Sustainable Seismic Design of Triple Steel Structures

Abstract

Dual systems composed of steel Moment Frames (MFs) and Eccentric Braced Frames (EBFs) are some of the most popular earthquake-resisting structures (ERSs) worldwide. Triple systems are similar to ERSs but with added hybrid rigid rocking cores (HRRCs) that render the trio sustainable against seismic events. Economy-based Sustainable Seismic Design (SSD) is a new concept with a view to achieving financial benefits and environmental protection. Earthquakes impose the utmost load conditions accompanied by large inelastic distortions of almost all structures. The challenge is always the same: to prevent collapse and attempt repairs. Hence, the aim is to design ERSs with an emphasis on the economy and Post-Earthquake Realignment and Repair (PERR), rather than complying with antiquated guidelines. In conventional ERSs, the aim is to satisfy code requirements, whereas in SSD, the economics and post-earthquake attributes of the system are as important as those during the event. The physical effort involved in PERR is directly affected by the design objectives. SSD is part of neither college curricula nor design guidelines. This article promotes the notion that seismic sustainability (SS) in a structure can be highly economical and environmentally friendly if it can prevent collapse, overcome residual effects, and lend itself to PERR. To gain insight into the inner workings of SSD, this report discusses the principles of performance control (PC), design-led analysis (DLA), and the use of replaceable energy-dissipating devices (REDDs). In conclusion, the main contribution of this paper is that it shows that the conventional design can be upgraded to economy-based SSD without resorting to untenable costs and technologies. All the results have been verified via independent computer analysis.