KATHMANDU, Feb 13: A loud bang at 2 am roused the locals of Sinamangal from their deep slumber on March 28, 2009. The locals felt their buildings shake. They did not dare to venture out immediately thinking it was a bomb blast. Nobody even tried to open their windows to look out. Then, at around 4, another blast rocked the area.
The locals discovered later in the morning that the bridge built over the Bagmati River at Bhimsengola had collapsed. The bridge, built in 1966, was estimated to last for 100 years.
But the rampant sand extraction from the river led to the weakening of the bridge´s plinth, causing distortion in the middle. As a result, the 40-meter bridge became useless in less than half of its expected lifespan.
Dharma Lama, 52, a resident of Sinamangal, says that the damage had caused great inconvenience to the locals and others who used the bridge every day to go to other places.
PHOTO: BIJAY GAJMER
At the time, the construction of the road network that formed Bagmati corridor had already been under way.
Thousands of commuters and motorists faced difficulties as all the vehicles coming from Old Baneshwar, Buttishputali and east of Sinamangal were diverted to the ring-road.
The officials of the Kathmandu Division Office of the Department of Roads visited the site the following day and concluded that the bridge was beyond repair and constructing a new bridge was the only solution.
Again in 2011, a portion of the Bagmati corridor road near the site, where a new bridge linking Sinamangal with Tilganga was being constructed, collapsed.
The officials at the DoR Kathmandu division say that heavy water flow in the Bagmati swept away the road even as the construction of a foundation for the new bridge.
The heavy water flow during the bridge construction weakened the road´s foundation and led to its collapse.
PHOTO: BIJAY GAJMER
The damage disrupted traffic along 1.5 km road between Old Baneshwar and Tilganga.
Pedestrian´s movement, too, was restricted fearing possible rupture as the land over which the road was built developed multiple cracks. The road was repaired and brought into operation in a week.
Though the Bagmati corridor is in operation at present, the traffic flow along Sinamangal, Gaushala and Old Baneshwar routes get affected when the temporary diversion at Bhimsengola becomes vulnerable during the rainy season as the water level rises in the river.
Though the DoR earlier estimated that the new bridge would come into operation by the end of 2011, completing the work still remains a challenge, officials say.
Officials now hope to complete the construction work by the end of March next year.
We are committed to complete the project soon, says Engineer Dipendra Pandey, in charge of the construction project. The DoR is spending Rs 77 million for the reinforced cement concrete bridges.
´Sand mining has posed long term threat for Sinamangal Bridge and locals´
In charge of the Sinamangal Bridge Construction Project
The construction has not been easy the second time as well. What went wrong?
Following the rampant sand extraction by the squatters residing near the banks of the river, the infrastructure got weak at its base and the bridge collapsed just in 43 years though it was meant to last 100 years.
Before constructing the second bridge, the soil investigation should have been done in more detail. The then official designed the bridge on the basis of the soil survey at Gairidhara, which later proved to be a blunder. The soil is less qualitative to absorb water. As a result, the flood in the river swept away the pillars of the under-construction bridge.
Is the new bridge safe now?
The 9.5 meters wide bridge has one meter footpath on either side. It is the “A” class type which has the capacity to carry 80 ton weight. However, several collapses in the construction sites in the last three years has left us in doubt about its sustainability. The 25 meters long temporary diversion bridge constructed in 2010 collapsed due to soil erosion in rainy season. Similarly, another diversion built over the river is also on the verge of collapse.
Why does the government take no action against the illegal sand extractors?
The DoR itself cannot punish the wrongdoers. We have to seek help of the Metropolitan Police and the District Administration Office. We were unaware about the sand extraction before 2009. The locals should have been proactive in complaining to the authority earlier which would have prevented the damage.
Do other bridges in the capital face similar problem?
The bridge over the Bagmati linking Thapathali with Kupondole had collapsed in the past due to same reason. But later it was built along with several cut off walls that would support the pillars and channel the water flow in the rainy season. Same technique was applied while constructing the Kalimati and Tinkune bridges. Similarly, the bridges along Bishnumati corridor area are also safe now.
Sinamangal Bridge Fact file
Built in 1966 targeting for 100 years
Collapsed in 2009 due to illegal sand extraction
25 meters long temporary diversion bridge collapsed in 2010
Flood in Bagmati sweeps away portion of road near the construction site of a new bridge in April 2011
Government targets to complete a new 40 meters long, 9.5 meters wide bridge in March next year