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Several bridges in Indonesia are designed using elastomeric bearing (ERB) with a low capability of reducing seismic responses. This results in a significant demand for larger pier crosssectional dimensions and a greater number of reinforcements, necessitating the consideration of seismic isolation devices to optimize the pier configuration. Lead rubber bearing (LRB) has been widely used as a seismic isolation device due to the natural period shifting and sufficient energy dissipation, but it costs a lot. A shear panel damper equipped with a gap (SPDG) was proposed regarding its capability to provide high damping at low cost as an alternative device to LRB. This study compared the seismic performance of three structural systems of simply supported prestressed concrete (PSC) box girder bridges. Those were analyzed using Nonlinear Time History Analysis (NLTHA) with the OpenSees software. As a result, both SPDG and LRB increased the structural flexibility and generated similar relative pier responses to the conventional bridge with ERB. For example, SPDG generated the relative responses of the top pier displacement, base shear, and bending moment up to 64.76%, 83.55%, and 65.66%, while LRB was 64.92%, 83.39%, and 66.89%, respectively. Meanwhile, the bridge's structural performance equipped with LRB and SPDG showed a fully operational and operational limit, while the one with ERB reached the life safety limit due to the longitudinal earthquake. The life safety limit due to the transverse earthquake was also observed in the three bridge models. In conclusion, SPDG is applicable in the seismic isolation system as it has a similar performance to the LRB. [ABSTRACT FROM AUTHOR]

In this paper, a physical index for quantitatively evaluating the non-proportional damping characteristics is proposed. Additionally, a direct design approach applicable to composite isolated structures (consisting of an upper damping structure and a base isolation system) is proposed for performance analysis of practical three-dimensional non-proportional damped structures. Furthermore, the elastic–plastic behavior of the structure under acceleration excitation is considered to determine the structural damage and response, improving computational accuracy and providing better solutions for the analysis and design of composite isolated structures. Analysis studies have shown that under rare and extremely rare earthquake events, structures designed using the complex modal response spectrum method (CM-RSM) exhibit less damage compared to those designed using the forced decoupling response spectrum method (FD-RSM) compared to the results obtained using the complex modal response spectrum method. For the seismic performance study of non-proportional damped structures, it is recommended to use the complex modal response spectrum method. With an increasing earthquake intensity, the proportion of energy dissipation due to the nonlinear strain energy dissipation of a structure increases, and the proportion of energy dissipation due to the isolators and dampers in the damping energy portion decreases. [ABSTRACT FROM AUTHOR]

The probabilistic seismic demand model (PSDM) is essential to identify the seismic demand of the highway bridge during and after an earthquake. This paper aims to review the probabilistic seismic demand estimation and modeling methodology options associated with the procedure, analytical analysis, and mathematical framework for a highway bridge. As a result of the review, different techniques with features, applications, and limitations on highway bridges are reviewed and presented. A review has investigated the current PSDM and provides a comprehensive summary with formulas, tables, figures, and frameworks. PSDM steps are constructed and introduced to how scholars use them. Besides, analytical methods are the best choice for investigating the PSDA and PSDM for critical bridge components when damage data is insufficient. They are determined to predict each component's seismic response for a given deterministic or random variable. This work helps and motivates the decision-makers and stakeholders to extend the application of the PSDM methodology option for a more informed decision. [ABSTRACT FROM AUTHOR]

