• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1991년도 가을 학술발표회 논문집
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• pp.90-95
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• 1991

The Uniform Building Code (UBC) is the most widely used requirements for earthquake resistant design in the United States. In this paper, a mid-rise steel building is analyzed by applying 12 sets of actual strong-motion earthquake data that have been scaled to acne 2B levels. The simply extrapolated ground motion displacements are used for the dynamic loads. The results of dynamic analyses for a 10-story steel building are compared with the static and dynamic analysis requirements of UBC-88. It was found that computed lateral fortes using UBC-88 static procedure differed by about 60 percent depending on whether the natural period was computed using the UBC empirical method or the UBC recommended Rayleigh's method. The lateral fortes computed from the UBC response spectra were more than 10 times greater than those computed by UBC static procedures. The lateral forces obtained from both linear and nonlinear analyses using 1989 Loma Prieta ground mot ions compared very well with UBC response spectra results.

• 전산구조공학
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• 제8권3호
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• pp.113-122
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• 1995

이 논문의 목적은 현행법규(Uniform Buidling Code, NEHRP 설계규준 등)에 따라 설계된 구조들의 성능 및 안정성을 평가하는데 있다. 구조물의 내진성능은 신뢰성으로 표현할 수 있다. 구조물의 그의 수명동안 내진에 대한 신뢰성 해석을 하기 위해서는 주어진 구조물들의 많은 양의 동적반응 해석을 요구하는 것이 일반적이다 따라서 구조물의 신뢰성 해석을 위하여 구조물이 위치한 지역에 많은 양의 지진기록들이 요구된다. 이 논문에서는 인위적인 지진들(artificial earthquakes)을 부정착 임계 파정법(nonstationary randon process)을 이용해 만들었고 구조물은 Uniform Building Code와 AISC 허용응력 설계지침서(AISC allowables stress design manual)에 따라서 설계하였다. 이 논문에서는 주어진 지진하중에 대한 구조물의 반응은 구조물의 비선형 반응해석과 반응변위수정계수들을 이용한 간략화된 동위 구조물 해석(ENS)으로 얻었다. 이 논문에서는 구조물의 내진성능을 평가하였다. 또한 동위구조물(Equivalent Nonlinear System (ENS))을 이용한 해석과 구조물의 비선형 반응해석의 결과들을 비교하여 동위구조물을 이용한 방법의 정확성도 령가하였다.

• Earthquakes and Structures
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• 제12권1호
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• pp.91-108
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• 2017

Superstructures and isolation systems of seismically isolated buildings located close to active faults may observe increased seismic demands resulting from long-period and high-amplitude velocity and displacement pulses existent in near-fault ground motions as their fundamental periods may be close to or coincident with these near-fault pulse periods. In order to take these effects into account, the 1997 Uniform Building Code (UBC97) has specified near-source factors that scale up the design spectrum depending on the closest distance to the fault, the soil type at the site, and the properties of the seismic source. Although UBC97 has been superseded by the 2015 International Building Code in the U.S.A., UBC97 near-source factors are still frequently referred in the design of seismically isolated buildings around the world. Therefore it is deemed necessary and thus set as the aim of this study to assess the necessity and the adequacy of near-source factors for seismically isolated buildings. Benchmark buildings of different heights with isolation systems of different properties are used in comparing seismic responses obtained via time history analyses using a large number of historical earthquakes with those obtained from spectral analyses using the amplified spectrums established through UBC97 near-source factors. Results show that near-source factors are necessary but inadequate for superstructure responses and somewhat unconservative for base displacement response.

• Structural Engineering and Mechanics
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• 제23권5호
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• pp.543-562
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• 2006

Base isolation technology has been accepted as a feasible and attractive way in improving seismic resistance of structures. The seismic design of new seismically isolated structures is mainly governed by the Uniform Building Code (UBC-97) published by the International Conference of Building Officials. In the UBC code, the distribution formula of the inertial (or lateral) forces leads to an inverted triangular shape in the vertical direction. It has been found to be too conservative for most isolated structures through experimental, computational and real earthquake examinations. In this paper, four simple and reasonable design formulae, based on the first mode of the base-isolated structures, for the lateral force distribution on isolated structures have been validated by a multiple-bay three-story base-isolated steel structure tested on the shaking table. Moreover, to obtain more accurate results for base-isolated structures in which higher mode contributions are more likely expected during earthquakes, another four inertial force distribution formulae are also proposed to include higher mode effects. Besides the experimental verification through shaking table tests, the vertical distributions of peak accelerations computed by the proposed design formulae are in good agreement with the recorded floor accelerations of the USC University Hospital during the Northridge earthquake.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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• pp.188-195
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• 1998

