• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.4
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• pp.211-222
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• 2016

Reinforced concrete shear walls with deficient reinforcement details are tested under cyclic loading. The deficiency of reinforcement details includes insufficient splice length in U-stirrups at the ends of horizontal reinforcement and boundary column dowel bars found in existing low- to mid-rise Korean buildings designed non-seismically. Three test specimens have rectangular, babel and flanged sections, respectively. Flexure- and shear-controlled models for reinforced concrete shear walls specified in ASCE/SEI 41-13 are compared with the flexural and shear components of force-displacement relation extracted separately from the top displacement of the specimen based on the displacement data measured at diverse locations. Modification of the shear wall models in ASCE/SEI 41-13 is proposed in order to account for the effect of bar slip, cracking loads in flexure and shear. The proposed modification shows better approximation of the test results compared to the original models.

• Earthquakes and Structures
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• v.7 no.5
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• pp.877-890
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• 2014

The purpose of this study is to present adequate modeling solutions for squat and slender RC walls. ASCE41-13 (American Society of Civil Engineers) specifies that the aspect ratios of height to width for the RC walls affect the hysteresis response. Thus, this study performed non-linear analysis subjected to cyclic loading using two different macroscopic models: one of macroscopic models represents flexural failure of RC walls (Shear Wall Element model) and the other (General Wall Element model) reflects diagonal shear failure occurring in the web of RC walls. These analytical results were compared to previous experimental studies for a slender wall (> aspect ratio of 3.0) and a squat wall (= aspect ratio of 1.0). For the slender wall, the difference between the two macroscopic models was negligible, but the squat wall was significantly affected by parameters for shear behavior in the modeling method. For accurate performance evaluation of RC buildings with squat walls, it would be reasonable to use macroscopic models that give consideration to diagonal shear.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.411-416
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• 2001

Preliminary experimental results are reported on the response of reversed T type linking reinforced concrete shear wall. Different layouts of coupling beams were tested and stiffness degradation and energy dissipation of coupling beams were evaluated. Diagonally reinforced coupling beams with slab showed larger ductility and larger amount of energy absorption to be attained compared with conventionally reinforced concrete coupled beams.

• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.1065-1074
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• 2005

Due to lack of information, current design methods to calculate bearing strength of connections are tacit about cases in which hybrid coupled walls have connection details of stud bolts and horizontal ties. In this study, analytical study was carried out to develop model for calculating the connections strength of embedded steel section. The bearing stress at failure in the concrete below the embedded steel coupling beam section is related to the concrete compressive strength and the ratio of the width of the embedded steel coupling beam section to the thickness of the shear walls. Experiments were carried out to determine the factors influencing the bearing strength of the connection between steel coupling beam and reinforced concrete shear wall. The test variables included the reinforcement details that confer a ductile behavior in connection between steel coupling beam and shear wall, i. e., the auxiliary stud bolts attached to the steel beam flanges and the transverse ties at the top and the bottom steel beam flanges. In addition, additional test were conducted to verify the strength equations of the connection between steel coupling beam and reinforced concrete shear wall. The results of the proposed equations in this study are in good agreement with both our test results and other test data from the literature.

• Smart Structures and Systems
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• v.20 no.1
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• pp.53-60
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• 2017

Reinforced concrete shear wall is one of the most common structural forms for high-rise buildings, and seismic energy dissipation techniques, which are effective means to control structural vibration response, are being increasingly used in engineering. Reinforced concrete-mild steel damper stiffness-tandem energy dissipation coupling beams are a new technology being gradually adopted by more construction projects since being proposed. Research on this technology is somewhat deficient, and this paper investigates design principles and methods for two types of mild steel dampers commonly used for energy dissipation coupling beams. Based on the conception design of R.C. shear wall structure and mechanics principle, the basic design theories and analytic expressions for the related optimization parameters of dampers at elastic stage, yield stage, and limit state are derived. The outcomes provide technical support and reference for application and promotion of reinforced concrete-mild steel damper stiffness-tandem energy dissipation coupling beam in engineering practice.

