Effect of Double Plastic Hinges on Seismic Performance of Strengthened Column

The RCC bridge columns are generally severely damaged during disastrous earthquakes. Traditionally, strengthening methods by bonding with steel plate, FRP or other strengthening materials are employed in RCC columns. The deformation capacity is improved for strengthened column, and they can withstand large earthquake due to the energy dissipation effect of the non-elastic phase. The plastic hinge formation is a major factor in the deformation of the column and plays an important role in the seismic performance of the column. Strengthening partial height of column with steel plate and by optimizing the plate thickness, two plastic hinges could be formed simultaneously at two positions, one at the column bottom and other at the upper edge of the strengthening steel plate. A cantilever bridge column of rectangular hollow section is modelled in ABAQUS, and a comparative study on the seismic performance of the unstrengthened and strengthened columns with single and double plastic hinge is done. In the column, the double plastic hinge formation improved the ultimate deformation, stiffness and its strength capacity.