Kualanamu International Airport
MEDAN TO KUALA NAMU AIRPORT DOUBLE TRACK RAILWAY LINE PROJECT
The double-track railway will stretch for 26 km and some parts of the railway would be elevated to prevent traffic congestion in Medan. The new railway will shorten travelling times from downtown Medan to Kuala Namu Airport, which will handle continual two-way traffic, and will save at least 10 minutes off the current 30 minute journey time.
The project is the first segmental box girder in Medan, which requires high-end technology in the hands of Wijaya Karya Tbk. since it is built above the existing active railway line. As a main contractor, WIKA BETON Tbk. works closely with the Main Contractor to ensure that the project will be completed effectively on a 'fast-track' program by supply precast segmental box girder used for main span in upper structure.
The height of one box girder segment is 2.4 m and the width is 10.3 m. The maximum weight of a segment is 40 ton. The height of a typical main span is 40 m which requires 15 segments for one span. The total number of precast girder segment is 2974 pieces. Those are produced by Wika Beton’s temporary factories in Tembung-Medan by using single line precast segment production system.
Since the bridge is constructed in a well-known busy railway traffic line area, the Contractors adopted an innovative approach of bridge segment installation for the upper structure. This innovation not only ensure that the project will be completed as scheduled, but also introduce cost savings as a result of the reduction in construction complexity.
The erection of box girder employs span by span method. Box segment is begun at one pier and constructed continuously by placing segments to the other end of the bridge. The segments are positioned by using an assembly truss (launching truss). Before the segments are placed, the launching truss is braced over two piers. Then, the segments are transported by low-bed trailer to the span under construction. Each segment is lifted and placed into its position. Once all segments are in their position, the pier segment is placed.
The final stage is begun by running longitudinal prestressing tendons through segments ducts and prestressing the entire span. After the span is complete, the assembly launching truss is lowered and moved to the next span where construction cycle begins until the bridge is complete.
Since there is no area to stock the segments on project site, all delivered segments should be installed in the planning bridge position directly after the segments arrive at the site. To avoid railway traffic, all segment installations should be done during window time given by railway operator.