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Papers by Aliakbar Yahyaabadi

Research paper thumbnail of Determination of Structural Fragility Curves of Various Building Types for Seismic Vulnerability Assessment in the Sarpol-e Zahab City

Journal of Seismology and Earthquake Engineering, Oct 1, 2018

Research paper thumbnail of Simulation of cyclic response of precast concrete beam-column joints

Computers and Concrete, Sep 1, 2019

Research paper thumbnail of Development of seismic fragility curves for precast concrete frames with cast-in-situ concrete shear-walls

Earthquake Engineering and Engineering Vibration, 2022

Precast reinforced concrete buildings have been well received in some seismic zones worldwide due... more Precast reinforced concrete buildings have been well received in some seismic zones worldwide due to advantages such as the ease and the speed of implementation, and the possibility of working in inappropriate atmospheric conditions. In this research, seismic fragility curves were developed for precast concrete frames with a cast-in-situ concrete shear-wall, concerning the important issues of modeling the precast beam-column joints, construction quality, and soil type effects. For this purpose, the incremental dynamic analysis (IDA) was conducted for three-dimensional models of 3-, 5-, and 8-story buildings under two record sets corresponding to soil types C and D of the NEHRP code. Beam-column joints were modeled using nonlinear rotational springs with rigid links with respect to the finite size of the joint panel. Results demonstrate that the Weibull distribution can be fitted to the damage state capacities better than the lognormal distribution at the intensities that are more th...

Research paper thumbnail of Introducing a New Scaling Method for Near-Fault Ground Motions Based on the Root-Mean-Square of Spectral Responses

Research paper thumbnail of Nonlinear Dynamic Analysis of Structures Under Near-Fault Ground Motions Using an Improved Scaling Method

Assessment of the seismic performance of a structure often requires conducting nonlinear dynamic ... more Assessment of the seismic performance of a structure often requires conducting nonlinear dynamic analyses under a set of ground motion records scaled to a specific level of intensity using an appropriate scaling method. In this study to reduce the variability in the seismic demands, a seismic-intensity scaling index is developed through studying weaknesses and strengths of different scaling methods. Results of the incremental nonlinear dynamic analyses of generic frames with 3, 6, 9, 12 and 15 storey under 40 near-fault ground motions show that using root-mean-square value of pseudo spectral accelerations over effective period range of structures can considerably reduce the scatter in the dynamic responses particularly once higher modes and period elongation effects dominate the response. By using this scaling method, the amount of dispersion is nearly independent of the ductility demand level and the number of stories.

Research paper thumbnail of ارائه مدل غیرخطی برای رفتار اتصالات خارجی تیر به ستون در ساختمانهای پیشساخته بتنی

Due to the increasing demand for housing, various communities are using the technology and advanc... more Due to the increasing demand for housing, various communities are using the technology and advanced equipment to build housing. Precast RC frame system is one of the methods used for this purpose. The most important features of this structural system are the high quality of construction due to the manufacturing of parts in the factory, the ease and speed of implementation, thus reducing the time gap between investment and utilization, also the possibility of working in poor atmospheric conditions. One of the important points in the implementation of precast concrete structures is how to connect the precast elements of the beam to the column, which will have a significant effect on the seismic behavior of these structures. In this paper, we have tried to estimate the seismic behavior of these structures using the behavior of some experiment specimens of precast joints, which are close to the executable details in Iran. To do this, a numerical model has been presented to consider the ...

Research paper thumbnail of Assessment of Structure-Specific Intensity Measures for the Probabilistic Seismic Demand Analysis of Steel Moment Frames

Arabian Journal for Science and Engineering

Research paper thumbnail of Bayesian probabilistic seismic hazard analysis with respect to near-fault effects

Asian Journal of Civil Engineering

Research paper thumbnail of Probabilistic seismic demand analysis of steel moment frames by utilising Bayesian statistics

European Journal of Environmental and Civil Engineering

Research paper thumbnail of Nonlinear Dynamic Analysis of Structures Under Near-Fault Ground Motions Using an Improved Scaling Method

Asian Journal of Civil Engineering

Assessment of the seismic performance of a structure often requires conducting nonlinear dynamic ... more Assessment of the seismic performance of a structure often requires conducting nonlinear dynamic analyses under a set of ground motion records scaled to a specific level of intensity using an appropriate scaling method. In this study to reduce the variability in the seismic demands, a seismic-intensity scaling index is developed through studying weaknesses and strengths of different scaling methods. Results of the incremental nonlinear dynamic analyses of generic frames with 3, 6, 9, 12 and 15 storey under 40 near-fault ground motions show that using root-mean-square value of pseudo spectral accelerations over effective period range of structures can considerably reduce the scatter in the dynamic responses particularly once higher modes and period elongation effects dominate the response. By using this scaling method, the amount of dispersion is nearly independent of the ductility demand level and the number of stories.

