Abstract:
The aim of this research was to develop a guidance in selecting type of superstructure of Thai's flyover in respect with cost,dead weight, depth of member and duration of construction work. Three types of main structural forms of superstructure of flyovers were studied, i.e., concrete slab with steel girder, concrete slab with prestressed concrete girder and concrete box girder are examined. Assessment had been made by studying the data of the projects belongs to Government and choosing the ones that might not be last long 10 years. Quantities of material used were taken into account comprising also the unit cost of materials and construction cost as well as the method statements in each type of structure. The cost of flyover, dead weight and depth of structural members were investigated and compared in competitiveness based on economical and engineering aspects. The result reveals that there are much differences on cost, dead weight, depth of structure and construction time in each type of structural form. The concrete slab with steel girder is the most expensive flyover but performs the lightest dead weight among the others. The construction time is considering moderate. Concrete box girder has the least depth while the price and dead weight are found moderate. In addition, the construction time is found be highest. Concrete slab with prestressed concrete girder exhibits the heaviest dead weight but the price is found be lowest while the construction is shorter than those of the two types.