• 국제초고층학회논문집
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• 제12권3호
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• pp.209-214
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• 2023

Seismic performance-based design methods are widely used in the field of engineering. This paper introduces the current status of seismic performance-based design methods for high-rise buildings in China, and summarizes latest advancements in seismic performance-based design methods for high-rise buildings in China, with a focus on the design methods based on predetermined yield mode and the design methods based on member ductility requirements. Finally, the development direction of seismic performance-based design method for high-rise buildings is prospected.

• 콘크리트학회논문집
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• 제15권5호
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• pp.705-714
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• 2003

우리나라는 선진 외국에 비하여 늦은 1992년에 도로교 표준시방에 내진설계편이 도입되었다. 따라서, 1992년 이전에 설계된 교각들은 내진 설계가 되어있지 않음은 물론 시공편의상 소성힌지 구간에 주철근이 겹침이음 시공되어 현재에도 사용되고 있다. 또한, 현행 내진규정도 강진지역의 설계규정을 도입함으로써 중 약진 지역에 속하는 우리의 현실에 맞지 않아 현장에서 복잡한 철근배근을 요구함으로 시공성 및 경제성이 많이 떨어지고 있는 실정이다. 본 연구에서는 1992년 이전에 비내진 설계/시공되어 공용중인 원형 교각을 조사하여, 주철근이 겹침이음된 기준실험체(주철근비 1.01%, 심부구속철근비 0.13%) 1개를 실물크기와 유사하도록 직경 1.2m, 높이 4.8m로 제작하였으며, 또한 중 약진 지역에 속하는 우리나라의 실정을 감안하여 심부구속철근비를 비내진 규정의의 2.3배 현행 내진 설계규정의 0.32배에 해당하는 0.30%의 한정연성실험체 3개를 제작하여 유사동적 실험을 통하여 내진 연성도 평가를 하였다. 실험결과 비내진 실험체는 요구변위연성도 5를 만족시키지 못하였고, 한정연성 실험체의 경우는 현행 내진규정의 요구 변위연성도 5를 만족하는 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.369-374
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• 2000

This study was conducted to investigate the seismic behavior assessment of circlular-tied bridge piers, particularly with regard to assessing the displacement ductility. The experimental variables of bridge piers test consisted of transverse steel details, amount and spacing different axial load levels etc. The test results indicated that reinforcement concrete bridge piers with confinement steel by the code specification exhibited sufficient ductile behavior and seismic performance. Aldo, it is found that current seismic design code specification of confinement steel requirements may be revised.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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• pp.319-331
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• 1999

The seismic hazard of Korea is briefly described. The seismic design requirements design earthquake levels and design response spectrum that are going to be adopted in the future code system are introduced. Characteristics of ground motion and seismic responses of structures in low to moderate seismicity regions are briefly described. The concept of limited ductility design that seems appropriate for the seismic design in Korea is explained.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.363-368
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• 2000

The Korean Bridge Design Standard Specifications adopted the seismic design requirements in 1992. However, The current seismic design requirements for bridges are based on the USA seismic codes for sever earthquake. This provides the basic factors that affects the performance of spiral reinforced concrete piers for seismic loading, and The specimen tests are performed based on load-displacement, effective stiffness and displacement ductility, etc. The quasi-static test was adopted in order to investigate seismic performance of the spiral reinforced concrete pier specimens which had different transverse steel amount, spacing and longitudinal steel ratio under different axial load levels. This study is concluded that seismic design for transverse reinforcement content of spiral reinforced concrete column has influenced on axial load and effective stiffness etc.

• Earthquakes and Structures
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• 제8권3호
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• pp.713-732
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• 2015

The application of the compressive force path method for the design of earthquake-resistant reinforced concrete structural walls with a shear span-to-depth ratio larger than 2.5 has been shown by experiment to lead to a significant reduction of the code specified transverse reinforcement within the critical lengths without compromising the code requirements for structural performance. The present work complements these findings with experimental results obtained from tests on structural walls with a shear span-to-depth ratio smaller than 2.5. The results show that the compressive force path method is capable of safeguarding the code performance requirements without the need of transverse reinforcement confining concrete within the critical lengths. Moreover, it is shown that ductility can be considerably increased by improving the strength of the two bottom edges of the walls through the use of structural steel elements extending to a small distance of the order of 100 mm from the wall base.

