Upper Serangoon Viaduct Singapore
TDV was approached by the Swiss Consulting Engineers Höltschi & Schurter from ZÃ¼rich to assist in this project.
The Main Contractor who had been awarded the Contract approached BBRV, the prestressing cable supplier, who approached HÃ¶ltschi & Schurter to produce an alternative design for this viaduct.
TDV acted as conceptual Consultant in the preparation, planning and design of the complete construction stage bridge erection procedure. The erection procedure was greatly complicated by the Clients requirements of no interference with the existing traffic flow in the area.
The bridge concept for the "Upper Serangoon Viaduct" comprises cast-in-situ twin box girders supported on a single central pier (in the transverse direction).
The viaduct is divided into four parts. Each part acting as a continuous structure over eight or twelve spans. The length of one typical span is between 34.20 m and 36.50 m. The height of the concrete box girder in a typical span is a constant 2.20 m. The spans at the two crossings are 70 m and 50 m where the maximum height of the concrete box girders is 3.0 m at the pier.
The chosen erection procedure resulted in two different construction methods being chosen for the construction of the viaduct. The typical spans being built on a launching truss (â€˜span-by-spanâ€™-method), and the two crossings being built using the balanced cantilevering method. Each bridge part acts as a continuous structure.
The bridge model, which was generated by the pre-processor program RMGEOP, includes the alignment in the horizontal plane resulting in a 3-dimensional structural analysis.
The effects of creep and shrinkage using the CEB-FIP model code assumptions, which are implemented in the software, were carefully considered for the various construction stages.