RETROFITTING OF REINFORCED CONCRETE BEAM-COLUMN JOINTS IN MODERATELY ACTIVE SEISMIC REGIONS

The beam-column joints of older reinforced concrete bridges in seismic regions are often plagued with insufficient development length and insufficient ductility. Retrofit details for beam-column joints are presented that shift the hinge location down the column away from the beam-column interface. Details are developed explicitly for box girder bridges with integral bent caps. By shifting the hinge location, sufficient development length and ductility are provided at the hinge location. The portion of the column above the new hinge location is reinforced to prevent failure. If the column is jacketed at the hinge location, the column hinge moment may cause too large a moment in the superstructure. In order to prevent this from occurring, a reduced capacity jacket section is provided at the column hinge location.