Risk‐based seismic design for collapse safety

Abstract

Summary Risk‐based seismic design, as introduced in this paper, involves the use of different types of analysis in order to satisfy a risk‐based performance objective with a reasonable utilization rate and sufficient reliability. Differentiation of the reliability of design can be achieved by defining different design algorithms depending on the importance of a structure. In general, the proposed design is iterative, where the adjustment of a structure during iterations is the most challenging task. Rather than using automated design algorithms, an attempt has been made to introduce three simple guidelines for adjusting reinforced concrete frames in order to increase their strength and deformation capacity. It is shown that an engineer can design a reinforced concrete frame in a few iterations, for example, by adjusting the structure on the basis of pushover analysis and checking the final design by means of nonlinear dynamic analysis. A possible variant of the risk‐based design algorithm for the collapse safety of reinforced concrete frame buildings is proposed, and its application is demonstrated by means of an example of an eight‐storey reinforced concrete building. Four iterations were required in order to achieve the risk‐based performance objective with a reasonable utilization rate. Copyright © 2016 John Wiley & Sons, Ltd.

Formulation of risk‐targeted seismic action for the force‐based seismic design of structures

“…In this process, the force‐based design using the proposed approach can provide a very good initial structural configuration. However, in these cases, it is reasonable to assume that the unknown parameters are assumed without any conservatism, as it is easier to define guidelines on how to increase the strength and deformation capacity of the structure (eg, Lazar Sinković et al) rather than how to decrease those parameters of the structure. It has been shown before that by using simple guidelines for adjusting the structure, the risk‐based performance objective could be fulfilled by a reasonable utilization rate when performing only a few iterations.…”

“…Franchin and Pinto and Franchin et al proposed a method for the probabilistic iterative design of reinforced concrete structures using linear elastic analysis. An iterative pushover‐based procedure, which could be used when designing reinforced concrete frames for target collapse risk, has also been proposed . However, the initial design of a structure is of great importance when it is based on the iterative procedure and nonlinear analysis.…”

IM‐based and EDP‐based decision models for the verification of the seismic collapse safety of buildings

“…Modern design procedures should therefore permit to design a building for a specific performance measure expressed in probabilistic terms. Although seismic risk assessment is increasingly being considered for direct or indirect inclusion in seismic design procedures (eg, Haselton et al, Lazar Sinković et al, and Dolšek and Brozovič), it is still challenging to introduce risk‐based design using nonlinear methods of seismic analysis even in the case when the target (acceptable) collapse risk (eg, the target probability of collapse per year) is the only considered performance objective. The reason for this challenge lies not only in the accuracy of the probabilistic assessment of collapse risk, which requires the use of comprehensive nonlinear models of structures, simulations of the seismic response of a building for numerous ground motions, and quite a lot of information about the seismic hazard at the location of a building, but also in the understanding of the problem, since several common false or obsolete beliefs still exist about performance objectives.…”

Demand Hazard Analysis: A Tool for Assessing the Adequacy of Capacity Design Approach for Definition of the Design Shear Forces in the Frame Buildings

“…For example, Lazar Sinković et. all [1] and Lazar and Dolšek [2] recently proposed an iterative design procedure which makes it possible to use different type of analyses (including non-linear), and to control the adjustment of structure during an iterative design. The iterative procedure is currently used for checking the adequacy of collapse risk, whereas other performance objectives are considered according to building codes.…”