Design and construction of a hybrid double-skin tubular arch bridge

A novel double-skin tubular arch (DSTA) bridge system is being developed at the University of Queensland as a collaborative effort of several organizations. This new bridge system builds on the existing research on hybrid double-skin tubular members (DSTMs) which consist of an outer FRP tube, an inner steel tube and a layer of concrete sandwiched between them. DSTA bridges are light-weight, durable, of low-cost and rapid to construct, thus providing a highly attractive alternative to traditional bridge systems. This paper presents the design and construction of a full-scale DSTA bridge prototype in the laboratory. The design procedure based on existing design provisions for DSTCs is briefly presented. The construction process of the DSTA bridge, including the fabrication of steel and GFRP segments, assembly process, fabrication of joints and concrete casting, is described in detail and discussed. Two methods for the fabrication of GFRP joints, namely the wet-layup process and the pre-preg process, are described and compared.