• Title/Summary/Keyword: earthquake-resistance design

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A Study on Lateral Bearing Capacity of PHC Piles Driven Vertically in Decomposed Granite and Clayey Soil (화강토와 점토지반에 연직으로 타입된 PHC말뚝의 수평지지력에 관한 연구(지반공학))

  • 문영민;이문수;이대재
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2000.10a
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    • pp.466-470
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    • 2000
  • Recently, the calculation of horizontal bearing capacity of piles foundation has been considered very important for earthquake or wind resistant design in Korea. This study deals with the lateral resistance of PHC pile instead of vertical capacity for earthquake resistant design as well as wind. As case study, the prediction values were compared with measured ones based on ASTM. During this research, Matlock & Reese, Davisson & Gill, Broms and Chang's methods were selected in calculating prediction of lateral resistance of PHC piles. In decomposed granite and clayey soils, The result showed that prediction values proposed by Matlock & Reese(Davisson & Gill), Chang and Broms were smaller values than real values. four proposed methods by Matlock & Reese(Davisson & Gill) and Chang based on lateral deflection and Broms by ultimate lateral resistance turned out valid in view of engineering practice.

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Dynamic shear strength of unreinforced and Hairpin-reinforced cast-in-place anchors using shaking table tests

  • Kim, Dong Hyun;Park, Yong Myung;Kang, Choong Hyun;Lee, Jong Han
    • Structural Engineering and Mechanics
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    • v.58 no.1
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    • pp.39-58
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    • 2016
  • Since the publication of ACI 318-02, the concrete capacity design (CCD) method has been used to determine the resistance of unreinforced concrete anchors. The regulation of steel-reinforced anchors was proposed in ACI 318-08. Until ACI 318-08, the shear resistance of concrete breakout for an unreinforced anchor during an earthquake was reduced to 75% of the static shear strength, but this reduction has been eliminated since ACI 318-11. In addition, the resistance of a hairpin-reinforced anchor was calculated using only the strength of the steel, and a regulation on the dynamic strength was not given for reinforced anchors. In this study, shaking table tests were performed to evaluate the dynamic shear strength of unreinforced and hairpin-reinforced cast-in-place (CIP) anchors during earthquakes. The anchors used in this study were 30 mm in diameter, with edge distances of 150 mm and embedment depths of 240 mm. The diameter of the hairpin steel was 10 mm. Shaking table tests were carried out on two specimens using the artificial earthquake, based on the United States Nuclear Regulatory Commission (US NRC)'s Regulatory Guide 1.60, and the Northridge earthquake. The experimental results were compared to the current ACI 318 and ETAG 001 design codes.

Influence of Joint on Retrofitting Effect by Exterior Steel Frames of Existing RC Buildings (외부접합공법의 내진보강효과에 미치는 접합부의 영향)

  • Ahn, Choong Weon;Min, Chan Gi;Noh, Eun Choul;Han, Hong Soo;Kim, Tae Wan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.4
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    • pp.183-194
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    • 2015
  • In this paper, Nonlinear Static Pushover analysis method(NSP) is proposed which apply to RC buildings reinforced by external retrofit for seismic performance. Based on previous analysis and research, NSP is more developed by connection nonlinearity according to shear resistance mechanism such as dowel and adhesive resistance as major shear resistance elements. According to the proposed method, structural analysis for example buildings was carried out to evaluate seismic performance of buildings. And, it was confirmed that depending on shear strain and characteristics of joint resistant of external retrofitting are different from internal retrofitting. Furthermore, the strength reduction coefficient of the anchor needs to be considered at the joint design.

Earthquake Resistance Capacity of a Typical Bridge by Connection Design (연결부분 설계에 의한 일반교량의 내진성능)

  • Kook, Seung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.23 no.5
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    • pp.543-550
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    • 2010
  • Earthquake resistant design should provide a description of the structural failure mechanism under earthquakes as well as satisfy the requirement of other designs, e.g. design strengths of each structural member should be equal or greater than the required strengths. The reason of such a requirement is the randomness of seimic loads different from other loads. In this study, a typical bridge is selected as an analysis bridge and the procedure is given to get the ductile failure mechanism through connection design. It is shown with the procedure that the earthquake resistant capacity can be ensured within structural member's strengths required by other designs, without cost raise by strength increase of structural members or by use of shock absorbing device e.g. shock transfer unit.

Seismic Analysis of Firefighting Pipe Networks (소방배관 형상에 따른 배관 내진해석)

  • Choi, Ho-Sung;Lee, Jae-Ou
    • Fire Science and Engineering
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    • v.33 no.5
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    • pp.149-154
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    • 2019
  • The stability of firefighting pipes is crucial in the event of an earthquake. In Korea, specification-based designs are used in accordance with NFSC. However, engineering performance-based designs are used for buildings that have special requirements. For firefighting pipes, tree type pipe networks are usually utilized in buildings; however, they are characterized by several limitations. Hence, grid type and loop type networks are being utilized lately. Earthquake-resistant designs for firefighting pipes in Korea utilize NFPA 13 as the cookbook. Nevertheless, an engineering analysis is required to verify its reliability. The NFPA 13 standard used in Korea is a design method for engineers who lack earthquake engineering analysis knowledge of pipes and adapt ASCE and ASME guidelines. Earthquake resistant designs in Korea review braces only. Hence, various analyses under load conditions, such as the internal pressure of a pipe, force exerted by a continuous load, and an earthquake, are required to ensure reliability. An engineering earthquake-resistance analysis showed that tree type pipe networks are less stable than grid and loop type pipe networks. A comparison of earthquake-resistance analysis based on stress and strain revealed that strain analysis exhibited a conservative result value in the range of over-stress. Therefore, for the earthquake-resistance analysis of pipes, it is rational that engineers perform analysis to achieve the required standards through engineering analysis rather than uniform calculations, which should also be analyzed considering various analysis conditions.

