Probabilistic Seismic Assessment of Moment Resisting Steel Buildings Considering Soft-story and Torsional Irregularities

Razmkhah, Mohammad Hossein; Kouhestanian, Hamed; Shafaei, Jalil; Pahlavan, Hossein; Amiri, Mohammad Shamekhi

doi:10.5829/ije.2021.34.11b.11

Cited by 4 publications

(3 citation statements)

References 12 publications

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“…To identify the nonlinear behavior produced by the ground motions and to determine the variables of the conditional probability distribution of the demand measure, data from a total of 192 analyses were collated (i.e., pier ductility and the girder displacement). When predicated on the intensity measure, the demand measure data are considered to follow a lognormal distribution [19]. While the conditional demand dispersion is constant, the conditional mean of the given demand and (PGA) was linear in log-log space [20].…”

Section: Methodology For Fragility Functionmentioning

confidence: 99%

Probabilistic Damage Analysis of Isolated Steel Tub Girder Bridge Excited by Near and Far Fault Ground Motions

Baig

Ansari

Islam

et al. 2023

IJE

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Friction Pendulum Bearing (FPB) has emerged as a popular solution for damage protection of bridges under seismic events. The study presents the probabilistic damage analysis for the isolated tub girder continuous bridge under the near and the far fault earthquakes using fragility analysis. The steel tub girder continuous bridge is considered with friction pendulum isolator as the seismic isolation mechanism. In order to represent the hysteretic behavior of friction pendulum isolators, a bilinear forcedeformation model was used. Fragility curves are developed for various damage measures namely rotational ductility of pier and girder displacement with the peak ground acceleration (PGA) as an intensity measure (IM). Incremental dynamic analyses (IDA) were performed to develop the fragility curves and probabilistic damage model considering the four threshold damage states. The results suggest that in the case of low PGA level, the near fault earthquake leads to the high probability of exceedance in the case of isolated tub girder bridge. Damage model for piers and girder were developed to correlate component responses levels to overall bridge deterioration states. Finally, recommendations for the bridge developers in the stage of the early bridge seismic isolation design utilizing friction pendulum isolators are discussed.

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Section: Methodology For Fragility Functionmentioning

confidence: 99%

Probabilistic Damage Analysis of Isolated Steel Tub Girder Bridge Excited by Near and Far Fault Ground Motions

Baig

Ansari

Islam

et al. 2023

IJE

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“…Razmkhah et al investigated the fragility curve for the steel moment frame seismic system and indicated that the damage state of the structure due to soft story irregularity was decreased with increasing stories. On the other hand, the damage caused by torsional irregularity in plan was increased by increasing the structure's height [6].…”

Section: Introductionmentioning

confidence: 99%

Probabilistic Evaluation of Seismic Performance of Steel Buildings with Torsional Irregularities in Plan and Soft Story under Mainshock-Aftershock Sequence

Kouhestanian

Razmkhah

Shafaei

et al. 2023

Shock and Vibration

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Due to the tectonic plate movement, numerous aftershocks may occur following an earthquake. There are several real mainshock-aftershock ground motion records in which the peak ground acceleration of aftershock is greater than that of the mainshock. Furthermore, irregularities such as soft story and torsional irregularity may change the structural behavior under the influence of earthquakes. This study investigates the fragility curves associated with the three-, five-, and eight-story models with steel moment-resisting frames under the main earthquake and mainshock-aftershock sequence to probabilistically evaluate the aftershock impacts on the steel structures with irregularities in the plan and height. The seismic fragility curves were calculated for four damage levels by selecting the relative displacement capacity at seismic performance levels of slight, moderate, extensive, and complete damage from the US HAZUS code. The analysis was done using structural reliability relationships and incremental dynamic analysis with the OpenSees software platform. The analytical results showed that the structures with soft-story and torsional irregularity were more vulnerable with an increasing number of stories. Also, aftershocks were found to have a more destructive effect on low-rise models. The probability of structural collapse in a given peak ground acceleration for a damaged state due to the mainshock-aftershock sequence is higher than that of the mainshock sequence.

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“…Examples of application of reliability analysis in building structures include prediction of flexural behavior of beams subjected to pitting corrosion [5], evaluation of shear strength of deep beams with and without web reinforcement [6], torsional design of reinforced concrete beams strengthened with CFRP laminate [7]. The list also includes assessment of existing reinforced concrete beams when strengthened with additional reinforcing bars [8], evaluation of bearing capacity of slabs considering compressive membrane action [9], structural fire safety assessment of slabs exposed to fire [10], reliability analysis of seismic hazard [11], seismic assessment of buildings with soft-story and torsional irregularities [12]. As a contribution to the trend of reliability-based design, the present paper discusses a probabilistic procedure for evaluation of flexural strength of a statically indeterminate reinforced concrete beam considering the effect of moment redistribution.…”

Section: Introductionmentioning

confidence: 99%

Probabilistic Assessment of Bending Strength of Statically Indeterminate Reinforced Concrete Beams

2022

IJE

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This paper presents a reliability analysis of a two-span reinforced concrete beam, taking into account of random variations in cross-sectional dimensions, area and position of reinforcement for sagging and hogging bending moments, material strengths, loads and model uncertainties. In addition, the limit state functions for the statically indeterminate beam were derived; considering the static equilibrium requirement after the moments were redistributed as well as the codified allowable limit for the adjusted moment at each beam section. A large number of Monte Carlo simulations were performed in which the basic variables were modeled with normal, lognormal and Gumbel distributions. When the elastic moment distribution was used in evaluating the beam reliability, the two-span beam behaved as a series system with three critical nodes located at the interior support and midspan sections. The probability that the system had at least one overloaded node was greater than the failure probability of an individual node. However, considering moment redistribution made it possible to reduce the amount of reinforcement whilst maintaining the reliability of the beam. When the reinforcement area was reduced by 26% at the support section or 14% at the midspan sections, the failure probability was predicted to be 6.9010 -5 , which is deemed acceptable for a 50 year reference period.

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Probabilistic Seismic Assessment of Moment Resisting Steel Buildings Considering Soft-story and Torsional Irregularities

Cited by 4 publications

References 12 publications

Probabilistic Damage Analysis of Isolated Steel Tub Girder Bridge Excited by Near and Far Fault Ground Motions

Probabilistic Damage Analysis of Isolated Steel Tub Girder Bridge Excited by Near and Far Fault Ground Motions

Probabilistic Evaluation of Seismic Performance of Steel Buildings with Torsional Irregularities in Plan and Soft Story under Mainshock-Aftershock Sequence

Probabilistic Assessment of Bending Strength of Statically Indeterminate Reinforced Concrete Beams

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