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Proceedings of the International Conference on
Advances and New Challenges in Earthquake
Engineering Research, Hong Kong Volume
PERFORMANCE-BASED SEISMIC DESIGN OF STEEL MOMENT
FRAMES USING TARGET DRIFT AND YIELD MECHANISM
Subhash C. Goel and Soon-Sik Lee
Department of Civil and Env. Engineering, University of Michigan, Ann Arbor, MI, U.S.A.
ABSTRACT
This paper presents a seismic design procedure based on performance limit states using plastic
mechanism method and the concept of energy balance. In this study, using the concept of seismic force
reduction factor and the displacement amplification factor, the energy balance equation is modified for
the design procedure. A new seismic lateral force distribution based on nonlinear dynamic analyses is
also presented. This distribution is applied to the performance based plastic design procedure for steel
moment frames. The results of nonlinear static and dynamic analyses of an example steel moment
frame designed by using the proposed method are presented and discussed. The results show that the
structure performed well under design level ground motions as intended, with story drifts within the
target limit.
INTRODUCTION
Many studies have shown that building structures designed by modern seismic code procedures are
expected to undergo large cyclic deformations in the inelastic range when subjected severe earthquake
ground motions. Nevertheless, most seismic design codes are still based on elastic methods using
equivalent static lateral design forces. This procedure can result in unpredictable and poor response
during severe ground motions with inelastic activity unevenly distributed among structural members.
Leelataviwat (1998) developed a new performance-based plastic design procedure using the concept of
energy balance applied to a preselected yield mechanism, with adequate strength and ductility. This
study is an extension of the previous study by Leelataviwat (1998). It is well known that force
reduction and displacement amplification factors, intended to account for damping, energy dissipation
capacity as well as overstrength, have important roles in seismic design. However, since the previous
proposed design method (Leelataviwat, 1998) did not consider the above factors as influenced by the
structure period, the method can result in conservative design for long period structures and
unconservative design for low-rise, short period structures.