In the general practice of performance-based seismic assessment and dynamic analysis of building structures, the recorded ground motions from past earthquake events are selected and modified according to the site conditions and hazard level of the project's site. For this purpose, only the mainshock earthquake event is considered for the analysis while neglecting the foreshocks and aftershocks. However, in several real cases, especially for existing RC buildings with non-seismic detailing, low- to moderate-magnitude foreshocks and aftershocks may also affect the seismic performance. Several studies have shown that the application of repeated earthquake events may lead to damage accumulation and significant seismic losses, even if the structure is at a life safety performance level. This study examines the seismic performance of mid-rise RC frame structures in Pakistan under repeated earthquakes. For this purpose, a representative case study building has been selected for the detailed analysis after surveying typical existing RC buildings in Pakistan. The detailed nonlinear finite element model is constructed and subjected to several cases of repeated earthquakes with different intensity levels. The seismic performance in terms of key demand parameters is evaluated for single earthquake scenarios (mainshock only) and seismic sequences (foreshock, mainshock, and aftershock). The results showed the application of seismic sequences has a negligible effect on the peak seismic force and displacement demands of the buildings compared to the single mainshock event. However, an increase in seismic performance indicators, including residual displacements and inelastic hysteretic energy, is observed. Resultantly, an increase in structural damage (quantified in terms of material cracking, yielding, crushing, etc.) is also observed for ground motion sequences compared to the single ground motion. [ABSTRACT FROM AUTHOR]

Investigating the impact of near-field ground motions on the fragility curves of multi-span simply supported concrete girder bridges is the main goal of this paper. Fragility curves are valuable tools for evaluating seismic risks and vulnerabilities of bridges. Numerous studies have investigated the impact of ground motions on the fragility curves of bridges. Ground motions are commonly categorized into two sets, based on the distance of the recorded station from the seismic source: far-field and near-field. Studies examining the influence of near-field records on bridge fragility curves vary depending on the specific bridge type and type of fragility curve being analyzed. Due to the widespread use of multi-span simply supported concrete girder bridges in the Central and Southeastern United States, this study makes use of this bridge type. This research investigates the component fragility curves for column curvatures, bearing deformations, and abutment displacements by employing 3-D analytical models and conducting nonlinear time history analysis. These curves illustrate the impact of near-field ground motions on different components. The component fragility curves for two sets of records, 91 near-field ground motions and 78 far-field ground motions, were obtained and compared. These findings demonstrate that near-field ground motions have a greater damaging effect on columns and abutments than far-field earthquakes. When it comes to bearing deformations, the far-field earthquake impact is more severe at lower intensities, whereas the impact of the near-field ground motion is stronger at higher intensities. [ABSTRACT FROM AUTHOR]

Seismic analysis of historical masonry bridges is important for authorities in all countries hosting such cultural heritage assets. The masonry arch bridge investigated in this study was built during the Roman period and is on the island of Rhodes, in Greece. Fifteen seismic records were considered and categorized as far-field, pulse-like near-field, and non-pulse-like near-field. The earthquake excitations were scaled to a target spectrum, and nonlinear time-history analyses were performed in the transverse direction. The performance levels were introduced based on the pushover curve, and the post-earthquake damage state of the bridge was examined. According to the results, pulse-like near-field events are more damaging than non-pulse-like near-field ground motions. Additionally the bridge is more vulnerable to far-field excitations than near-field events. Furthermore, the structure will suffer extensive post-earthquake damage and must be retrofitted. [ABSTRACT FROM AUTHOR]

