• Journal of the Earthquake Engineering Society of Korea
• /
• v.18 no.4
• /
• pp.181-191
• /
• 2014

This research presents the nonlinear analysis model for reinforced concrete shear wall systems with special boundary elements as proposed by the Korean Building Code (KBC, 2009). In order to verify the analysis model, analytical results were compared with the experimental results obtained from previous studies. Established analytical model was used to perform nonlinear static and dynamic analyses. Analytical results showed that the semi-special shear wall improved significantly the performance in terms of ductility and energy dissipation as expected based on previous test results. Furthermore, nonlinear incremental dynamic analysis was performed using 20 ground motions. Based on computer analytical results, the ordinary shear wall, special shear wall and newly proposed semi-special shear wall systems were evaluated based on the methods in FEMA P965. The results based on the probabilistic approaches accounting for inherent uncertainties showed that the semi-special shear wall systems provide a high capacity/demand (ACMR) ratio owing to their details, which provide enough capacity to sustain large inelastic deformations.

• Earthquakes and Structures
• /
• v.8 no.3
• /
• pp.761-778
• /
• 2015

The objective of this paper is to report the result of an experimental program conducted on the strengthening of nonductile RC frames by using external mesh reinforcement and plaster application. The main objective was to test an alternative strengthening technique for reinforced concrete buildings, which could be applied with minimum disturbance to the occupants. Generic specimen is two floors and one bay RC frame in 1/2 scales. The basic aim of tested strengthening techniques is to upgrade strength, ductility and stiffness of the member and/or the structural system. Six specimens, two of which were reference specimens and the remaining four of which had deficient steel detailing and poor concrete quality were strengthened and tested in an experimental program under cyclic loading. The parameters of the experimental study are mesh reinforcement ratio and plaster thickness of the infilled wall. The effects of the mesh reinforced plaster application for strengthening on behavior, strength, stiffness, failure mode and ductility of the specimens were investigated. Premature and unexpected failure mode has been observed at first and second specimens failed due to inadequate plaster thickness. Also third strengthened specimen failed due to inadequate lap splice of the external mesh reinforcement. The last modified specimen behaved satisfactorily with higher ultimate load carrying capacity. Externally reinforced infill wall composites improve seismic behavior by increasing lateral strength, lateral stiffness, and energy dissipation capacity of reinforced concrete buildings, and limit both structural and nonstructural damages caused by earthquakes.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.04a
• /
• pp.683-688
• /
• 1999

The purpose of this study is to develop and evaluate the structural performance of various shear walls, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility etc. under load reversals. For the diagonal reinforced slit and infilled shear wall specimens, it was found that the failure mode shows very effective crack control and crashing due to slippage prevention of boundary region and reduction of diagonal tension rather than the brittle shear and diagonal tension failure. The ductility of specimens designed by the diagonal reinforcement for the slit and infilled shear wall was increased 1.72~1.81 times in comparison with the fully rigid shear wall frame. Maximum horizontal load-carrying capacity of specimens designed by the diagonal reinforcement ratio the slit and infilled shear wall was increased respectively by 1.14 times and 1.49 times in comparison with the standard fully rigid shear wall frame.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.05a
• /
• pp.159-160
• /
• 2019

Reinforced concrete construction is one of the labor intensive construction projects and its productivity is very low. It is necessary to increase the productivity of rebar construction for improving the productivity of construction work. Therefore, in this study, the rebar drawings of apartment buildings are analyzed to prefabricate wall rebar unit shaped mesh in the factory and installing it on site. If the proposed wall rebar unit is applied to apartment construction working time of wall rebar can be reduced by 50% or more.

