Effect on Super Structure of Integral Abutment Bridge under Fixed and Pinned Pile Head Connections

摘要

Integral bridges are recommended as one of the best alternative in the construction of bridges. They are constructed without joints in superstructure and these bridges can be of single span or multi span. Typically integral bridges have stub-type abutments supported on piles and a continuous bridge deck from one embankment to the other. Failure of proper functioning of the expansion joints and abutment bearings due to various reasons leads to highly critical and serious problems. Failure to move properly due to unanticipated movements results in overstress and subsequent structural damage to the bridge elements via split and rupture of abutment bearings, abutment-rotation and abutment-overturning.An attempt is being made in this study to analyse the effect of pile head connection with abutment on super structure under DL, LL and temperature effects on integral abutment bridge by FEM analysis using SAP 2000. The study considers integral abutment bridge with pile head having fixed and pinned connection with single, two and three spans. The variation of different design parameters such as BM, SF, axial force and longitudinal fibre stresses in deck slab and BM and SF in girder bridges have been analysed and compared. It is found that, in integral abutment bridge the design parameters are affected by the pile head to abutment connection. It is found that, in case of only DL, the negative maximum end BM is reduced by 10.5% in case of single span, 28.5% in two spans integral abutment bridge and no change in three spans integral abutment bridge. However the positive BM shows an increasing trend. It is also observed that the all design parameters are reduced with increase in span numbers. On the other hand, the temperature rise enhances negative BM and decreases positive BM. Furthermore, SF in deck slab is increased by 5.9% in two spans integral abutment bridge having pile head with pinned connection but there is no change in SF is observed in single and three spans, similarly in central girder decrease and in external girder increase in SF is observed in single and two spans bridge and there is no change in three spans bridge. Also DL + temperature and DL + LL+ temperature combination with different spans in comparison with single span and in comparison with DL is studied.