High-performance resilient earthquake-resisting moment frames

Abstract

The need for resilient or sustainable seismic design is at the forefront of structural engineering challenges worldwide. Sustainable seismic design is a relatively new concept that is rapidly gaining interest and hints at the arrival of the next generation earthquake engineering practice. In the present context ‘sustainable seismic’ refers to structural operability with a view to post-earthquake realignment and repairs. Experience has shown that it is cost inhibitive to elevate the status of conventional earthquake-resistant structures to seismic sustainability by means of traditional methods of design and construction. This paper introduces two simple analytic concepts, performance control and design led analysis, that lead to the development of sustainable seismic designs for purpose-specific archetypes. Seismic energy control, global stiffness reduction and restoring force adjustment are introduced as relatively simple methodologies that help achieve efficient post-earthquake realignment and repairs. Combinations of structures of uniform response and rigid rocking cores are used as ideal models for sustainable seismic design. Three simple technologies, the replaceable energy dissipating moment connection, the energy-dissipating grade beams and the hybrid rocking–stepping core, are also introduced. Several parametric examples are provided to demonstrate the applications of the proposed methodologies.