• Earthquakes and Structures
• /
• v.20 no.3
• /
• pp.309-323
• /
• 2021

Architectural design decisions and structural systems arrangements affect their earthquake behaviors significantly of reinforced concrete building in Turkey. Because the performances as safe and economical against earthquake loads of reinforced concrete buildings can be provided with especially design decisions in the architectural design stage. This matter reveals the importance of design decisions in the architectural design phase and the right structural system arrangement. The purpose of this study, the short-column situation frequently observed in reinforced concrete buildings after the earthquakes occurred in Turkey are to examine comparatively the effects on behavior and the rough construction cost of the building. The obtained results show that the short column circumstance composed due to different reasons negatively affects the earthquake performance of the reinforced concrete buildings and increases the rough construction cost. This matter shows that the measures to be taken against short column formation should be foreseen especially at the architectural design stage.

• Earthquakes and Structures
• /
• v.16 no.3
• /
• pp.329-348
• /
• 2019

The main objective of this experimental research was to investigate the Seismic performance of reinforced concrete frames infilled with perforated clay brick masonry wall of a type commonly used in Algeria. Four one story-one bay reinforced concrete infilled frames of half scale of an existing building were tested at the National Earthquake Engineering Research Center Laboratory, CGS, Algeria. The experiments were carried out under a combined constant vertical and reversed cyclic lateral loading simulating seismic action. This experimental program was performed in order to evaluate the effect and the contribution of the infill masonry wall on the lateral stiffness, strength, ductility and failure mode of the reinforced concrete frames. Numerical models were developed and calibrated using the experimental results to match the load-drift envelope curve of the considered specimens. These models were used as a bench mark to assess the effect of normalized axial load on the seismic performance of the RC frames with and without masonry panels. The main experimental and analytical results are presented in this paper.

• Advances in Computational Design
• /
• v.8 no.1
• /
• pp.37-59
• /
• 2023

Squat reinforced concrete (SRC) shear walls are a critical part of the structure for both office/residential buildings and nuclear structures due to their significant role in withstanding seismic loads. Despite this, empirical formulae in current design standards and published studies demonstrate a considerable disparity in predicting SRC wall shear strength. The goal of this research is to develop and evaluate hybrid and ensemble artificial neural network (ANN) models. State-of-the-art population-based algorithms are used in this research for hybrid intelligence algorithms. Six models are developed, including Honey Badger Algorithm (HBA) with ANN (HBA-ANN), Hunger Games Search with ANN (HGS-ANN), fitness-distance balance coyote optimization algorithm (FDB-COA) with ANN (FDB-COA-ANN), Averaging Ensemble (AE) neural network, Snapshot Ensemble (SE) neural network, and Stacked Generalization (SG) ensemble neural network. A total of 434 test results of SRC walls is utilized to train and assess the models. The results reveal that the SG model not only minimizes prediction variance but also produces predictions (with R²= 0.99) that are superior to other models.

• Magazine of the Korea Concrete Institute
• /
• v.24 no.3
• /
• pp.41-44
• /
• 2012

• Magazine of the Korea Concrete Institute
• /
• v.23 no.1
• /
• pp.69-72
• /
• 2011

• Computers and Concrete
• /
• v.2 no.2
• /
• pp.111-123
• /
• 2005

The ductility of reinforced concrete bearing walls subjected to high axial loading and moment can be enhanced by improving the deformability of the compression zone or by reducing the neutral axis depth. The current state-of-the-art procedure evaluating the confinement effect prompts a consideration of the spaces between the transverse and longitudinal reinforcing bars, and a provision of tie bars. At the same time, consideration must also be given to the thickness of the walls. However, such considerations indicate that the confinement effect cannot be expected with the current practice of detailing wall ends in Korea. As an alternative, a comprehensive method for dimensioning boundary elements is proposed so that the entire section of a boundary element can stay within the compression zone when the full flexural strength of the wall is developed. In this comprehensive method, the once predominant code approach for determining the compression zone has been advanced by considering the rectangular stress block parameters varying with the extreme compression fiber strain. Moreover, the size of boundary elements can also be determined in relation to the architectural requirement.