Kathmandu, October 13
Both the old and new motorable bridges over Kolpu Khola on the Galchhi-Trishuli-Mailung road were damaged by the August 26 flood, disrupting a key route connecting Dhading and Nuwakot with Rasuwa.
The bridges, which were both in regular use, connect Belkotgadhi Municipality-5 in Nuwakot with Galchhi Rural Municipality-8 in Dhading.
Kolpu Khola is a steep stream that joins the Trishuli River. The road and bridges lie close to the riverbank. The older, smaller bridge has tilted towards the Trishuli River, while the flood surge separated the approach slab from the abutment of the newer bridge.
Restoring the newer and larger bridge was considered essential to maintaining regular traffic along the route. The bridge is an 11-metre-wide, 41-metre-span prestressed concrete girder bridge weighing approximately 900 tonnes.
A team of engineers is now working to push the displaced structure back into its original position without halting traffic.
Jalap Nepal Pvt Ltd, based in Bharatpur, Chitwan, secured the federal government’s contract to repair the bridge. Since September 21, a team led by mechanical engineer Abdul Khalid has been working to reposition the structure, which was shifted from its original alignment by the flood.
Khalid, who is from Taulihawa in Kapilvastu, said the high-velocity flood in the Trishuli River on August 26 caused water to surge into Kolpu Khola and flow backwards for nearly three kilometres upstream for a period.
“When the water began returning to its original direction, the returning flow lifted the bridge slightly. As a result, the bridge shifted 500 millimetres downstream,” Khalid said.
He explained that bridges have stoppers at all four corners to prevent excessive lateral movement. These stoppers prevented the bridge from moving any farther, but the structure’s entire load then rested on them.
“We have already brought the bridge back to a level position. We are now lifting it upwards,” he said.
According to Khalid, Kolpu Khola also acted like a reservoir during the flood. Although the accumulation of water in the stream damaged the bridge, it helped protect the Mahesh Khola bridge farther downstream by holding back some of the floodwater.
Khalid said repairs to the new Kolpu bridge were expected to be completed before Dashain.
Ten Nepali technicians, including Khalid, are currently working on the project.