Research paper thumbnail of Studying Rooftop Damper Frame in Braced Structures under near and far field Earthquake Excitations

Rooftop tuned mass damper frame; linear dynamic analysis; nonlinear dynamic analysis; near field ... more Rooftop tuned mass damper frame; linear dynamic analysis; nonlinear dynamic analysis; near field earthquakes; far field earthquakes

Research paper thumbnail of Development of an Improved Intensity Measure in Order to Reduce the Variability in Seismic Demands Under Near-Fault Ground Motions

Journal of Earthquake and Tsunami, 2012

Intensity measure (IM) which describes the strength of an earthquake record plays an important ro... more Intensity measure (IM) which describes the strength of an earthquake record plays an important role in the seismic performance assessment of structures. An improved IM that can reduce the variability in seismic demands helps reducing the number of records necessary to predict the seismic performance with sufficient accuracy. In this study, an improved RMS-based IM is developed based on the results obtained from incremental dynamic analyses of short-to relatively long-period frames under an ensemble of near-fault pulse-like earthquake records. It is observed that the root-mean-square value of pseudo spectral accelerations, (Sa) rms , is generally superior to that of spectral velocities, (Sv) rms , in seismic demand prediction under near-fault records. To compute (Sa) rms as IM, two appropriate period ranges are suggested for short- and moderated-to relatively long-period frames, respectively. Comparing the efficiency of (Sa) rms with several advanced IMs shows that (Sa) rms is more e...

Research paper thumbnail of New scalar intensity measure for near-fault ground motions based on the optimal combination of spectral responses

Scientia Iranica, 2011

ABSTRACT Intensity Measure (IM), characterizing the strength of an earthquake ground motion, is u... more ABSTRACT Intensity Measure (IM), characterizing the strength of an earthquake ground motion, is used to predict the seismic responses of a structure. Recent studies have demonstrated that using Sa(T1) as the seismic scaling index for near-fault ground motions may introduce large variability in the estimated seismic demands. To develop an improved IM, this paper investigates the effectiveness of a large number of combinations of spectral values in reducing scatter in the estimated maximum interstorey drift ratios. For this purpose, Incremental Dynamic Analyses (IDAs) are performed for five generic frames of short-to-relatively long periods, under 40 pulse-like earthquake records. Statistical evaluation of the IDA results reveals that the optimal combination of spectral displacements, compared to that of spectral velocities, leads to less variability for all ranges of the frames. It is concluded that the optimal combination of spectral displacements can be used to predict seismic demands with dispersions less than those of Sa(T1), and which are closer to constant for various intensity levels. Additionally, with respect to the importance of collapse capacity predictions in earthquake engineering, an efficient IM that can considerably improve the accuracy of estimating the probability of collapse is also developed

Research paper thumbnail of Determination of Structural Fragility Curves of Various Building Types for Seismic Vulnerability Assessment in the Sarpol-e Zahab City

Journal of Seismology and Earthquake Engineering, Oct 1, 2018

Research paper thumbnail of Simulation of cyclic response of precast concrete beam-column joints

Computers and Concrete, Sep 1, 2019

Research paper thumbnail of Development of seismic fragility curves for precast concrete frames with cast-in-situ concrete shear-walls

Earthquake Engineering and Engineering Vibration, 2022

Precast reinforced concrete buildings have been well received in some seismic zones worldwide due... more Precast reinforced concrete buildings have been well received in some seismic zones worldwide due to advantages such as the ease and the speed of implementation, and the possibility of working in inappropriate atmospheric conditions. In this research, seismic fragility curves were developed for precast concrete frames with a cast-in-situ concrete shear-wall, concerning the important issues of modeling the precast beam-column joints, construction quality, and soil type effects. For this purpose, the incremental dynamic analysis (IDA) was conducted for three-dimensional models of 3-, 5-, and 8-story buildings under two record sets corresponding to soil types C and D of the NEHRP code. Beam-column joints were modeled using nonlinear rotational springs with rigid links with respect to the finite size of the joint panel. Results demonstrate that the Weibull distribution can be fitted to the damage state capacities better than the lognormal distribution at the intensities that are more th...

Research paper thumbnail of Introducing a New Scaling Method for Near-Fault Ground Motions Based on the Root-Mean-Square of Spectral Responses

Research paper thumbnail of Nonlinear Dynamic Analysis of Structures Under Near-Fault Ground Motions Using an Improved Scaling Method

Assessment of the seismic performance of a structure often requires conducting nonlinear dynamic ... more Assessment of the seismic performance of a structure often requires conducting nonlinear dynamic analyses under a set of ground motion records scaled to a specific level of intensity using an appropriate scaling method. In this study to reduce the variability in the seismic demands, a seismic-intensity scaling index is developed through studying weaknesses and strengths of different scaling methods. Results of the incremental nonlinear dynamic analyses of generic frames with 3, 6, 9, 12 and 15 storey under 40 near-fault ground motions show that using root-mean-square value of pseudo spectral accelerations over effective period range of structures can considerably reduce the scatter in the dynamic responses particularly once higher modes and period elongation effects dominate the response. By using this scaling method, the amount of dispersion is nearly independent of the ductility demand level and the number of stories.

