• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.99-106
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• 2002

This paper presents an analytical investigation on the behavior of simple span integral abutment bridge. An integral abutment bridge is a simple span or multiple span continuous deck type bridge having the deck integral with the abutment wall. Although the temperature variation and earth pressure are the major attributor to the total stress in integral abutment bridge, the superstructure has been designed by modeling it as a simple or continuous beam In order to investigate the effect of temperature change and earth pressure on the superstructure of integral bridge, the simple span integral bridge is modeled as a plane frame element. Performing frame analysis, the variations of bending moment and axial force of superstructure due to the various loading combination are investigated with respect to the flexural rigidity of piles, and the bending moment and axial force obtained by frame analysis are compared with the maximum bending moment obtained by conventional design method and initial prestressing force respectively.

• Steel and Composite Structures
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• 제14권6호
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• pp.621-636
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• 2013

Response modification factor is one of the seismic design parameters to consider nonlinear performance of building structures during strong earthquake, in conformity with the point that many seismic design codes led to reduce the loads. In the present paper it's tried to evaluate the response modification factors of dual moment resistant frame with buckling restrained braced (BRB). Since, the response modification factor depends on ductility and overstrength; the nonlinear static analysis, nonlinear dynamic analysis and linear dynamic analysis have been done on building models including multi-floors and different brace configurations (chevron V, invert V, diagonal and X bracing). The response modification factor for each of the BRBF dual systems has been determined separately, and the tentative value of 10.47 has been suggested for allowable stress design method. It is also included that the ductility, overstrength and response modification factors for all of the models were decreased when the height of the building was increased.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 춘계 학술발표회논문집
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• pp.321-328
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• 2003

The objective of this study is to investigate the seismic response of high-rise RC bearing-wall structures with irregularity. For this purpose, three 1:12 scale 17-story reinforced concrete model structures were constructed according to the similitude law, in which the upper 15 stories have a bearing-wall system while the lower 2-story frames have three different layouts of the plan : The first one is a moment-resisting frame system, the second has a infilled shear wall with symmetric plan and the third has a infilled shear wall with eccentricity, Then, these models were subjected to a series of earthquake excitations. The test results show the followings: 1) the existence of shear wall reduced greatly shear deformation at the piloti frame, but has almost the negligible effect on the reduction of the overturning-moment angle, 2) the frame with shear wall resists most of overturning moment in severe earthquake, 3) the torsional behavior is almost independent of the translational, 4) the absorbed energy due to the overturning deformation has the largest portion in the total absorbed energy.

• 한국공간구조학회논문집
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• 제8권2호
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• pp.85-93
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• 2008

본 연구는 철근콘크리트 특수모멘트골조(SMF)내 보-기둥 접합부의 비탄성 회전능력에 대한 연구결과를 조사한 것이다. 모든 실험체들은 ACI 318-02에 정의된 설계 및 세부지침에 따라 특수모멘트골조로 분류되었다. AISC(2002)기준에서 모멘트골조의 접합부에 대한 내진성능의 만족 기준을 이용하여 보-기둥 접합부를 평가하였다. 총 39개의 실험체들에 대해 자세하게 조사되었다. 특수모멘트골조에 대한 내진설계기준을 만족하는 대부분의 접합부들은 3%의 소성회전까지 휨강도의 심각한 감소 없이 연성이 유지되었다. 이는 특수모멘트골조 접합부들에 대한 엄격한 콘크리트 내진설계 규정에 따른 것으로 조사되었다. 접합부내의 횡방향 보의 존재는 보-기둥 접합부의 구속력과 전단에 대한 저항성을 증가시킨 것으로 조사되었다 접합부 전단응력에 대한 ACI 328-02 제한조건을 만족하는 모든 특수모멘트골조의 접합부들은 요구되는 내진성능을 만족하는 것으로 나타났다.

• Structural Engineering and Mechanics
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• 제28권5호
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• pp.571-585
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• 2008

The purpose of this study is to investigate the linear earthquake behavior of the frame structures including subsoil with different stiffening members and to compare the results of each frame considered. These comparisons are made separately for displacement, bending moments and axial forces for frames with different storey and bay numbers for the time history and the modal analyses. The results of both methods are also compared. The results of the frames with subsoil are also compared with the results of the frames without subsoil. It is concluded that all stiffening members considered in this study decrease the lateral displacement of the frame and the bending moment of the columns and increase the axial force in the columns and that configuration of the bracing members come out to be an important parameter in braced frames since the frames with the same type of bracing give different results depending on configuration. It is also concluded that, in general, the absolute maximum displacements of the frames modeled with subsoil are larger than those of the frames modeled without subsoil.

• Structural Engineering and Mechanics
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• 제45권2호
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• pp.211-232
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• 2013

In this study a multi-objective optimization problem is solved. The objectives used here include simultaneous minimum construction cost in term of sections weight, minimum structural damage using a damage index, and minimum non-structural damage in term of inter-story drift under the applied ground motions. A high-speed and low-error neural network is trained and employed in the process of optimization to estimate the results of non-linear time history analysis. This approach can be utilized for all steel or concrete frame structures. In this study, the optimal design of a planar eccentric braced steel frame is performed with great detail, using the presented multi-objective algorithm with a discrete population and then a moment resisting frame is solved as a supplementary example.