Why Worry about Earthquake in Regins of Moderate Seismicity : A Case-Study of Hong Kong

  • Kuang, Jun-Shang
    • Journal of the Earthquake Engineering Society of Korea
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    • v.2 no.3
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    • pp.111-119
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    • 1998
  • This paper reports a part of research work on earthquake resistance consideration in regions of moderate seismicity, which is being carried out in the Department of Civil Engineering, Hong Kong University of Science & Technology. The possible seismic hazard in Hong Kong, which is located in a region of moderate seismicity, is described. A case study is presented to compare the wind and earthquake effects on Hong Kong buildings and to assess whether seismic analysis and desing is necessary for building structure. Potential problems of reinforced concrete buildings under earthquake effects in regions of moderate seismicity are discussed.

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Design Comparison of Totally Prefabricated Bridge Substructure Systems Designed by Present Design and LRFD Methods (현행설계법 및 하중저항계수설계법에 의한 완전 조립식 교량 하부구조의 설계결과 비교)

  • Kim, Tae-Hoon;Kim, Young-Jin;Shin, Hyun-Mock
    • Journal of the Earthquake Engineering Society of Korea
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    • v.15 no.2
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    • pp.11-22
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    • 2011
  • The design comparison and nonlinear analysis of totally prefabricated bridge substructure systems are performed. The prefabricated bridge substructures are designed by the methods of present design and load and resistance factor design (LRFD). For the design, the current Korea Highway Bridge Code (KHBD), with DB-24 and DL-24 live loads, is used. This study evaluates the present design method of KHBD (2005) and AASHTO-LRFD (2007) for totally prefabricated bridge substructure systems. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures, was used.

Fatigue Damage Assessment for Steel Structures Subjected to Earthquake (지진에 대한 강구조물의 피로손상도 추정법)

  • Song, Jong Keol;Yun, Chung Bang;Lee, Dong Guen
    • Journal of Korean Society of Steel Construction
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    • v.9 no.1 s.30
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    • pp.95-105
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    • 1997
  • Structures subjected to strong seismic excitation may undergo inelastic deformation cycles. The resulting cumulative fatigue damage process reduces the ability of structures and components to withstand seismic loads. Yet, the present earthquake resistance design methods focus mainly on the maximum displacement ductility, ignoring the effect of the cyclic responses. The damage parameters closely related to the cumulative damage need to be properly reflected on the aseismic design methods. In this study, two cumulative damage assessment methods derived from the plastic fatigue theory are investigated. The one is based on the hysteretic ductility amplitude, and the other is based on the dissipated hysteretic energy. Both methods can consider the maximum ductility and the cyclic behavior of structural response. The validity of two damage methods has been examined for single degree of freedom structures with various natural frequencies against two different earthquake excitations.

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Seismic Performance of the Framed Apartment Building Structure with Damping System (감쇠시스템을 적용한 라멘조 아파트의 내진성능평가)

  • Chun, Young-Soo;Lee, Bum-Sik;Park, Ji-Young
    • Land and Housing Review
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    • v.8 no.3
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    • pp.181-187
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    • 2017
  • To proactively respond to internal and external changes such as the recent demographic change and rising demand for diversified housing types, this study investigated the framed-structure free plan public house model proposed by the LH to look at the seismic performance of framed-structure apartment according to damper system use through non-linear analysis. The effectiveness thereof was also examined in terms of performance and economy. As a result, the proposed damper system application method to framed-structure free plan public house model was found to meet the performance requirements of the present earthquake-resistant design (KBC2016) and effective to apply to designs. The max response displacement and max response acceleration were compared based on the nonlinear analysis. As a result, the building with damper system showed better earthquake resistance performance than earthquake-resistant structure thanks to the damper system, although the base shear of earthquake-resistant system was reduced by 20% in design. The damper system is expected to help reduce building damage while ensuring excellent earthquake resistance performance. In addition, the framework quantities of earthquake-resistant structure and structure with damping system were compared. As a result, columns were found to reduce concrete amount by about 3.9% and rebar, by about 7.3%. Walls showed about 12.6% reduction in concrete and about 10.7% in rebar. In terms of cost, framework construction cost including formwork and foundation expenses was expected to drop by about 5~6%.

The Estimation of earthquake-resistance for gas utility using Equivalent Static Analysis (가스시설물의 등가정적 해석에 의한 내진성능 평가)

  • Koh J. P.;Hong S. K.;Kim J. H.;Jeong S. Y.
    • Journal of the Korean Institute of Gas
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    • v.6 no.4 s.18
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    • pp.23-32
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    • 2002
  • The purpose of the present study is to analyze the response of Gas Utility subjected to Earthquake and to discuss the failure prediction of Kogas Storage Tank. Initially here, characteristics of Earthquake are reviewed and then earthquake-resistance Design is investigated based on previous earthquake hazard cases. Next, considering the distribution of the transverse permanent ground displacement and equivalent spring constant effect, formulae obtained by a beam theory are established to analyze PeungTak Center Control Room. This analysis was performed without consideration of axial effects. So the finite element analysis was used in order to consider the axial stiffness of Structure.

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