Today, population growth and the need for constructing adjacent buildings have raised the likelihood of pounding between adjacent buildings with different dynamic characteristics. The pounding force applied to adjacent buildings during an earthquake is intensive and may cause total or partial damage to structural elements, leading to collapse. It disturbs and complicates the functioning of buildings during and after an earthquake. Therefore, the main aim of this paper is to minimize and, if possible, eliminate the pounding force between two adjacent structures by considering three objective functions. For this aim, the tuned mass damper is utilized here. Also, this paper aims to reduce the number of collisions between different stories of adjacent buildings through a tuned mass damper system. For this purpose, two adjacent steel moment frames with six and ten stories are nonlinearly modeled and validated using the concentrated plasticity model in OpenSees. Moreover, the pounding element is nonlinearly modeled and validated. Then, tuned mass dampers (TMDs) are used on the roofs of the structures. They are optimized in stiffness, mass, and damping coefficient using the grey wolf optimization (GWO) algorithm. Nonlinear time history analysis (NLTHA) is performed under nine far- and near-field earthquakes. The pounding force and structural responses are analyzed, including maximum story acceleration, maximum inter-story drift, and base shear in the TMD-controlled and uncontrolled adjacent buildings. Finally, the Park-Ang damage index is evaluated for the structures with and without the TMD system. It has been found that the maximum pounding force, the maximum acceleration of the stories, the base shear, the drift ratio, and the number of collisions significantly reduce (or omit) in the presence of TMDs when the objective function is considered to be the minimization of the maximum pounding force. It is shown that the maximum pounding force generally declines to zero for this objective function. • TMD attenuated the peak story acceleration in both buildings' stories under all the earthquake records. • The optimized TMD system reduced the peak inter-story drift. • The TMD diminished the base shear in both buildings under some records. Under some other earthquake records, however, the TMD system increased the base shear in one of the two buildings and reduced that in the other one. • Overall, the peak pounding force significantly declined in the top two stories in the presence of the TMD system. • Hence, it can be said that an optimized TMD system would be an efficient and effective approach for pounding force and collision reduction within adjacent buildings in the event of pounding. [ABSTRACT FROM AUTHOR]

Shape memory alloys (SMA) can regain their original shape upon unloading, making them an excellent option for self-centering dampers due to their unique mechanical features, such as super elasticity and shape memory effect. Furthermore, SMA wire dampers exhibit consistent energy dissipation properties, allowing them to distribute a precise amount of energy effectively during seismic events. This paper presents a novel configuration of an SMA wire damper that is easy to install in the structure. In this research, we assess the effectiveness of SMA wire dampers in mitigating seismic responses of asymmetric single-story frames subjected to a range of far-field and near-field earthquake ground motions. The investigation explores the lateral and angular displacements, acceleration, base shear, and stiff and flexible edge displacements concerning eccentricity ratio, lateral period, and uncoupled torsional to lateral frequency ratio. We use Taguchi's design of experiments (DOE) to analyse how different parameters impact the performance of SMA dampers in the structure. The results showed a significant enhancement in the seismic resilience of the structures with the implementation of SMAs wire dampers. These dampers effectively reduced the peak structural reaction by 13 %. Despite changes in eccentricity and frequency ratios, the root mean square (RMS) response ratio of the controlled and uncontrolled structure with the SMA damper is constantly below one, proving its efficacy. • These optimised combinations can help design the control device and structure. • Taguchi method for DOE and finding the most efficient SMA wire damper structural parameter. • SMA dampers reduce earthquake RMS response by 25%. • The equation was proposed for the complicated structural response-influence input variable relationship. • The RMS response ratio of the controlled and uncontrolled structure with the SMA damper remains below one. [ABSTRACT FROM AUTHOR]

The studies on the seismic control of a secondary system (S-system) in the base-isolated primary system under multicomponent earthquake is scanty. In this study, an S-system response mounted on a floor of a three-dimensional (3D) base-isolated building is investigated under three component earthquake. The main objective of the study is to examine the response reductions of the S-system in all three directions, including the vertical direction, in which the building is not isolated. For the purpose of the study, two 6-story 3D building models, one base isolated and the other nonisolated, are analyzed. The S-system consists of a single portal frame with a mass at its center. The nonlinear time history analysis of both building models is carried out for three component ground motion, using commercial software SAP 2000, in order to study the control of response of the S-system. The nature, peak ground acceleration (PGA), and component ratios of the earthquake are varied to perform the parametric study. The findings of the study show that significant reduction in the lateral displacement and acceleration of the S-system is achieved by base isolating the building. In addition, the S-system's vertical responses are reduced despite the isolation being ineffective in the vertical direction. [ABSTRACT FROM AUTHOR]

