of the major factors that delayed completion of the project.
Around 2008, certain scope of work like the toll plaza and the grade separator were withdrawn from the project and this reduced the cost to Rs 215.76 crore. But in September 2010, the signal-free crossing at Jalukbari was added to the scope of work. This crossing includes three loops, three ramps, six-lane grade separators and one underpass, besides five bridges.
The flyover at the Hajo Road junction point was also added to the scope of work of the project in January 2014. Moreover, the illumination work, which was not part of the original scope of work, was also added to the project subsequently.
All these raised the total cost of the project to Rs 346 crore without escalation and with escalation the cost rises to Rs 475 crore.
Additional scope of work; the task of sinking the wells much deeper compared to what was envisioned in the original design, due to some inadequacies in the original design; taking additional care for the safety of the existing Saraighat Bridge in sinking the wells in its close proximity; taking care of the safety of the oil pipelines, which are too close to two wells of the new bridge, by introducing additional structures also contributed to the delay in completing the bridge.
The delay in completing the bridge was also caused by the construction of the special structures to sink two wells in the proximity of the National Highway (NH)-31 at both ends of the bridge. These structures were needed for the safety of the approaches to the old bridge.
Further, the slopes of the existing embankments of the NH-31 required to be cut very close to the berm by several metres to accommodate the girder of the new bridge. This called for special attention during casting of the girder. This also retarded the progress of work. The components of the structures as per original design were found to be inadequate in design and hence all the components had to be redesigned and this consumed considerable extra time.
Moreover, due to flood and high current in the river only a few months in a year could be utilised in concreting the structures. The problems of the builders were also amplified by the delay in according permission by the authorities concerned for extraction of the forest products like silt, sand, earth and boulders.
Sources in the know told this newspaper that there are many such hurdles, which obstructed attainment of the desired progress in the originally stipulated time frame.