A VARIETY OF CHALLENGES LEADS TO A VARIETY OF SOLUTIONS
HSL’s WPC 7 of the highway is among the most challenging. It involves 18 bridges, including a bridge across the Batang Rajang, which is Malaysia’s longest river.
WPC 7 includes two interchanges: a flyover near Julau, and another flyover for seamless travel between Sibu Airport, the town centre and towards Bintulu. The latter interchange is being built in four phases, requiring careful traffic diversion.
There are also 79 bus shelters, seven pedestrian bridges and one lay-by across this span of 76km – all requiring precision engineering and calculations to build.
doubling durin bridge
Durin Bridge, which spans the mighty Batang Rayang, opened in 2006 with two lanes. Because it is an integral part of the Pan Borneo Highway, the bridge is being expanded to accommodate twice the amount of traffic.
HSL’s WPC7 includes creating a new bridge structure that runs parallel to the 1.9km existing bridge.
To achieve that, new support columns are being constructed at the existing piers, without interrupting the flow of traffic.
Senior project manager Philip Lau explains:
“It’s not often you see bridges like this here. Maybe in China, it’s common. Not here. For this bridge, we are using a method called ‘incremental launching’. There are a total of 16 pile caps that provide the new road section with its stability, drilled right into the banks of the Rajang River. The concrete mat layers are then filled up using special ‘hammerhead’ building casts, creating the structural columns for the new bridge portion.
“Once it’s set, we push it outwards to meet the four piers in the river.”
Safety officers also ensure that motorists are able to use the bridge safely as work continues.
In WPC7, some 4.04mil cubic meters of terrain need to be cut, while earth-filling will total 4.8mil cubic meters. As for road construction, aggregates amount to 2.2million metric tonnes.
A HSL subsidiary is also building a new premix plant as the quality requirement for Pan Borneo Highway is high. This new plant will create batch-mix premixes, and will operate alongside the subsidiary’s existing drum-mix plant near Sibu.