• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.3
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• pp.169-181
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• 2019

Seismic performance of ordinary reinforced concrete shear wall systems commonly used in high-rise residential buildings is evaluated. Three types of shear walls exceeding 60m in height are designed by performance-based seismic design. Then, incremental dynamic analysis is performed collapse probability is assessed in accordance with the procedure of FEMA P695. As a result, story drift, plastic rotation, and compressive strain are observed to be major failure modes, but shear failure occur little. Collapse probability and collapse margin ratio of performance groups do not meet requirement of FEMA P695. It is observed that critical wall elements fail due to excessive compressive strain. Therefore, the compressive strain of concrete at the boundary area of the shear wall needs to be evaluated with more conservative acceptance criteria.

• Structural Engineering and Mechanics
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• v.57 no.4
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• pp.641-656
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• 2016

Reinforced concrete frame buildings with masonry infill walls are one of the most popular structural systems in the world. In most cases, the effects of masonry infill walls are not considered in structural models. The results of earthquakes show that infill walls have a significant effect on the seismic response of buildings. In some cases, the buildings collapsed as a result of the formation of a soft story. This study developed a simple method, called corner opening, by replacing the corner of infill walls with a very flexible material to enhance the structural behavior of walls. To evaluate the proposed method a series of experiments were conducted on masonry infill wall and reinforced concrete frames with and without corner openings. Two 1:4 scale masonry infill walls with and without corner openings were tested under diagonal tension or shear strength and two RC frames with full infill walls and with corner opening infill walls were tested under monotonic horizontal loading up to a drift level of 2.5%. The experimental results revealed that the proposed method reduced the strength of infill wall specimens but considerably enhanced the ductility of infill wall specimens in the diagonal tension test. Moreover, the corner opening in infill walls prevented the slid shear failure of the infill wall in RC frames with infill walls.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.2
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• pp.91-99
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• 2023

Structural vibration induced by earthquake hazards is one of the most significant concerns in structure performance-based design. Structural hazards evoked from seismic events must be properly identified to make buildings resilient enough to withstand extreme earthquake loadings. To investigate the effects of combined earthquake-resistant systems, shear walls and five types of dampers are incorporated in nineteen structural models by altering their arrangements. All the building models were developed as per ACI 318-14 and ASCE 7-16. Seismic fragility curves were developed from the incremental dynamic analyses (IDA) performed by using seven sets of ground motions, and eventually, by following FEMA P695 provisions, the collapse margin ratio (CMR) was computed from the collapse curves. It is evident from the results that the seismic performance of the proposed combined shear wall-damper system is significantly better than the models equipped with shear walls only. The scrutinized dual seismic resisting system is expected to be applied practically to ensure a multi-level shield for tall structures in high seismic risk zones.

• Architectural research
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• v.24 no.3
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• pp.75-84
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• 2022

Scads of earthquake-resistant systems are being invented around the globe to ensure structural resistance against the lateral forces induced by earthquake loadings considering structural safety, efficiency, and economic aspects. Shear wall and Bracing systems are proved to be two of the most viable solutions for seismic strengthening of structures. In the present study, three numerical models of a G+10 storied building are developed in commercial building analysis software considering shear wall and bracing systems for earthquake resistance. Material nonlinearity is introduced by using plastic hinges. Analyses are performed utilizing two dynamic methods: Response Spectrum analysis and nonlinear Time-history analysis using Kobe and Loma Prieta earthquake data and results are compared to observe the nonlinear behavior of structures. The outcomes exposed that a significant increase in the seismic responses occurs due to the nonlinearity in the building systems. It was also found that building with shear wall exhibits maximum resistance and minimum nonlinearity when subjected to dynamic loadings.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.185-190
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• 2001

The severe shortage of the available sites in the highly developed downtown area in Korea necessitates the construction of high-rise buildings which meet the need of residence and commercial activity simultaneously. The objective of this study is to investigate the seismic performance of this type of building structures. For this purpose, two 1:12 scale 17-story reinforced concrete model structures were constructed according to the similitude law, in which the upper 15 stories have a bearing-wall system while the lower 2-story frames with infilled shear wall have two different layouts of the plan : The one has symmetric plan and the other has unsymmetric plan. Then, this model was subjected to a series of earthquake excitations. The test results show that the layout of shear wall has the negligible effect on the natural period and the base shear coefficient, but great effect on the failure mode of beam-column joint at flexible side frame.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.865-872
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• 2006

Recently, many apartment buildings in the shear wall system often has pilotis in the lower story to meet the architectural needs. If the lateral force resisting system consists of shear walls supported by columns and beams. the discontinuity at the lowest level with pilotis results in the vertical irregularity with strength and stiffness. So, there are needs to be considered tile analysis and design about column and beam bellow shear walls and the behavior and stress condition of structure by stiffness change being generated at shear walls. The purpose of this paper is to investigate the behavior of shear wall structures with pilotis using the floors modeled as rigid diaphragm or semi rigid diaphragm. Through analyses, after estimating values of the story drift, natural period, stress condition of shear walls and the forces of column, we inferred how the behavior of shear wall structures with pilotis was influenced by the floor stiffness.

