Incremental dynamic collapse analysis of RC core‐wall tall buildings considering spatial seismic response distributions

Abstract

Summary Despite wide‐ranging studies on fragility analysis and collapse safety assessment of short to medium‐rise reinforced concrete (RC) structures, a new interest in the topic is still valuable and even necessary for tall RC buildings. This study aims at establishing fragility relationships as well as collapse probability of high‐rise RC core‐wall buildings under maximum considered earthquake ground motions. This study is carried out in a probabilistic framework on a case study of a fully 3‐dimensional numerical model developed to simulate seismic behavior of a 42‐story building having a RC core‐wall system. Proposing planar and vertical distributions of ductility and damage indices, the incremental dynamic analysis, and the multi‐direction nonlinear static (pushover) analyses were employed to reach the research goal. Median collapse‐level capacities were defined in terms of seismic responses (e.g., ductility/damage indices) as well as several intensity measures by employing statistical analyses and cumulative density functions. Available and acceptable collapse margin ratios were next estimated to quantify collapse safety at maximum considered earthquake shaking level. On an average basis, the statistics indicated 9%–10% and 5%–6% collapse probability of the building subjected to near‐ and far‐field ground motions, respectively.

Probabilistic assessment of plan-asymmetric structures under the near-fault pulse-like events considering soil–structure interaction

“…The shear walls are modeled using panel element combined with fiber model for the axial-bending behavior and nonlinear spring for the in-plane shear behavior. The fiber-based multi-spring model is a useful technique to simulate the columns and shear walls in the similar studies such as Tang and Zhang (2011), Emami and Halabian (2017, 2018), Brunesi et al (2016), and Brunesi and Nascimbene (2017). The out-of-plane behavior is assumed elastic.…”

“…In recent years, the extensive tendency of researchers is oriented to the IDA. Now, the IDA is a traditional tool for the seismic assessment of different structures (Emami and Halabian, 2017; Sadraddin et al, 2016). The IDA is a parametric analysis method to determine the seismic dynamic capacity of structures in different levels of performance.…”

“…Furthermore, the structural damage can be computed for a section, member, story, or structure. But for RC shear-wall structures, the story and global damage indexes (such as story ductility demand or drift and global ductility demand or drift) are traditional damage indexes in the previous studies (Emami and Halabian, 2017, 2018; Halabian and Birzhandi, 2014; Tang and Zhang, 2011). It must be noted that for dual structures that consist of shear walls and moment frames, use of local damage indexes of a shear-wall section (such as plastic hinge rotation) may not be a good representative for CP damage index because of the moment frame (secondary system) action.…”

“…Their results show that an increase in the level of asymmetry in structure leads to an increase in potential of the progressive collapse at both sides of plan in the asymmetric structure. Birzhandi and Halabian (2017) presented an approximate method for the incremental dynamic analysis (IDA) and fragility curves of plan-asymmetric structures. Also Soleimani et al (2018), using a bidirectional energy-based pushover, proposed an approximate twocomponent IDA.…”

“…Therefore, when it comes to record-to-record variability, the present study aimed to focus on the near-fault events due to the shortage of researches compared to the far-field events. In this study, similar to Ji et al (2009) and Emami and Halabian (2017), 10 ground motion records are chosen as the seismic scenario.…”