EFFECT OF TEMPERATURE TO PRESTRESSED CONCRETE BOX GIRDER : CASE STUDY GREEN LINE MRT THAILAND

Abstract

In the present bridge construction, precast segmental box girders are widely used since they can help increase in bridge’s span and reduce construction cost. In Thailand, design of these structures is usually based on AASHTO LRFD-2012 in which the temperature effect used in the State may not correspond to the actual temperature conditions in Thailand. Therefore, aim of this research is to study the effects of temperature gradient at top and bottom surfaces of precast segmental box girder. To measure the actual temperature distribution, the experiment was conducted at the precast factory. The structure subjected to different temperature gradient was also simulated using 2D Finite Element Analysis to predict structural expansion behavior. The analytical stress results due to the actual temperature were compared with those due to the temperature following AASHTO LRFD-2012. It is found that stresses obtained from the standard temperature are more critical than that obtained from the field temperature. Therefore, the temperature according to AASHTO LRFD-2012 can provide sufficient safety to the structures.