THE SEISMIC PERFORMANCE OF PRECAST BRIDGE PIERS WITH GROUTED SLEEVES

The grouted sleeves embedded in precast column bodies were taken as the research object. The mechanical behavior of the column-to-footing joint and the influence on the overall seismic performance of this kind of bridge piers were theoretically analyzed. A quasi-static test of precast bridge piers with grouted sleeves was carried out. The difference between the seismic performance of the cast-in-place piers and the precast bridge piers with grouted sleeves was compared by a numerical simulation. The influence of different sleeve diameters and lengths on the seismic performance of the bridge piers was also investigated. The results show that the precast piers with grouted sleeves were easy to form a rigid region in the connecting section due to the large rigidity of the sleeves, and that the redistribution phenomenon of the curvature occurred in the columns, resulting in an increase in the curvature and rebar strain concentration adjacent to the end of the sleeves. In addition, the precast bridge piers with embedded grouted sleeves in the plastic hinge area were found to have a reduced displacement capacity as compared to cast-in-place piers with the same reinforcement. This phenomenon was more serious when a larger sleeve diameter was adopted. The larger the diameter and the longer the length of the sleeves, the more obvious the strain concentration at the joint, which resulted in the transformation of the final failure form of the pier from the traditional concrete failure in the plastic hinge area to steel fracture in the joint at the bottom of the pier.