In this research, the seismic behavior of single-layer diamatic dome (SLDD) structures was analyzed under earthquake loads, and then the seismic response modification factors (SRMFs) of these structures were extracted. For this purpose, 16 models with different span lengths (SLs) and rise-to-span ratios (RSRs) were designed, and the effects of SL and RSR on the SRMFs of these structures were evaluated. Also, the effect of member density on the SRMFs was studied. The models were first designed under the applied loads based on relevant design codes. Then, by performing the nonlinear time history analyses using the three translational components of ground motion records, the control point and target displacement in the horizontal and vertical directions were obtained to implement the pushover analyses. Thereafter, the pushover analyses were implemented by using the target displacements derived from the nonlinear time history analyses, and the SRMFs of SLDD structures in both horizontal and vertical directions were obtained. The results indicate that models with RSRs of 1/7 to 1/3 remained in the elastic range in the horizontal direction. For the models with an RSR greater than 1/3, if the RSR increases, the ductility and behavior factor increases in the horizontal direction. However, there is a downward trend in the vertical direction due to the increase in the vertical stiffness. The horizontal and vertical behavior factor was obtained in the range of 1.155–2.459 and 1.155–2.893, respectively. Finally, by using the results obtained and through the nonlinear regression analysis, equations were proposed for the period, target displacement, displacement amplification factor, and behavior factor for SLDD structures in terms of the SL and RSR in the horizontal and vertical directions. • The seismic response modification factors (SRMFs) of single-layer diamatic dome structures are extracted. • The effect of member density on the SRMFs is studied. • Equations were proposed for the period, target displacement, behavior factor, and displacement amplification factor. • The SRMFs of these structures are obtained in both horizontal and vertical directions. [ABSTRACT FROM AUTHOR]

Summary: The use of energy dissipaters for creation of earthquake‐resilient buildings has been paid more and more attention in recent years, and some newly developed structural fuses or dampers have been proposed to be employed in rocking and seesaw buildings. In this study, a new type of yielding‐based dampers, called curved‐yielding‐plates energy dissipater (CYPED), is introduced. CYPEDs are installed at the bottom of rocking or seesaw building's circumferential columns at the lowest story and have hysteretic behavior in their deformation occurring in vertical direction. The initial curvature of the yielding plates prevents them from buckling and gives the device a smooth force–deformation behavior. First, by performing a set of cyclic tests on three specimens of CYPED, their hysteretic force–displacement behavior was investigated. Then, to show the efficiency of this energy dissipating device in reducing the seismic response of buildings, they were employed numerically as multilinear plastic springs in the computer models of a sample seesaw steel building, and a series of nonlinear time history analysis (NLTHA) were performed on both seesaw building and its conventional counterpart. Results of NLTHA show that the proposed seesaw structural system equipped with appropriate CYPEDs not only gives the building a longer natural period, leading to lower seismic demand, but also leads to remarkable energy dissipation capacity in the building structure at base level and, therefore, keeping the seismic drifts in elastic range in all stories of the building. In this way, the building structure does not need any major repair work, even after a large earthquake, while the conventional building suffers from heavy damage and is not usable after the earthquake. [ABSTRACT FROM AUTHOR]

Nepal Himalayas is one of the most seismic vulnerable zones. The active tectonic action impels the assessment of structures in possible seismic hazards including the bridge structures. This paper presents the impact of the 2015 Gorkha earthquake on the existing reinforced concrete arch bridge at Chobhar, Nepal. A three-dimensional model of the bridge is constructed using OpenSees platform. Nonlinear pushover analysis was performed to find the displacement capacity of the bridge. Ground motion from the main shock of the 2015 Gorkha earthquake is used in this study. Nonlinear time history analysis is performed with three orthogonal ground motions applied in the transverse, longitudinal and vertical direction of the bridge. The study investigates the safety of the bridge scaling up the ground motion to potential PGA in Nepal Himalayas; the result demonstrated the necessity of retrofit to ensure the safety level. Moreover, the horizontal seismic force obtained from the time history analysis is compared with the force obtained from the design code of the bridge. Also, the design force as per the present code (revised code) is presented. [ABSTRACT FROM AUTHOR]

