COST OPTIMIZATION OF HIGH-SPEED RAILWAY PRE-STRESSED BOX GIRDER BRIDGE

This paper presents an efficient and reliable computational tool to analyze and reach the optimal design of a high-speed railway pre-stressed box girder bridge. The design and analysis of the simply supported box girder bridge is performed by using CSI bridges and SAP 2000 finite element software according to Eurocode (EN 1991-2, 2003) [5] and the Egyptian Code of Practice (ECP 201, 2012)[3]. Computer spreadsheet applications are developed for design and cost estimation of a full-span precast box girder bridge. The optimal design is achieved by selecting the efficient design variables based on the limit-of-deflection constraint. Development of the optimum design charts was evaluated through cost estimation of all major bridge components, including the foundation and sub-structure. The design variables considered in this study were girder depth, span length and the pre-stressing area. The optimum, i.e. most cost efficient design is attained at a girder depth of 2.9 m, a span length of 32 m and a pre-stressing area of 347 cm2 .