Seismic performance of a precast bridge pier with a novel externally assembled 3U energy dissipator (EA3UED): Experimental and analytical study

Precast Bridge Piers (PBPs) face challenges such as insufficient energy dissipation, flexure-shear coupling with complex load transfer, reducing their seismic resilience. This study introduces a novel External Assembled 3U Energy Dissipator (EA3UED), designed to overcome these inherent limitations and enhance the seismic performance of PBPs. The EA3UED is attached using a unique steel band to the pier, comprising three U-shaped components of high-strength steel. It provides multi-directional resistance and allows for post-earthquake inspection and replacement, offering a cost-efficient and maintainable solution. Experimental tests were conducted to evaluate the effectiveness and compare the seismic performance of PBPs with and without EA3UEDs. Additionally, simplified analytical solutions were proposed to derive the initial, yield, and ultimate capacities, showing a good agreement with experimental data and proving effective for preliminary design and optimization. Results demonstrated that integrating the EA3UED on PBPs significantly enhances their seismic resilience. Compared to the conventional precast pier (P-NED), the EA3UED-equipped pier (P-EA3UED) exhibited improvements in lateral load capacity (28.03%), energy dissipation (86.88%), stiffness (30.0%), and residual displacement (64.54% reduction). The primary failure mode in P-EA3UED was yielding of the U-shaped component with less damage bottom column, while P-NED failed with severe damage in the lower column region. The EA3UED’s adaptable design suits both precast and new construction applications and offers a cost-effective solution, particularly in high seismic zones. The EA3UED integration on PBPs using the unique steel band improves seismic resilience without compromising constructability or cost-efficiency. This study confirms the EA3UED as a promising enhancement for seismic-resistant bridge design, contributing to safer and more resilient infrastructure.