The seismic design guidelines for the pile-supported marginal wharf structures are studied. Various design codes such as AASHTO code or UBC code, which are focused on general structures, may be referred for the design of the wharf structures. However, in developing domestic design code, special consideration should be made concerning the size of the earthquake and the type of the structure. This study aims at the comparison among the various design codes for a specific wharf structure in the process of developing a domestic design code.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1991년도 가을 학술발표회 논문집
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• pp.81-89
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• 1991

Recently increasing number of highrise buildings are aseismically designed by dynamic analysis method. To perform comparative study on the results of seismic design by dynamic analysis method, five-to thirty-story building models of ductile moment resisting frames and braced frames are considered. Base shears of these models using the spectrum of equivalent static method in the current Korean code and the ones of dynamic analysis method in the UBC-88 code are compared. Based on this study design spectra to be used in the dynamic analysis in Korea are proposed and the results are compared.

• Structural Engineering and Mechanics
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• 제87권4호
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• pp.347-361
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• 2023

This research aims to assess the behavior of reinforced concrete (RC) residential buildings when moment-resisting frames (MRFs) are used as the lateral resisting system. This investigation was conducted using MIDAS Gen v.19.0. Buildings with various plan footprints (Square, Rectangular, Circular, Triangular, and Plus-Shaped), and different heights (15 m, 30 m, 45 m, and 60 m) are investigated. The defined load cases, the equivalent static lateral load pattern, and the response spectrum function were defined as stated by the American Standard (ASCE 7-16), the 1997 Uniform Building Code (UBC97), the Egyptian Code for Loads (ECP-201), and the European Standard (EC8). Extensive comparisons of the results obtained by the different codes (including the story displacement, the story drift, and the base shear) were undertaken; to assess the response of moment-resisting multi-story framed buildings under lateral loads. The results revealed that, for all study cases under consideration, both ECP-201 and EC8 gave smaller base shear, displacement, and drift by one third to one fourth, around one fourth, around one fifth, respectively for both the ELF and RSA methods if compared to ASCE 7-16 and UBC97.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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• pp.212-219
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• 1999

In this paper we investigated an applicability of earthquake regulations for seismic-isolated building structures which has been used currently and propose an efficient method for vertical distribution of seismic loads. The distribution of force is revised in UBC-94 as vertical distribution of force of UBC(Uniform Building Code)-91 is not sufficient safety but its distribution is inefficient expensive because of similar expression to fixed-based structures. In order to overcome this difficulties improved vertical distribution to fixed-based structures. In order to overcome this difficulties improved vertical distribution of seismic load is proposed using two degrees-of-freedom isolated structures and mode shape of fixed-based structures. Efficiency and accuracy of the proposed method are verified through analysis of an example structures with moment resisting frame and shear walls so this study approximate to dynamic analysis results in each case.

• Structural Engineering and Mechanics
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• 제9권3호
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• pp.257-268
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• 2000

The seismic design recommendations of the Jordan Code for Loads and Forces (JC) are evaluated, based on comparisons with analytical studies and the Uniform Building Code. It was established that the overall safety ensured by the implementation of these recommendations is not consistent with the established seismic risk in Jordan and the intended objectives of the code. A new zoning map is proposed with effective peak ground acceleration values. The different period formulae of the code were studied and were found to grossly underestimate the fundamental period when compared with analytically derived values or other codes' formulae. Other factors including the dynamic, soil, importance and behavior factors are discussed. It was determined that the JC's lateral load distribution formulae clearly lead to smaller internal forces than both dynamic analysis and UBC loads, even when those loads are normalized to give the same base shear. The main reason for this is attributed to the limited allowance for a backlash force in the JC.

• 기술사
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• 제28권2호
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• pp.13-20
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• 1995

This paper Is to help the structural engineers for a better understanding of "Earthquake" with regard to the nature o( earthquake and the effect of earthquake on building structures. This reveals that the damage Inflicted upon by earthquake varies with many factors such as : magnitude of earthquake, distance from epicenter, site conditions, building structural characteristics and etc.. It is emphasized that in order to resist very strong earthquake, the ductility demand in the building structure Is important, and the proper duc-tility enables the structure to demonstrate inelastic rotation capacity of the joints and thus the structure may absorb and dissipate the seismic energy. This also presents a comparison between the current Americal UBC Code and the Korean Code, and the author expresses some points of concern on each code. Since earthquake almost invariably strikes at times and places, it is suggested that the current Korean Build-ing Code should be revised to enforce more stringent regulation against possible strong earthquake in the Korean peninsula.