• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.243-249
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• 1993

The porpose of this study is to suggest an experimental for shear wall of reinforced concrete wall structure. A series of experimental be performed for earned to strength and deformation property of reinforced concrete shear wall. These specimens are three R/C walls among five models which had boundary. As a result, it was found that cyclic experiment is very proper and cyclic time must be increased 3 or 5 times. Monotonic test results was indicated over 15% than other experiment for yielding strength and ultimate strength.

• Membrane and Water Treatment
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• v.12 no.1
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• pp.37-41
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• 2021

This paper presents the multiscale calculation results of the very fast volume transport in micro/nano cylindrical tubes with the wall slippage. There simultaneously occurs the adsorbed layer flow and the intermediate continuum fluid flow which are respectively on different scales. The modeled fluid is water and the tube wall is somewhat hydrophobic. The calculation shows that the power loss on the tube no more than 1.0 Watt/m can generate the wall slippage even if the fluid-tube wall interfacial shear strength is 1 MPa; The power loss on the scale 104 Watt/m produces the volume flow rate through the tube more than one hundred times higher than the classical hydrodynamic theory calculation even if the fluid-tube wall interfacial shear strength is 1 MPa. When the wall slippage occurs, the volume flow rate through the tube is in direct proportion to the power loss on the tube but in inverse proportion to the fluid-tube wall interfacial shear strength. For low interfacial shear strengths such as no more than 1 kPa, the transport in the tube appears very fast with the magnitude more than 4 orders higher than the classical calculation if the power loss on the tube is on the scale 104 Watt/m.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.3
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• pp.48-54
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• 2022

This research describes a quantitative procedure used to estimate the effect of concrete cracking on stiffness degradation of concrete shear walls and provides analytical references for the seismic design of concrete shear walls. As preliminary research on the seismic response of concrete shear walls, nonlinear transient analysis was performed with commercial FE software. The study presents the nonlinear time history analysis results in terms of concrete damage and cracking behavior induced by seismic input motions. By varying the input motions, concrete strength and shear wall thickness, the seismic responses of a shear wall were examined with nonlinear time history analysis, and the progressive cracking behavior and corresponding hysteresis loop were described. Based on the analysis results, frequency and stiffness degradation of the shear wall from progressive concrete damage and cracking were captured with respect to the seismic levels. The results of this study suggest that stiffness degradation from concrete cracking should be appropriately considered when determining the seismic capacity of RC shear wall structures.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.321-330
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• 2002

This paper presents the experimental results of composite basement wall in which H-pile and reinforced concrete wall are combined using shear connector Twelve specimens are tested to evaluate the shear capacity of the wall. Main variables in the test are composite ratio, distribution of shear connector, thickness of wall, shear-span ratio, and shear reinforcement. Test results indicate that the shear capacity of test specimens varies with the foregoing variables except the composite ratio. The results are compared with strengths predicted using the equations of ACI 318-99, Zsutty, and Bazant. Based on this investigation, a method for predicting the shear strength of composite basement walls is proposed.

• Journal of the Korea Concrete Institute
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• v.21 no.2
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• pp.129-138
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• 2009

Recently, for more demands of the economical benefits and environmental conservation, many engineers prefer to choose remodeling. Artificial openings are often unavoidable to make house wider, which will degrade wall strength and stiffness by losing effective wall section that may cause the weakening of system capacity. In these cases the damaged shear walls need to be retrofitted by additional materials or members. In this research, four specimens were tested to investigate the capacity of the damaged wall and the retrofitted wall. The artificially damaged wall was prestressed by tendons to improve the shear capacity of the wall, and the other walls were retrofitted by adding steel plate at the surface for the same purpose. Consequently, these retrofitted walls had improved capacity and stiffness in both shear and flexure. Especially, the wall with steel plate showed ductile behavior after ultimate load and the prestressed wall had greater stiffness than the unstrengthened prototype wall.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.2
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• pp.93-101
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• 2024