Summary: Drift is a dominant feature in tall‐building design and can dictate the selection of structural systems. Because a reliable estimate of actual drifts is crucial for controlling structural damage, estimating drift considering intricate details seems noteworthy. In order to estimate story drifts during massive quakes, seismic design provisions generally specify a deflection amplification factor (Cd) to amplify elastic design drifts. In most of these codes, the amount of Cd is calculated from line‐element models without considering panel zone effects, despite the panel zone intensifying the story drift considerably. Therefore, the effect of panel zone on the story drift and Cd has been investigated in the current paper. Because Cd is independent of the number of stories, 4‐story frames, as benchmarks for special steel moment frames, with different thicknesses of the panel zone, are used. The effect of panel zone is provided as a correction factor for Cd. The results show that the panel zone should be considered in the analytical models; otherwise, the story drift will be underestimated up to 35%. Finally, a relation has been derived to consider panel zone effects on Cd, as a function of the panel zone thickness. [ABSTRACT FROM AUTHOR]

Many devastating earthquakes exceeding the design basis levels have occurred in the past. Safety assessment of equipments and piping systems of industrial/nuclear safety related structures subjected to earthquakes beyond design basis levels necessitates consideration of the structural nonlinearity. The In-structure or floor response spectra (FRS) are the input required for qualification of these systems and hence it is essential to generate this input considering structural nonlinearity. This paper addresses the experimental and analytical work on generation of FRS for nonlinear Reinforced Cement Concrete (RCC) structure. Push over and shake table experiments are performed on three storeyed RCC framed structure. A simplified analytical approach is proposed to derive earthquake-induced In-structure response spectra for the structure deforming beyond elastic limits. In this approach, initially, the performance of the structure is evaluated using pushover analysis. Floor spectra of the structure are then obtained considering the degraded stiffness and increased damping evaluated at each performance level iteratively from pushover curve. The floor spectra of the structure generated by the proposed method are validated using experimentally simulated results from shake table tests. [ABSTRACT FROM AUTHOR]

Simulated ground motions can be used in structural and earthquake engineering practice as an alternative to or to augment the real ground motion data sets. Common engineering applications of simulated motions are linear and nonlinear time history analyses of building structures, where full acceleration records are necessary. Before using simulated ground motions in such applications, it is important to assess those in terms of their frequency and amplitude content as well as their match with the corresponding real records. In this study, a framework is outlined for assessment of simulated ground motions in terms of their use in structural engineering. Misfit criteria are determined for both ground motion parameters and structural response by comparing the simulated values against the corresponding real values. For this purpose, as a case study, the 12 November 1999 Duzce earthquake is simulated using stochastic finite-fault methodology. Simulated records are employed for time history analyses of frame models of typical residential buildings. Next, the relationships between ground motion misfits and structural response misfits are studied. Results show that the seismological misfits around the fundamental period of selected buildings determine the accuracy of the simulated responses in terms of their agreement with the observed responses. [ABSTRACT FROM AUTHOR]

An energy-based approach for determining earthquake safety of reinforced concrete frame structures is presented. The developed approach is based on comparison of plastic energy capacities of the structures with plastic energy demands obtained for selected earthquake records. Plastic energy capacities of the selected reinforced concrete frames are determined graphically by analyzing plastic hinge regions with the developed equations. Seven earthquake records are chosen to perform the nonlinear time history analyses. Earthquake plastic energy demands are determined from nonlinear time history analyses and hysteretic behavior of earthquakes is converted to monotonic behavior by using nonlinear moment-rotation relations of plastic hinges and plastic axial deformations in columns. Earthquake safety of selected reinforced concrete frames is assessed by using plastic energy capacity graphs and earthquake plastic energy demands. The plastic energy dissipation capacities of the frame structures are examined whether these capacities can withstand the plastic energy demands for selected earthquakes or not. The displacements correspond to the mean plastic energy demands are obtained quite close to the displacements determined by using the procedures given in different seismic design codes. [ABSTRACT FROM AUTHOR]

