• Journal of the Earthquake Engineering Society of Korea
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• v.18 no.1
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• pp.53-61
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• 2014

RC shear wall sections which have irregular shapes such as T, ㄱ, ㄷ sections are typically used in low-rise buildings in Korea. Pushover analysis of building containing such members costs a lot of computation time and needs professional knowledge since it requires complicated modeling and, sometimes, fails to converge. In this study, a method using an equivalent column element for the shear wall is proposed. The equivalent column element consists of an elastic column, an inelastic rotational spring, and rigid beams. The inelastic properties of the rotational spring represent the nonlinear behavior of the shearwall and are obtained from the section analysis results and moment distribution for the member. The use of an axial force to compensate the difference in the axial deformation between the equivalent column element and the actual shear wall is also proposed. The proposed method is applied for the pushover analysis of a 5- story shear wall-frame building and the results are compared with ones using the fiber elements. The comparison shows that the inelastic behavior at the same drift was comparable. However, the performance points estimated using the pushover curves showed some deviations, which seem to be caused by the differences of estimated yield point and damping ratios.

• Journal of the Korea Concrete Institute
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• v.25 no.6
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• pp.601-612
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• 2013

In the construction of nuclear power plants using massive walls, the use of high-strength re-bars for shear design is necessary to enhance the constructability and economy. In this study, low-rise walls (aspect ratio of 1.0) with grade 550 MPa bars were tested under cyclic loading to investigate the shear capacity and deformation capacity. The test parameters were the grade of horizontal re-bars (550 MPa, 420 MPa), strength of concrete compressive strength (46 MPa, 70 MPa), horizontal/vertical reinforcement ratio, use of lateral confinement hoops, shape of cross section, and failure modes (shear failure before or after flexural yielding). The test results were compared with those of walls with grade 420 MPa bars and predicted strength by current design codes. The results showed that the shear strength of the walls with 550 MPa bars was comparable to that of the walls with 420 MPa bars though the safe margin slightly decreased. ACI 349 provides underestimated shear strength for the walls with 550 MPa bars. In case of the wall with flexural yielding, a large deformation capacity was achieved. This result indicates that the ACI 349 provisions can be safely applied to seismic design of the low-rise walls (aspect ratio of 1.0) with grade 550 MPa bars.