Experimental study on the reinforced concrete pile-cap with a pile, exterior column and foundation beam

Recently, the shear failure mechanism of a pile, exterior column-beam pile-cap in Reinforced Concrete (RC) structure is not resolved yet under bi-lateral loading. This report is a series study of grasping the seismic capacity of interior pile-caps, these specimens were carried out to investigate the pile-caps shear performance. The specimens were previously tested in references. The specimens which were the exterior subassemblages of a precast pile, foundation beam and column, were half scale to actual frames. In this experimental study, fourteen specimens were fabricated which can be divided into some types considering the arrangement properties. The ultimate shear strength can be estimated by the prediction method for usual RC beam-column joints [reference 1] to apply the vertical member section to the average between the pile, the column and the pile-cap section or that between column and pile-cap. The shear strength of pile-caps was enhanced by confining effect due to the shear reinforcement amount and the transformation of the surrounding structural members were restrained by them. The difference in the positive and negative maximum strength was occurred by the strut mechanism in loading direction. Finally, the new design formulas have been proposed.