In this study, seismic assessment of one story precast industrial buildings that constitute majority of industrial facilities in Turkey was investigated by using probabilistic approach. For this purpose, 98 one story precast industrial buildings that represent general structural aspects of precast industrial building stock of Turkey were used. Strength and deformation capacities of buildings were determined by inelastic methods and seismic demands were calculated by nonlinear time history analyses. In order to represent low, moderate and high intensity earthquake levels, more than 300 ground motion records were used. Fragility curves of precast buildings were then constructed by comparing the displacement capacities and seismic demands. Peak ground velocity was used as ground motion parameter to construct analytical fragility curves. Assessment of inventory buildings was performed by considering the effect of lateral strength ratio, stiffness and ductility parameters. Observations have shown that probabilities of lower damage levels (slight and moderate) are almost similar and they are independent from structural parameters considered. It was also observed that ductility and lateral strength ratios (V/W) have significant effect on seismic fragilities of precast industrial buildings at higher damage levels. Based on the observations, building stock was classified in three groups. Results have shown that strength and ductility based classification of existing precast industrial buildings is quite effective and it can be used as an important tool for the seismic assessment studies of one story precast industrial buildings. [ABSTRACT FROM AUTHOR]

The paper investigates the structural performance of a seven-story reinforced concrete (RC) building that collapsed during the Van (Turkey) earthquake on October 23, 2011, using nonlinear static and dynamic methods. The selected RC building has two blocks and was designed according to the Turkish Earthquake Code (TEC) in 1975. The site investigation included sections and steel detailing and soil and concrete properties taken after the earthquake. The pushover and nonlinear time history analyses of the building were completed using the existing plan and test and observation data. It is concluded that the building collapses both analysis types. [ABSTRACT FROM AUTHOR]

This paper investigated the structural feasibility of braced-damper system with adaptive negative stiffness devices (i.e., negative stiffness amplifying damper, NSAD) in yielding multi-storey steel frames (MSFs). The nonlinear analytical model of yielding MSFs with NSADs was established. Seismic responses of a 3-storey typical structure with and without NSAD were evaluated to illustrate the working mechanism of NSAD applied at yielding MSFs. Parametric study concerning the maximum inter-storey drift, residual deformation, and structural acceleration was conducted thoroughly to quantify the effect of NSAD. The rational distribution of NSADs was also discussed respectively for both regular and irregular yielding MSFs. Numerical results showed that the adaptive NSAD is effective in mitigating inter-storey drift, residual deformation, and structural acceleration of yielding MSFs when subjected to multiple intensities of earthquakes. It is recommended that the adaptive NSAD shall be applied at storeys with small drift response, i.e., whose stiffness (previous conclusion on elastic MSFs) and strength (new contribution of this paper on yielding MSFs) are high. In other word, the feature of NSAD that helps reducing non-arranged storey drift is also valid for the plastic scenarios. • Establishing nonlinear model of yielding MSF with nonlinear adaptive NSADs; • Nonlinear responses quantification concerning drift, residual deformation, and acceleration; • Absolute negative stiffness ratio and displacement ratio are suggested to be lower than 0.3 and 1.2. • Highlighting the importance of MSF strength in influencing the drift of storeies without NSAD. [ABSTRACT FROM AUTHOR]

In this study, dynamic responses of the multistory base-isolated and base-fixed buildings are investigated under near- and far-fault ground motions. Lead-rubber isolation bearing (LRB) is used in the examination. First, the mechanical properties for LRB isolation system are calculated. The seismic analysis of the buildings is executed by nonlinear time history analysis method for reinforced-concrete two-dimensional building frames. For the purpose of analysis, three records of far-field and three records of near-fault ground motions from the same components are selected in different stations and conducted on building frames. The results of the analysis for isolated-base and fixed-base frames are compared with each other under far- and near-fault ground motions. Story drift, acceleration of the each story, base shear and base displacement are examined as results of the analysis. These results show that the isolators absorb the seismic energy well enough such that there is a considerable reduction in the majority of the dynamic responses. Reduction in the floor acceleration of the middle floors is observed more than in the base and top floor. Base displacement is more considerable in isolated buildings subjected to near-fault than far-fault ground motions. [ABSTRACT FROM AUTHOR]

