SHEAR STRENGTH AND DEFORMABILITY OF RC BRIDGE COLUMNS SUBJECTED TO INELASTIC CYCLIC DISPLACEMENTS

Many reinforced concrete bridges designed prior to the establishment of modern fundamentals of earthquake resistant design are vulnerable to damage and collapse in earthquakes. Failures have often been associated with inadequate column shear strength. Fundamental concepts of shear strength are discussed. Column damage to California bridges in previous earthquakes is reviewed. Bounds on the shear strength of damaged bridge columns are calculated using available data on construction details and failure mode. Research on column shear strength is reviewed. A simplified expression for the assessment of the concrete contribution to shear strength is developed for use in evaluation of existing bridge structures. An approach to the evaluation of column shear strength adequacy is discussed.