Experimental Investigation Of The Influence Factors On The Seismic Response Of Adjacent Bridge Girders

Damaged bridges, especially due to pounding and unseating at expansion joints have been observed in almost all major earthquakes. They are the result of large relative girder displacements, in excess of the designed gap width and seat length. Research shows that relative displacement of neighbouring bridge segments depends on the fundamental periods of the adjacent structures, spatially varying ground motions and soil-structure interaction (SSI). To evaluate the nature and significance of these influence factors, two identical, scaled, single degree of freedom models were tested using shake tables. The scaled models were designed in accordance with the principles of similitude. The results obtained by isolating and varying each individual influence factor are presented and discussed in this paper.