Seismic Performance of Circular Reinforced Concrete Columns Under Varying AxialLoad

摘要

The behavior of four circular reinforced concrete bridge columns, with differentaxial load regimes, is investigated. The first unit was tested under constant compressive axial load corresponding to an axial load ratio of 0.35. The second specimen was subjected to a constant tensile axial force equivalent to 0.087 axial load ratio. Two specimens were tested under varying regime of axial load, ranging between the two previous load limits, in oreder to simulate realistic seismic conditions of outer columns of multi-column bents. Column performance, for compressive axial load, agreed well with UCSD sheer strength analyses. A small modification is proposed to the UCSD shear models for columns under tensile vertical loads. Extended comparison between experimental and predicted shear response, from different current equations, is provided.