ER521A – Works at Slip Road from Pan Island Expressway to Airport Boulevard

As part of the efforts to support the development of Changi Airport, the existing slip road from Pan Island Expressway (PIE) to Airport Boulevard has been widened to a three-lane road, enhancing its traffic capacity. The proposed works include the design and construction of a new vehicular bridge and utility bridge across the existing Changi Airport Diversion Canal as well as the associated ancillary works.

Since both the vehicular and utility bridges were constructed across an existing canal which was also to be widened, a comprehensive work process was outlined to ensure the safety of project team. Besides, a tidal gate was devised to prevent sea water from entering during high tight while the dry weather flow was being diverted during different stages of operation.

Before the construction of vehicular bridge, two water pipes of 500 mm and 700 mm in diameter were repositioned onto the utility bridge established with prestressed precast (PSPC) beams, ranging from 20 m to 26 m in length with approximate weights of 80 tonnes to 110 tonnes. Subsequently, three crossheads of 16 m by 1 m were erected to receive eighteen PSPC beams, ranging from 12 m to 26 m in length and 50 tonnes to 60 tonnes in weight, for the construction of vehicular deck slabs with an overall span of 67 m.

At the same time, a stretch of 80 m permanent retaining structure with 12 m cast-in sheet piles and skin wall finishing was formed to cater for the differences in carriageway level while approximately 100 m of Changi Airport’s security fencing was relocated due to the widening works.

Special Feature

• Due to space constraints, the project team had for the first time embarked on a novel non-symmetrical hoisting method to launch the beams for utility bridge.
• As launching of gantry along PIE towards East Coast Parkway and Changi Airport required full lane closure, first-of-its-kind traffic diversion with counter flow was implemented along PIE towards Tampines Expressway.