Experimental study on seismic performance of precast segmental bridge piers with large-diameter grouted sleeve connections

To promote the industrialization of urban bridge construction and satisfy the seismic demands of high-intensity earthquake zones, prefabricated segmental bridges have attracted considerable attention owing to their ease of construction, improved quality control, and environmental sustainability. As a critical component of this system, the seismic reliability of grouted sleeve connection (GSC) directly governs the overall structural seismic performance. However, existing studies have primarily focused on the performance of small or medium diameter GSC, resulting in a lack of systematic understanding of the mechanical properties of large-diameter GSC. Therefore, this study addresses this critical research gap by systematically investigating the seismic performance and failure mechanisms of precast bridge piers specifically utilizing large-diameter (36 mm) reinforcement GSC. The research methodology integrates quasi-static cyclic loading tests on four large-scale specimens with refined finite element (FE) simulations in ABAQUS, examining variables such as longitudinal reinforcement diameter, axial compression ratio, and stirrup ratios to evaluate failure modes and energy dissipation capacity. The results indicate that precast piers with large-diameter reinforcement achieve load-bearing capacities and cyclic energy dissipation comparable to those of cast-in-situ structures, while exhibiting superior initial stiffness. A distinct failure mechanism was identified, in which damage migrates from the conventional plastic hinge at the base to the sleeve top and the bedding mortar interface. This transition is driven by stiffness discontinuity and stress redistribution under high axial loads. Furthermore, parametric analysis confirms that the axial compression ratio is the primary factor governing displacement ductility, whereas optimized stirrup detailing primarily enhances the ultimate load-carrying capacity. This research provides essential experimental evidence and a validated theoretical framework for the safe application of large-diameter GSC, thereby facilitating the reliable deployment of precast pier technologies in high-intensity seismic regions.