Publications

Concrete foundations in seismic regions are usually designed to withstand plastic hinge moments that can be developed at the bases of the columns. These hinges are used to eliminate the moments transferred to the foundations. The ratio adopted by the American Concrete Institute (ACI) to determine the amplification of the strength of the hinge due to confinement effects, is limited to two. This paper presents the experimental analysis conducted on several two-way hinges to assess their behavior on concrete structures with specific focus on the amplification factor. The main parameters used in this investigation are the square root of the column area over the hinge area, and the overall hinge strength due to vertical throat concrete crushing failure mode. It is expected that the results of this study will lead to the development of guidelines for the behavior of two-way hinges in reinforced concrete structures.