• Computers and Concrete
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• v.31 no.4
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• pp.337-348
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• 2023

Shear wall is commonly used as a lateral force resisting system of concrete mid-rise and high-rise buildings, but it brings challenges in providing relatively large space throughout the building height. For this reason, the structure system where the upper structure with bearing, non-bearing and/or shear walls that sits on top of a transfer plate system supported by widely spaced columns at the lower stories is preferred in some regions, particularly in low to moderate seismic regions in Asia. A thick reinforced concrete (RC) plate has often been used as a transfer system, along with RC transfer girders; however, the RC plate becomes very thick for tall buildings. Applying the post-tensioning (PT) technique to RC plates can effectively reduce the thickness and reinforcement as an economical design method. Currently, a simplified model is used for numerical modeling of PT transfer plate, which does not consider the interaction of the plate and the upper structure. To observe the actual behavior of PT transfer plate under seismic loads, it is necessary to model whole parts of the structure and tendons to precisely include the interaction and the secondary effect of PT tendons in the results. This research evaluated the seismic behavior of shear wall-type residential buildings with PT transfer plates for the condition that PT tendons are included or excluded in the modeling. Three-dimensional finite element models were developed, which includes prestressing tendon elements, and response spectrum analyses were carried out to evaluate seismic forces. Two buildings with flat-shape and L-shape plans were considered, and design forces of shear walls and transfer columns for a system with and without PT tendons were compared. The results showed that, in some cases, excluding PT tendons from the model leads to an unrealistic estimation of the demands for shear walls sit on transfer plate and transfer columns due to excluding the secondary effect of PT tendons. Based on the results, generally, the secondary effect reduces shear force demand and axial-flexural demands of transfer columns but increases the shear force demand of shear walls. The results of this study suggested that, in addition to the effect of PT on the resistance of transfer plate, it is necessary to include PT tendons in the modeling to consider its effect on force demand.

• Earthquakes and Structures
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• v.7 no.1
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• pp.101-117
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• 2014

This paper presents a reliability-based analysis on seismic performance of timber-steel hybrid shear wall systems. Such system is composed of steel moment resisting frame and infill wood frame shear wall. The performance criteria of the hybrid system with respect to different seismic hazard levels were determined through a damage assessment process, and the effectiveness of the infill wood shear walls on improving the seismic performance of the hybrid systems was evaluated. Performance curves were obtained by considering different target non-exceedance probabilities, and design charts were further established as a function of seismic weight. Wall drift responses and shear forces in wood-steel bolted connections were used as performance criteria in establishing the performance curves to illustrate the proposed design procedure. It was found that the presence of the infill wood shear walls significantly reduced the non-performance probabilities of the hybrid wall systems. This study provides performance-based seismic evaluations on the timber-steel hybrid shear walls in support of future applications of such hybrid systems in multi-story buildings.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5199-5205
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• 2013

Despite the increasing incidence of earthquakes in recent years, many of the existing buildings don't have appropriate seismic performance due to the deterioration or structural characteristics. In particular, a piloti-type RC shear wall structure, which is one of the building types in Korea, is highly vulnerable to earthquakes due to a great lack of shear function that can resist lateral force caused by the earthquake since the first floor is mostly soft story, and it is classified as weak story. In this regard, a study on the damage state criterion for the piloti-type RC shear wall structures was carried out. The capacity spectrum was calculated through the structural analysis by selecting typical type of buildings of shear wall systems, and damage state criterion was defined based on the shape of the capacity spectrum.

• Structural Engineering and Mechanics
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• v.71 no.5
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• pp.563-576
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• 2019

According to The Concrete Centre, in the UK shear walls have become an inseparable part of almost every reinforced concrete frame building. Recently, the construction industry has questioned the need for shear walls in low to mid-rise RC frame buildings. This study tried to address the issue in two stages: The first stage, the feasibility of removing shear walls in an existing design for a residential building where ETABS and CONCEPT software were used to investigate the structural performance and cost-effectiveness respectively. The second stage, the same structure was examined in various locations in the UK to investigate regional effects. This study demonstrated that the building without shear wall could provide adequate serviceability and strength within the safe range defined by Eurocodes. As a result, construction time, overall cost and required concrete volume are reduced which in turn enhance the sustainability of concrete construction.