• 한국지진공학회논문집
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• 제9권5호
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• pp.11-19
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• 2005

건축 구조물의 내진 설계는 탄성 정적 방법에 기초하고 있으나, 강진시 구조물의 실제 거동은 비탄성 동적이기 때문에 설계 규준의 적합성을 판단하기 위해서는 비탄성 동적 해석이 요구된다. 본 논문에서는 철근 콘크리트 특수 모멘트 저항 골조 건물을 선택하여 IBC 2003에 따라 설계한 후, 선택된 부재들의 최대 소성 회전, 소산 에너지를 구하여, 건물의 비탄성 거동이 규준에서 의도한 거동을 보이는 지를 검토함과 동시에 층간변위률 요구값을 구하여 설계 한도를 만족하는 지를 조사하였다. 더불어 비횡력 저항 시스템인 내부 모멘트 저항 골조의 해석시 포함 여부의 영향도 함께 조사하였다. 해석 결과 IBC 2003에 의해 설계된 건물은 규준이 의도한 비탄성 거동을 보여주었으며 층간변위률 또한 설계한도를 만족하였다. 그리고, 내부 모멘트 저항 골조는 지진 해석 결과에 중요한 영향을 미치므로 해석 모델에 반드시 포함되어야 함을 알수 있었다.

• 한국지진공학회논문집
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• 제28권2호
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• pp.85-92
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• 2024

This study presents code-compliant seismic details by addressing dry mechanical splices for precast concrete (PC) beam-column connections in the ACI 318-19 code. To this end, critical observations of previous test results on precast beam-column connection specimens with the proposed seismic detail are briefly reported in this study, along with a typical reinforced concrete (RC) monolithic connection. On this basis, nonlinear dynamic models were developed to verify seismic responses of the PC emulative moment-resisting frame systems. As the current design code allows only the emulative design approach, this study aims at identifying the seismic performances of PC moment frame systems depending on their emulative levels, for which two extreme cases were intentionally chosen as the non-emulative (unbonded self-centering with marginal energy dissipation) and fully-emulative connection details. Their corresponding hysteresis models were set by using commercial finite element analysis software. According to the current seismic design provisions, a typical five-story building was designed as a target PC building. Subsequently, nonlinear dynamic time history analyses were performed with seven ground motions to investigate the impact of emulation level or hysteresis models (i.e., energy dissipation performance) on system responses between the emulative and non-emulative PC moment frames. The analytical results showed that both the base shear and story drift ratio were substantially reduced in the emulative system compared to that of the non-emulative one, and it indicates the importance of the code-compliant (i.e., emulative) connection details on the seismic performance of the precast building.

• Steel and Composite Structures
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• 제41권5호
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• pp.747-759
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• 2021

Built-up Double-I (BD-I) columns have been commonly used for mid-rise steel-frame structures in Iran. These columns consist of two hot rolled IPE sections which are connected by two cover plates and fillet welds. Until 2017, BD-I columns were employed in intermediate moment resisting frames (MRF) using welded flange plate (WFP) connections. To evaluate the seismic behavior of the connections, four samples were made and tested based on cyclic loading according to AISC 341-16. It was concluded that typical samples cannot satisfy the seismic provisions related to intermediate MRFs. In contrast, the proposed connections retrofitted with two-part external diaphragms were able to satisfy not only the seismic requirements related to intermediate MRFs but also those related to special MRFs according to AISC. The numerical modeling of these samples was performed using ABAQUS finite element software. This study compared the hysteresis moment-rotation curves, plastic strains, and behavior modes in both experimental samples and numerical models.

• Steel and Composite Structures
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• 제46권3호
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• pp.293-318
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• 2023

This study aims to examine the elastic stiffness properties of Elliptic-Braced Moment Resisting Frame (EBMRF) subjected to lateral loads. Installing the elliptic brace in the middle span of the frames in the facade of a building, as a new lateral bracing system not only it can improve the structural behavior, but it provides sufficient space to consider opening it needed. In this regard, for the first time, an accurate theoretical formulation has been developed in order that the elastic stiffness is investigated in a two-dimensional single-story single-span EBMRF. The concept of strain energy and Castigliano's theorem were employed to perform the analysis. All influential factors were considered, including axial and shearing loads in addition to the bending moment in the elliptic brace. At the end of the analysis, the elastic lateral stiffness could be calculated using an improved relation through strain energy method based on geometric properties of the employed sections as well as specifications of the utilized materials. For the ease of finite element (FE) modeling and its use in linear design, an equivalent element was developed for the elliptic brace. The proposed relation was verified by different examples using OpenSees software. It was found that there is a negligible difference between elastic stiffness values derived by the developed equations and those of numerical analysis using FE method.