Development of a simplified method of analysis and design of controlled rocking columns

Bridge structures are critical components of transportation networks, supporting safety during earthquakes and enabling rapid post‑earthquake recovery. Conventional seismic design prioritizes life safety by preventing collapse and balancing damage and economic considerations. However, ductile design often results in significant damage and residual deformations due to limited self‑centering capability. Emerging low‑damage technologies seek to minimize structural damage, provide self‑centering, and enhance resilience, thereby reducing post‑earthquake intervention and downtime. Controlled rocking systems, which incorporate energy‑dissipating connections between the pier cap, column, and footing, offer a promising low‑damage solution but remain difficult to model in practice. Gap opening and closing at the rocking interface is not explicitly supported in most commercial software. While finite element models can capture this behaviour, they are computationally expensive for routine use. Macro models are more efficient but require specialist expertise and are not easily implemented in standard bridge analysis platforms. This dissertation develops a practical framework for the analysis and design of dissipative controlled rocking bridge columns and systematically compares their performance with conventional earthquake resisting systems. A Modified Beam Theory–based Simplified Analytical Method for rocking columns is formulated, together with a compatible three‑spring model for rocking connections implemented using General Link elements in Midas Civil. These models are calibrated and validated against numerical datasets and existing experimental results. The research establishes practical design guidelines and Excel/VBA tools for backbone generation and for sizing post‑tensioning tendons and energy dissipators, and proposes preliminary procedures for response modification factors R and elastic stiffness‑reduction factors α. Seismic performance is evaluated and compared for dissipative controlled rocking, ductile reinforced‑concrete, lead rubber bearing, and friction pendulum bearing systems for prototype highway and LRT bridges, including soil–structure interaction. Serviceability and vibration performance are compared for dissipative controlled rocking and ductile reinforced‑concrete systems with reference to CHBDC/NBCC and Eurocode passenger comfort criteria. The results show that dissipative controlled rocking bridges can achieve reduced base shear and foundation demands, negligible residual drift, and low damage while meeting code requirements. The validated framework and design toolbox provide office‑ready tools that support broader adoption of controlled rocking columns, including in Accelerated Bridge Construction.