ICE Malaysia Webinar: Alternative design and construction of DASH CB1 Mainline long span bridge

Overview

Tony Gee was engaged by the main contractor, Acre Works, to produce an Alternative Design for a special span segmental box girder bridge forming part of Package CB1 on the DASH Expressway project in the suburbs of KL. The structure is a four-span prestressed concrete twin box girder bridge with a maximum span of 82.3m and maximum height of 32.8m above ground level necessary to clear not only a grade separated interchange but also an existing MRT viaduct below.

The segmental structure was constructed in-situ by the balanced cantilever method using form travelers. The alternative proposal demonstrated a material saving of up to 30% and reduced the number of piles from 37 in the conforming design to 24. The cross-section of the viaduct was also re-engineered for ease of form traveler erection and reinforcement by changing the original tapered web to vertical.