• Structural Engineering and Mechanics
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• v.72 no.4
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• pp.443-454
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• 2019

In order to reduce the residual drift of a structure in structural engineering field, a combined structural system (dual) consisting of steel buckling-restrained braced frame (BRBF) along with shear wall is proposed. In this paper, BRBFs are used with special reinforced concrete shear walls as combined systems. Some prototype models of the proposed combined systems as well as steel BRBF-only systems (without walls) are designed according to the code recommendations. Then, the nonlinear model of the systems is prepared using fiber elements for the reinforced concrete wall and appropriate elements for the BRBs. Seismic responses of the combined systems subjected to ground motions at maximum considered earthquake level are investigated and compared to those obtained from BRBFs. Results showed that the maximum residual inter-story drift from the combined systems is, on average, less than half of the corresponding value of the BRBFs. In this research, mean of absolute values of the maximum inter-story drift ratio demand obtained from combined systems is less than the 3% limitation, while this criterion has not been fulfilled by BRBF systems.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.2
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• pp.53-67
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• 2008

In this study, seismic control performance of friction dampers installed in a reinforced concrete shear wall-moment frame system, of which main lateral force resisting system is a shear wall, is investigated. Three configurations of friction dampers are investigated. One is a diagonal brace type reinforcing the shear wall directly, another is a diagonal brace type reinforcing the moment frame without the shear wall, and the other one is a vertical boundary element type installed at both ends of the shear wall. In addition, various levels of the total friction force and its distribution methods are examined. Time history analysis considering material nonlinearity is conducted for seismic loads increased by the enhanced design code compared to the initial design loads, and energy dissipation, lateral loads and structural member damages are analyzed. As a result, the shear wall-reinforcing diagonal brace type with the total friction force of 30 % of the reference friction force gives the best performance on the whole, and the distribution methods of the friction force do not have remarkable difference in effects. Also, concentrated installation in adjacent four stories shows just a little compromised control performance compared to the entire story installation.

• Computational Structural Engineering : An International Journal
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• v.1 no.2
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• pp.117-130
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• 2001

Investigations of low-rice unbounded reinforced concrete shear walls with or without openings are performed with comparison of analytical and experimental results. Theoretical analysis is based on nonlinear finite element algorithm, which incorporates concrete failure criterion and nonlinear constitutive relationships. Studios focus on the effects of height-to-length ratio of shear walls, opening ratio, horizontal and vertical reinforcement radios, and diagonal reinforcement. Analytical solutions conform well with experimental results. Equations for cracking, yielding and ultimate loads with corresponding lateral displacements are derived by regression using analytical results and experimental data. Also, failure modes of low-rise unbounded shear walls are theoretically investigated. An explanation of change in failure mode is ascertained by comparing analytical results and ACI code equations. Shear-flexural failure can be obtained with additional flexural reinforcement to increase a wall's capacity. This concept leads to a design method of reducing flexural reinforcement in low-rise bounded solid shear wall's. Avoidance of shear failure as well as less reinforcement congestion leer these walls is expected.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.113-116
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• 2004

No specific guidelines are for computing the shear strength of steel coupling beam connections embedded in the reinforced concrete shear wall. In this paper, a theoretical study of the strength of hybrid coupled shear wall connections is achieved. The bearing stress at failure in the concrete below the steel coupling beam section is related to the concrete compressive strength and the ratio of the width of the steel coupling beam section to the thickness of the hybrid coupled shear wall. To revise factor affecting shear transfer strength across connections between coupled shear walls and steel coupling beam, experimental studies are achieved. The main test variables were auxiliary details of stud bolts. In this studies, these proposed equations are shown to be in good agreement with the test results reported in the paper and with other test data in the literature.

• Journal of the Earthquake Engineering Society of Korea
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• v.25 no.3
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• pp.137-144
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• 2021

In this study, the seismic safety of nuclear power plant structures is evaluated and verified by performing a vibration test on a relatively simple shear wall structure. The shear walls are the prominent members of nuclear power plants and resist the seismic load. The shear wall structure is designed and manufactured to perform shaking table tests and is used to increase the accuracy of the analytical method by comparing them with the numerical analysis results. Different results will be checked and more efficient application methods will be studied depending on the method of designing reinforced concrete structures.