Erosion threatens Jamuna Bridge

The Jamuna bridge approach road and its guide embankment on the Sirajganj end have come under fresh threats or erosion as the swelling river with strong current has put the western Brahmaputra Right Embankment in danger, water officials said.
Collapse of a major portion of the ‘hard point’ of the Sirajganj Town Protection Embankment on Friday gave a wake-up call to Bangladesh Water Development Board officials, often blamed by locals for misappropriating crores of takas every year in the name of dredging, checking erosion and increasing navigability of the river Jamuna.
‘Not only the town protection embankment’s hard point, but also the Jamuna Bridge and its guide embankment on both sides might be endangered by the river erosion in future,’ said the director general of the BWDB, Abul Kalam Azad while visiting the damaged portion of the key point of the embankment Saturday morning.
He rang the alarm bell for the country’s largest river bridge a day after a 500-ft stretch of the embankment’s hard point caved in, threatening the Sirajganj town along with seven municipalities and a village. Angry local people attacked the local office of BWDB and damaged vehicles, blaming water officials’ negligence and ill-maintenance year after year for the breach in embankment.
Bridge authority assistant engineer Tofazzal Hossain, in-charge of the Jamuna Bridge, however, told New Age, ‘The bridge and its guide embankment are still safe as I saw when I visited the spot today [Saturday].’
If the embankment of the water development board is eroded, the approach road of the bridge may be damaged, causing disruption to communication between Dhaka and the northern region, he said adding that the BWDB would be responsible for that.
Water resources minister Ramesh Chandra Sen also visited Sirajganj on Saturday. He told reporters, ‘If the bridge and its guide bank are damaged, we will sue South Korean firm, Hyundai, which constructed the bridge’
The BWDB director general, who rushed to the spot Friday afternoon, told reporters that it was really difficult to forecast correctly about the Jamuna courses and no need was felt for taking preventive measure at the point for past 10 years as the Tk 223 crore hard point, built by Hyundai of Korea, bears a 100-year guarantee.
As the river course has already changed, the Jamuna guide embankment on the western side may be in danger of erosion any time in future, which finally may affect the bridge, the top water management official warned.
Local people blasted the BWDB for keeping their eyes shut to the damages caused by recurrent floods to a groyne not far from the hard point. During floods in 2003 and 2005, about 1.5km long Sailabari Groyne, 6 km away from the hard point in the downstream, was completely washed away by the Jamuna, affecting the course of the river.
Collapse of the groyne, which was to protect the hard point from strong waves, weakened the base of the hard point and exposed it to erosion.
   ‘The waves directly hit the hard point for change in course of Jamuna as large shoals emerged that intensified the flow. We are trying our best to protect the embankment,’ said M Aminul Islam, the BWDB executive engineer, whose office was attacked by panicked people Friday.
‘The strong current is directly hitting the hard point as the Sailabari groyne went under water in 2005,’ he added.
The official said on Friday that erosion along Sirajganj point exacerbated in the past 24 hours though the Jamuna waters receded substantially.
Although the Jamuna bridge authority constructed about 2.5km long town protection embankment from Ranigram to Motir Ghat in sadar municipal area, the 7.5km western stretch of the Brahmaputra Right Embankment from Motir Ghat to Jamuna guide dam was not covered by concrete blocks and GOTex. Last year, there were erosions at Malshapara and Biara Ghat in sadar upazila and the BWDB did not take any measures to check erosion, locals alleged.
They wanted either BWDB or the bridge authority to take up a permanent project to protect the 7.5-km stretch; otherwise, they warned, the western guide embankment of the Jamuna could be eroded any time, exposing the approach road and even the bridge structure to erosion.
The Jamuna is the main channel of the Brahmaputra, which has the history of changing courses, at least twice in last two centuries. A major bridge along with other structures would influence the course of the unpredictable river further, hydrologists earlier cautioned.
Hyundai Engineering and Construction Company of South Korea built the Jamuna bridge at a cost of Tk 4,000 crore. The bridge was opened to traffic in June 1998, establishing direct road link between Dhaka and the north. Though the builder gave a 100-year guarantee, multiple cracks were noticed in less than 10 years in 2006, which widened later, forcing the authorities to cap train speed to 20 km per hour.
Railway track was not initially planned, but later it was included in the design at the insistence of the then Awami League government.
A government investigation report in January 2008 revealed that vibrations caused by trains and heavily-loaded vehicles led to cracks. Nine trains, including Dhaka-Kolkata direct train, cross the bridge 18 times a day, along with hundreds of heavy vehicles. The Korean company denied any fault in construction as it built the structure on a design by a British firm. The previous military-backed interim government had planned to initiate legal step against the company, but nothing more was heard in this regard.

Courtesy of NewAgebd