• 콘크리트학회논문집
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• 제15권5호
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• pp.747-758
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• 2003

The moment-curvature envelope describes the changes in the flexural capacity with deformation during a nonlinear analysis. Therefore, the moment-curvature analysis for reinforced concrete columns, indicating the available flexural strength and ductility, can be conducted providing the stress-strain relation for the concrete and steel are known. The moments and curvatures associated with increasing flexural deformations of the column may be computed for various column axial loads by incrementing the curvature and satisfying the requirements of strain compatibility and equilibrium of forces. Clearly it is important to have accurate information concerning the complete stress-strain curve of confined high-strength concrete in order to conduct reliable moment-curvature analysis that assesses the ductility available from high-strength concrete columns. However, it is not easy to explicitly characterize the mechanical behavior of confined high-strength concrete because of various parameter values, such as the confinement type of rectilinear ties, the compressive strength of concrete, the volumetric ratic and strength of rectangular ties. So a stress-strain model is developed which can simulate complete inelastic moment-curvature relations of high-strength concrete columns.

• Earthquakes and Structures
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• 제19권5호
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• pp.361-377
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• 2020

In the present research work, the effectiveness and the efficiency of a retrofitting approach using a layer of ultra-high performance fiber reinforced concrete (UHPFRC) jacket for damaged substandard exterior beam-column joints (BCJs) is experimentally investigated. The main objective of this study is to rehabilitate the already damaged BCJs to meet the serviceability requirements without compromising safety. According to the proposed strengthening technique, a chipped surface, lightly brushed with a dry condition was selected for making a successful bond between normal concrete substrate surface (NCSS) and UHPFRC. Then a fresh UHPFRC jacket with a thickness of 30 mm was cast around the damaged specimens. The entire test matrix was comprised of three 1/3 scale damaged exterior BCJs with a different column axial load (CAL). These specimens were repaired with UHPFRC and retested under monotonic loading. Based on the experimental results, repaired specimens showed an excellent performance in terms of their load-displacement response, maximum strength, displacement ductility, initial stiffness, secant stiffness and energy dissipation capacity when compared with the corresponding values registered when these specimens were tested in their virgin state. This rehabilitative intervention not only restored the strength, stiffness, ductility and energy dissipation capacity of severely damaged specimens but also improved their performance.

• Steel and Composite Structures
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• 제20권3호
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• pp.599-621
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• 2016

In order to study the working mechanism of rectangular steel-concrete composite columns subjected to compression-bending load and further determine the seismic performance index, a bottom strengthened rectangular steel reinforced concrete (SRC) column with concealed steel plates and a bottom strengthened rectangular concrete filled steel tube (CFST) columns were proposed. Six column models with different configurations were tested under horizontal low cyclic loading. Based on the experiments, the load-bearing capacity, stiffness and degradation process, ductility, hysteretic energy dissipation capacity, and failure characteristics of the models were analyzed. The load-bearing capacity calculation formulas for a normal section and an oblique section of bottom strengthened rectangular steel-concrete composite columns were pesented and a finite element (FE) numerical simulation of the classical specimens was performed. The study shows that the load-bearing capacity, ductility, and seismic energy dissipation capacity of the bottom strengthened rectangular steel-concrete composite columns are significantly improved compared to the conventional rectangular steel-concrete composite columns and the results obtained from the calculation and the FE numerical simulation are in good agreement with those from the experiments. The rectangular steel-concrete composite column with bottom strengthened shows better seismic behavior and higher energy dissipation capacity under suitable constructional requirements and it can be applied to the structure design of high-rise buildings.

• Earthquakes and Structures
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• 제20권4호
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• pp.417-430
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• 2021

Due to functional requirements, SRC column-RC beam abnormal joints with characteristics of strong beam weak column, variable column section, unequal beam height and staggered height exist in the Steel reinforced concrete (SRC) frame-bent main building structure of thermal power plant (TPP). This paper presents the experimental results of these abnormal joints through cyclic loading tests on five specimens with scaling factor of 1/5. The staggered height and whether adding H-shaped steel in beam or not were changing parameters of specimens. The failure patterns, bearing capacity, energy dissipation and ductile performance were analyzed. In addition, the stress mechanism of the abnormal joint was discussed based on the diagonal strut model. The research results showed that the abnormal exterior joints occurred shear failure and column end hinge flexural failure; reducing beam height through adding H-shaped steel in the beam of abnormal exterior joint could improve the crack resistance and ductility; the abnormal interior joints with different staggered heights occurred column ends flexural failure; the joint with larger staggered height had the higher bearing capacity and stiffness, but lower ductility. The concrete compression strut mechanism is still applicable to the abnormal joints in TPP, but it is affected by the abnormal characteristics.