Research paper thumbnail of ارائه مدل غیرخطی برای رفتار اتصالات خارجی تیر به ستون در ساختمانهای پیشساخته بتنی

Due to the increasing demand for housing, various communities are using the technology and advanc... more Due to the increasing demand for housing, various communities are using the technology and advanced equipment to build housing. Precast RC frame system is one of the methods used for this purpose. The most important features of this structural system are the high quality of construction due to the manufacturing of parts in the factory, the ease and speed of implementation, thus reducing the time gap between investment and utilization, also the possibility of working in poor atmospheric conditions. One of the important points in the implementation of precast concrete structures is how to connect the precast elements of the beam to the column, which will have a significant effect on the seismic behavior of these structures. In this paper, we have tried to estimate the seismic behavior of these structures using the behavior of some experiment specimens of precast joints, which are close to the executable details in Iran. To do this, a numerical model has been presented to consider the ...

Research paper thumbnail of Assessment of Structure-Specific Intensity Measures for the Probabilistic Seismic Demand Analysis of Steel Moment Frames

Arabian Journal for Science and Engineering

Research paper thumbnail of Bayesian probabilistic seismic hazard analysis with respect to near-fault effects

Asian Journal of Civil Engineering

Research paper thumbnail of Probabilistic seismic demand analysis of steel moment frames by utilising Bayesian statistics

European Journal of Environmental and Civil Engineering

Research paper thumbnail of Nonlinear Dynamic Analysis of Structures Under Near-Fault Ground Motions Using an Improved Scaling Method

Asian Journal of Civil Engineering

Assessment of the seismic performance of a structure often requires conducting nonlinear dynamic ... more Assessment of the seismic performance of a structure often requires conducting nonlinear dynamic analyses under a set of ground motion records scaled to a specific level of intensity using an appropriate scaling method. In this study to reduce the variability in the seismic demands, a seismic-intensity scaling index is developed through studying weaknesses and strengths of different scaling methods. Results of the incremental nonlinear dynamic analyses of generic frames with 3, 6, 9, 12 and 15 storey under 40 near-fault ground motions show that using root-mean-square value of pseudo spectral accelerations over effective period range of structures can considerably reduce the scatter in the dynamic responses particularly once higher modes and period elongation effects dominate the response. By using this scaling method, the amount of dispersion is nearly independent of the ductility demand level and the number of stories.

Research paper thumbnail of Studying Rooftop Damper Frame in Braced Structures under near and far field Earthquake Excitations

Rooftop tuned mass damper frame; linear dynamic analysis; nonlinear dynamic analysis; near field ... more Rooftop tuned mass damper frame; linear dynamic analysis; nonlinear dynamic analysis; near field earthquakes; far field earthquakes

Research paper thumbnail of Development of an Improved Intensity Measure in Order to Reduce the Variability in Seismic Demands Under Near-Fault Ground Motions

Journal of Earthquake and Tsunami, 2012

Intensity measure (IM) which describes the strength of an earthquake record plays an important ro... more Intensity measure (IM) which describes the strength of an earthquake record plays an important role in the seismic performance assessment of structures. An improved IM that can reduce the variability in seismic demands helps reducing the number of records necessary to predict the seismic performance with sufficient accuracy. In this study, an improved RMS-based IM is developed based on the results obtained from incremental dynamic analyses of short-to relatively long-period frames under an ensemble of near-fault pulse-like earthquake records. It is observed that the root-mean-square value of pseudo spectral accelerations, (Sa) rms , is generally superior to that of spectral velocities, (Sv) rms , in seismic demand prediction under near-fault records. To compute (Sa) rms as IM, two appropriate period ranges are suggested for short- and moderated-to relatively long-period frames, respectively. Comparing the efficiency of (Sa) rms with several advanced IMs shows that (Sa) rms is more e...

Research paper thumbnail of New scalar intensity measure for near-fault ground motions based on the optimal combination of spectral responses

Scientia Iranica, 2011

ABSTRACT Intensity Measure (IM), characterizing the strength of an earthquake ground motion, is u... more ABSTRACT Intensity Measure (IM), characterizing the strength of an earthquake ground motion, is used to predict the seismic responses of a structure. Recent studies have demonstrated that using Sa(T1) as the seismic scaling index for near-fault ground motions may introduce large variability in the estimated seismic demands. To develop an improved IM, this paper investigates the effectiveness of a large number of combinations of spectral values in reducing scatter in the estimated maximum interstorey drift ratios. For this purpose, Incremental Dynamic Analyses (IDAs) are performed for five generic frames of short-to-relatively long periods, under 40 pulse-like earthquake records. Statistical evaluation of the IDA results reveals that the optimal combination of spectral displacements, compared to that of spectral velocities, leads to less variability for all ranges of the frames. It is concluded that the optimal combination of spectral displacements can be used to predict seismic demands with dispersions less than those of Sa(T1), and which are closer to constant for various intensity levels. Additionally, with respect to the importance of collapse capacity predictions in earthquake engineering, an efficient IM that can considerably improve the accuracy of estimating the probability of collapse is also developed