Robustness improvements for 2D reinforced concrete moment resisting frames: Parametric study by means of NLFE analyses

Abstract

This study develops a 2D computational parametric analysis of ordinary reinforced concrete (RC) frames, located in seismic zone, with the aim to evaluate some design suggestions with respect to their effectiveness in increasing the structural robustness. Specifically, a five‐storey and four‐span 2D RC moment resisting frame is considered, designed in a highly seismic area according to both Italian and European codes. Subsequently, respecting the seismic design code provisions through a cyclic design procedure, some modifications are suggested regarding the layout of the longitudinal reinforcement bars of the beams to exploit the continuity, Vierendeel behavior and influence of the side face reinforcement bars in the beams. For the different modifications, nonlinear finite element pushdown analyses of the whole frames are performed by imposing a monotonically increasing vertical displacement at the point of the column removal in Atena‐2D and considering the presence of the orthogonal framed systems. Furthermore, two different failure scenarios are examined. The numerical force‐displacement capacity curves corresponding to the different proposed design suggestions are investigated and compared. The results have demonstrated the effectiveness in improving the structural robustness of the proposed solutions, especially, of the side face reinforcement bars with respect to both flexural and catenary behavior. The outcomes have also highlighted the compatibility between design criteria of both robustness and earthquake engineering.

Numerical evaluation of Hybrid Deck Bulb Tee (HDBT) as a solution to improve durability of single-span bridges

“…The authors note that any numerical model is always affected by epistemic uncertainties (Miceli and Castaldo, 2023). Epistemic uncertainty analysis (Gino et al, 2021) is not part of this work but is anticipated in future research.…”

“…The Decked Bulb Tee (DBT) beam, an option for prestressed concrete superstructures for bridges, has been used since the 1980 s with minimal changes in materials or fabrication (Grace et al, 2015). New trends in concrete structural design includes the use of more durable materials, like Ultra-high Performance Concrete (UHPC) (Binard, 2017;El-Helou and Graybeal, 2019), and new design approaches in order to improve the durability and resilience of new structures, for example, life cycle analysis, robustness analysis, among others (Siqi et al, 2021;Miceli and Castaldo, 2023).…”

Reliability-based design optimization for seismic structures considering randomness associated with ground motions

“…The source of uncertainty in this study is the external excitation and the structural geometry uncertainties are not considered; therefore, given a pre-determined topology and layout of the superstructure, the dimensions of these structural members can be regarded as deterministic design variables within the framework of the superstructure' s design. However, sometimes epistemic uncertainties do affect the RC structures, which should be considered in the analysis, as explained in [42] . When dealing with rectangular members, their cross-sectional property, such as the moment of inertia (𝐼 𝑍 ), can be formulated by means of the fundamental design parameters, namely, the width (𝐵) and depth (𝐷).…”