Damage Index Distributions in RC Dual Lateral Load-Resistant Multi-Story Buildings Considering SSI Effects Under Bidirectional Earthquakes

Abstract

Inelastic seismic responses of flexibly supported reinforced concrete (RC) moment-resisting frames representing short-to-tall structures stiffened with ductile RC structural walls were evaluated considering both far-field and near-field ground motions. A dual shear wall-frame resisting system with symmetric reference plan was created by adding shear walls into excitation direction of the three-dimensional frames developed by generic structure algorithm. The current study also aims to take into account soil–structure interaction effects in to damage assessment of multi-story RC buildings in terms of ductility demand, damage index, story shear force and overturning moment, as well as kinetic energy profile over the structure height. In doing so, the developed set of generic frames was considered accounting for different values of story strength, stiffness distribution and number of stories. A realistic modeling of nonlinear ductile behavior of RC elements was developed in combination with the sub-structuring method to consider the foundation flexibility in nonlinear seismic responses. Conducting a parametric study through nonlinear static analyses (pushover) as well as nonlinear response history analyses, the results indicated that the near-field ground motion presents much more damage than the far-field one. Inelastic dynamic responses to near-field records demonstrated that structures with a fundamental period greater than the pulse period respond differently from those that have shorter periods. The results were also presented as charts and tables that provide helpful information for engineering design purposes such as damage assessment of multi-story RC buildings with specific fundamental natural period and base shear strength.

Seismic fragility analysis and index evaluation of concrete-filled steel tube column frame-core tube structures

“…To extend the scope of application and compensate for the deficiency in the evaluation using the IDR, the critical IDR and the storey ductility are selected as additional indices to describe the horizontal displacement of the structure. The storey ductility is applied widely to reflect the seismic response of the structure ( Ghayoumian and Emami 2020;Emami and Halabian 2018), and the storey ductility of the ith storey, μ ei , is defined as the ith maximum storey drift divided by the ith yield storey drift. The critical IDR of the ith storey, θ iD , is defined according to the specifications (JGJ 3-2010 2010) as follows:…”

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.…”

“…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.…”

“…Halabian and Emami (2013) concluded that SSI effects could change the height distribution of ductility demand (as a damage measure (DM)) especially for the short and medium structures. They also investigated the SSI effects on the damage index distributions of RC dual lateral load-resistant multi-story structures under bidirectional earthquakes (Emami and Halabian, 2018). Seismic response of reinforced concrete tall structures to the near-fault earthquakes considering the SSI has been investigated by Galal and Naimi (2008).…”