Code-compliant seismic design should be essentially applied to realize the so-called emulative performance of precast concrete (PC) lateral force-resisting systems, and this study developed simple procedures to design precast industrial buildings with intermediate precast bearing wall systems considering both the effect of seismic and blast loads. Seismic design provisions specified in ACI 318 and ASCE 7 can be directly adopted, for which the so-called 1.5S_y condition is addressed in PC wall-to-wall and wall-to-base connections. Various coupling options were considered and addressed in the seismic design of wall-to-wall connections for the longitudinal and transverse design directions to secure optimized performance and better economic feasibility. On the other hand, two possible methods were adopted in blast analysis: 1) Equivalent static analysis (ESA) based on the simplified graphic method and 2) Incremental dynamic time-history analysis (IDTHA). The ESA is physically austere to use in practice for a typical industrial PC-bearing wall system. Still, it showed an overestimating trend in terms of the lateral deformation. The coupling action between precast wall segments appears to be inevitably required due to substantially large blast loads compared to seismic loads with increasing blast risk levels. Even with the coupled-precast shear walls, the design outcome obtained from the ESA method might not be entirely satisfactory to the drift criteria presented by the ASCE Blast Design Manual. This drawback can be overcome by addressing the IDTHA method, where all the design criteria were fully satisfied with precast shear walls' non-coupling and group-coupling strength, where each individual or grouped shear fence was designed to possess 1.5S_y for the seismic design.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.1 s.71
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• pp.63-71
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• 2006

This study presents the effective stiffness-based optimal technique to control Quantitatively lateral drift for shear wall-frame structure system using sensitivity analysis. To this end, the element stiffness matrices are constituted to solve the compatibility problem of displacement degree of freedom between the frame and shear wall. Also, lateral drift constraint to introduce the approximation concept that can preserve the generality of the mathematical programming and can effectively solve the large scaled problems is established. And, the section property relationships for shear wall and frame members are considered in order to reduce the number of design variables and differentiate easily the stiffness matrices. Specifically, constant-shape assumption which is uniformly varying in size during optimal process is applied in frame structure. The thickness or length of shear wall can be changed depending on user's intent. Two types of 20 story shear wall-frame structure system are presented to illustrate the features of the stiffness-based optimal design technique.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.4
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• pp.51-61
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• 2007

A series of three shear wall specimens were tested under constant axial stress and reversed cyclic lateral loading to evaluate the capacity of seismic retrofit proposed for the shear wall with the opening induced by remodeling. One specimen was tested in the as-built condition and the others were retrofitted prior to testing. The retrofit involved the use of carbon fiber sheets and steel plates (thickness ; 3mm) over the entire face of the wall. Specimens were 1/2-scale representations of a one-story wall in a Korean apartment building that was built in 1980. The test results showed that failure mechanism of specimens governed by shear fracture and the strength of specimens was varied with according to the retrofitting strategies.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.1
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• pp.153-162
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• 2007

The purpose of this study is to suggest structural design guidelines in additional shear-wall construction method for apartment remodeling with understanding the effects of the position, length and thickness of the additional walls. The slab-wall frames under seismic loads are analyzed using effective beam width model, which can practically evaluate the structural performance of existing building system. According to the results, proper design guidelines of additional shear-wall construction method(position, length and thickness) is suggested to get the required seismic performance.

• Earthquakes and Structures
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• v.7 no.5
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• pp.667-689
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• 2014

Structural walls (also known as shear walls) are one of the common lateral load resisting elements in reinforced concrete (RC) buildings in seismic regions. The performance of RC structural walls in recent earthquakes has exposed some problems with the existing design of RC structural walls. The main issues lie around the buckling of bars, out-of plane deformation of the wall (especially the zone deteriorated in compression), reinforcement getting snapped beneath a solitary thin crack etc. This study compares performance of a typical wall designed by different standards. For this purpose, a case study RC shear wall is taken from the Hotel Grand Chancellor in Christchurch which was designed according to the 1982 version of the New Zealand concrete structures standard (NZS3101:1982). The wall is redesigned in this study to comply with the detailing requirements of three standards; ACI-318-11, NZS3101:2006 and Eurocode 8 in such a way that they provide the same flexural and shear capacity. Based on section analysis and pushover analysis, nonlinear responses of the walls are compared in terms of their lateral load capacity and curvature as well as displacement ductilities, and the effect of the code limitations on nonlinear responses of the different walls are evaluated. A parametric study is also carried out to further investigate the effect of confinement length and axial load ratio on the lateral response of shear walls.