In order to study the effect of damage caused by local buckling on the seismic behavior of steel frames under severe earthquakes, beam element model and fine shell element model were respectively established by ABAQUS. The differences caused by damage of two models were compared. Shell element model was proved correct and applicable comparing with typical quasi-static tests, which was considered to accurately describe the degraded behavior. Base on this confirmation, beam element model and shell element model were performed for quasi-static and nonlinear time history analysis. The characteristics of structural deformation, hysteresis energy and failure modes were compared. The results show that: before the occurrence of damage and degradation, seismic indices calculated by the two models are in accordance. However, once local buckling causes damage, the results of the two models are remarkably different. Beam element model underestimated the structural deformation and plasticity development level. [ABSTRACT FROM AUTHOR]

SUMMARY The design of a three-story buckling-restrained braced frame (BRBF) with a single-diagonal sandwiched BRB and corner gusset was evaluated in cyclic tests of a one-story, one-bay BRBF subassembly and dynamic analyses of the frame subjected to earthquakes. The test focused on evaluating (1) the seismic performance of a sandwiched BRB installed in a frame, (2) the effects of free-edge stiffeners and dual gusset configurations on the corner gusset behavior, (3) the frame and brace action forces in the corner gusset, and (4) the failure mode of the BRBF under the maximum considerable earthquake level. The subassembly frame performed well up to a drift of 2.5% with a maximum axial strain of 1.7% in the BRB. Without free-edge stiffeners, the single corner gusset plate buckled at a significantly lower strength than that predicted by the specificationof American Institute of Steel Construction (2005). The buckling could be eliminated by using dual corner gusset plates similar in size to the single gusset plate. At low drifts, the frame action force on the corner gusset was of the same magnitude as the brace force. At high drifts, however, the frame action force significantly increased and caused weld fractures at column-to-gusset edges. Nonlinear time history analyses were performed on the three-story BRBF to obtain seismic demands under both design and maximum considerable levels of earthquake loading. The analytical results confirmed that the BRB and corner gusset plate achieved peak drift under cyclic loading test. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper presents the seismic evaluation of high-strength steel first-story columns in a seven-story dual system, composed of a special moment-resisting frame (SMRF) and buckling-restrained braced frame (BRBF), in near-fault and post near-fault earthquakes. Nonlinear time history analyses were conducted on the frame to develop loading protocols that represent seismic demands on the first-story columns in the dual system. The proposed near-fault displacement protocol has a large displacement pulse from -2 to +4% drift, followed by small displacement cycles oscillated at a residual drift of 2.5%. The proposed far-field displacement protocol is an increasingly cyclic displacement protocol with one cycle after a drift of 2%. Two built-up H-shaped column specimens (HC-20-B and HC-20-C) and two built-up box column specimens (HBC-40-B and HBC-40-C), representing the first-story columns in the dual system, are tested under constant axial force (0.2 P y or 0.4 P y) and lateral drifts based on the proposed loading protocols. These specimens that satisfy the compactness requirement of highly ductile members in AISC 341-16 (2016) show acceptable seismic performance under the near-fault earthquake loading. However, the flexural strength of HC specimens decreases with increasing drift, and that of HBC specimens increases without strength degradation. The HBC specimens can perform well in the subsequent near-fault or far-fielding earthquake loading, which is not the case for the HC specimens due to significant local buckling. The NIST (2017) backbone curve reasonably predicts the test envelope of the HC specimens, but significantly underestimates the test envelope of the HBC specimens. • High-strength steel columns were tested under near-fault and subsequent loadings. • A near-fault loading protocol was developed based on a BRBF in ground motions. • Deep H-shaped columns and box columns were under axial force and lateral drifts. • Backbone curves based on codes are compared with test envelope of specimens. [ABSTRACT FROM AUTHOR]