Dissertation Defence: Development of a Simplified Method of Analysis and Design of Controlled Rocking Columns

Mohammad Saifuzzaman, supervised by Dr. Shahria Alam, will defend their dissertation titled “Development of a Simplified Method of Analysis and Design of Controlled Rocking Columns” in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Civil Engineering.

An abstract for Mohammad Saifuzzaman’s dissertation is included below.

Examinations are open to all members of the campus community as well as the general public. Please email shahria.alam@ubc.ca to receive the Zoom link for this exam.

Abstract

Bridge structures are vital components of transportation networks, ensuring safety during seismic events and supporting economic recovery after a post-earthquake. Modern seismic-resistant design practices prioritize life safety by preventing collapse and balancing economic considerations, ranging from minimal to extensive damage. A key aspect of earthquake-resistant design is the dissipation of seismic energy, which is achieved through methods such as incorporating ductile elements, base isolation systems, or controlled rocking mechanisms with energy-dissipating components. While ductile design allows structural members to deform without significant loss of load-carrying capacity, it often results in damage and a lack of self-centring capabilities post-earthquake.

Emerging low-damage seismic design technologies aim to minimize structural damage while enabling self-centring, thereby enhancing resilience and reducing the need for post-earthquake intervention. Controlled rocking systems, incorporating dissipative connections between the pier cap, column, and footing, facilitate rapid restoration of bridge functionality. However, modelling the gap opening/closing mechanism of rocking columns remains a challenge, as most structural analysis software lacks explicit features for this phenomenon. While continuum-based finite element modelling (FEM) offers accuracy, its computational demands make it impractical for routine engineering applications. Macro models, such as multi-spring models (MSM), provide a computationally efficient alternative but require specialized knowledge and software for parameter tuning and integration into commercial platforms like SAP2000.

Currently, no simplified method exists for analyzing and designing dissipative controlled rocking (DCR) columns, nor is there a comprehensive comparison of their seismic performance against traditional earthquake resisting systems (ERS). This dissertation addresses these gaps by proposing a simplified 3-spring model (3SM) for analyzing and designing DCR columns using bridge analysis software such as Midas Civil. The research also evaluates the seismic performance of DCR columns relative to traditional ERS, offering insights into their cost-effectiveness and adaptability to Accelerated Bridge Construction (ABC) techniques. By providing a practical framework for engineers, bridge owners, and the construction industry, this study aims to advance resilient and economical solutions for seismic-resistant bridge design.