The connection behavior of precast prestressed piles to cast-in-place bent caps

Eight full scale single pile specimens representing both interior and exterior portions of bridge bents typical of those used in the state of South Carolina have been tested at the University of South Carolina. Tests were completed to better determine the connection behavior currently in practice within the state. Current construction practices used to make the connection between precast prestressed piles and CIP bent caps involves a plain pile embedment to a depth equal to a single pile diameter with a construction tolerance of +/-6.0 in. (152 mm). Piles with a square cross sectional dimension of 18 in. (457 mm) and lengths of either 16.5 or 18 ft. (5.02 or 5.49 m) were embedded into caps of variable dimensions. Caps dimensions were taken either from a prototype bridge provided by the SCDOT or from caps typical of the Charleston area of the state. In addition to displacement controlled reverse cyclic loading specimens were subjected to either a constant axial compressive load in the case of interior specimens or cyclic axial compressive and tensile loads in the case of exterior specimens. Specimens were created with variable embedment lengths, reinforcement design and were tested a different times following their being cast.;Results of the study show that with a proper embedment length the plain embedment type connection is viable for use in areas of seismic activity and can meet the requirements set forth by the current SCDOT Seismic Design Specifications.