Master's lecture in í Civil Engineering - Hrund Sigfúsdóttir

The lecture will be on Zoom: https://eu01web.zoom.us/j/3548445438

Master's student: Hrund Sigfúsdóttir

Title: Comparison of Force-Based and Direct Displacement-Based methods of seismic-resistant design of structures

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Faculty: Faculty of Civil and Environmental Engineering

Advisor:  Rajesh Rupakhety, Professor at the Faculty of Civil and Environmental Engineering

Other members of the masters committee: Gylfi Magnússon, Senior Engineer at VSO Consulting

Examiner:  Plorin Pavel, Lecturer at Technical University of Civil Engineering, Bucharest, Romania

Abstract

This study compares the force- and displacement-based design of structures. An overview of the two methods is provided with their merits and demerits. The two methods are then used to design two hypothetical structures located in Selfoss, Iceland. The structures being considered are bridges, one having equal pier height and the other having piers of different heights. Since the force-based method relies on initial elastic stiffness of the structure and inelastic effects are indirectly considered through force reduction factors, an iterative scheme is necessary to calculate the design forces. Such iterations can be tedious and can sometimes not converge to the desired performance of the structure. Iterations are also required in the displacement-based design, but since the method is based on secant stiffness of the inelastic structure, the iterations converge easily, and desired performance levels of the structures can be attained.