China Civil Engineering Construction Corporation (CCECC) has completed the Barseen Bridge at the Dasu Hydropower Project, a 225.2-metre structure that the Water and Power Development Authority (WAPDA) has described as Pakistan’s longest arch bridge.

The bridge, with a 145-metre main arch span, forms part of the relocated Karakoram Highway (KKH) being built under the project. Project information identifies it as a reinforced-concrete cantilever arch bridge, Gwadar Pro reported on Wednesday.

A CCECC representative told Gwadar Pro that the Barseen Bridge is Pakistan’s longest arch bridge by span.

According to project information, the bridge crosses a deep V-shaped ravine near the Indus River, with a valley depth of around 110 metres. The site’s mountainous terrain, geology and seismic conditions added to the engineering challenges during construction.

Sections of the existing Karakoram Highway in the Dasu project area will eventually be submerged by the project reservoir. The relocated alignment is being constructed at a higher elevation to maintain road connectivity.

WAPDA says CCECC is the contractor for KKH-01, a 25.2-kilometre package of the relocated highway.

The authority said this week that the 78-metre Dogah Concrete Arch Bridge had also been completed on the alternative KKH, describing it as the first arch bridge completed on the 52-kilometre replacement stretch.

For mountainous routes, arch bridges can span deep valleys with fewer intermediate piers, which can simplify construction where access to the valley floor is difficult.

The Barseen Bridge features a reinforced-concrete box arch with a catenary profile. Its 145-metre main arch was built by cantilever casting in multiple segments. The bridge has a span arrangement of 62.6 metres, 145 metres and 17.6 metres.

The Barseen Bridge is one of several bridges and tunnels being built along the relocated KKH to preserve traffic flow after the reservoir is filled and during periods of flooding.

As work on the relocated KKH continues, the bridge is expected to help maintain reliable connectivity through the Dasu area once the reservoir is formed, Gwadar Pro's report added.

Credit: Independent News Pakistan (INP) — Pak-China