• Title/Summary/Keyword: Earthquake Measures

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Effect of reducing tsunami damage by installing fairing in Kesen-Bridge

  • Abukawa, Takahiro;Nakamura, Yuto;Hasegawa, Akira
    • Earthquakes and Structures
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    • v.7 no.6
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    • pp.1045-1060
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    • 2014
  • The 2011 off the Pacific coast of Tohoku Earthquake brought serious damage around the Tohoku district in Japan, and much human life and fortune were lost. Bridges were damaged by this earthquake. It was the most serious damage that the superstructures of bridges were flowed out by tsunami. Earthquakes of the same scale are predicted in other areas of Japan. It is necessary to take measures for bridges near coast. In order to understand the tsunami force acting on the bridge, hydraulic model experiments was conducted. In addition, this paper focused on fairing that is effective in wind resistant stability. Installing fairing to bridges has been verified by experiments whether it is possible to reduce the force of tsunami.

A Numerical Study on Stress Wave Propagation from Pile Driving (말뚝항타시 발생하는 응력파의 전파특성에 관한 수치해석적 연구)

  • 이종세;임정진
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.09a
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    • pp.123-130
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    • 2002
  • The ground-borne vibration from pile driving is causing many public discontents. However, because of the fact that the characteristics of wave propagation and attenuation are not well understood, systematic and effective vibration reduction measures can not be taken. This paper attempts to study the propagation of stress waves induced by the pile driving. To simulate the wave propagation in a semi-infinite domain, the so-called absorbing boundaries are incorporated in the finite element method and a series of numerical simulations is performed. Numerical results show that the surface displacement and velocity increase first and then decrease as the pile penetration depth becomes larges.

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Considerations and Suggestions for Expressing of Seismic Capacity of Buildings (건축물 내진능력 표현에 관한 고찰 및 제언)

  • Lee, Cheol Ho;Park, Ji-Hun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.20 no.7_spc
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    • pp.517-526
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    • 2016
  • In this paper, some popular intensity measures of earthquakes including magnitude, MMI, and PGA as well as their empirical relationships are briefly reviewed since they have been widely used without prudence by mass media, the public, and even the government when asking or expressing the seismic capacity of buildings. The basic concept of current seismic design is also presented in order to facilitate relevant discussions. It is emphasized that expressing the building seismic capacity simplistically in terms of seismological quantities or terminologies like magnitude and MMI is inherently irrational, may be misleading the stakeholders, and should be avoided. Alternative expressions, more rational and consistent with current seismic design philosophy and practice, are recommended.

the height-wise distribution of lateral seismic forces considering the contribution of the higher modes (고차모드 효과를 고려한 층 지진하중 분배)

  • 황준호
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.10a
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    • pp.273-280
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    • 1999
  • The base shear and the veritcal distribution of shears along the height of a building are two fundamental measures that define the design seismic load. But the method specified in Korean building code does not give an appropriate distribution for buildings of tall or longer period because it roughly account for the contributions of the higher modes. several methods to give a better distribution of seismic forces have been proposed. But they have not been introduced into the seismic codes yet probably because they cannot solve all the above-mentioned problems. This paper deals with the distribution of lateral seismic forces along the height of a building to account for the contribution of the higher modes. After reviewing some existing distributions in seismic codes and literatures moment-resisting frames with various stories were studied by modal analysis for a wide range of fundamental period and the stiffness ratio of the buiding. As a result of the analysis a new expression for the distribution of seismic forces is proposed and compared with those of some codes and dynamic analysis.

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A rapid screening method for selection and modification of ground motions for time history analysis

  • Behnamfar, Farhad;Velni, Mehdi Talebi
    • Earthquakes and Structures
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    • v.16 no.1
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    • pp.29-39
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    • 2019
  • A three-step screening process is presented in this article for selection of consistent earthquake records in which number of suitable ground motions is quickly screened and reduced to a handful number. Records that remain at the end of this screening process considerably reduce the dispersion of structural responses. Then, an effective method is presented for spectral matching and modification of the selected records. Dispersion of structural responses is explored using different statistical measures for each scaling procedure. It is shown that the Uniform Design Method, presented in this study for scaling of earthquake records, results in most cases in the least dispersion measure.

Structural damage potentials and design implications of 2016 Gyeongju and 2017 Pohang earthquakes in Korea

  • Lee, Cheol-Ho;Park, Ji-Hun;Kim, Sung-Yong;Kim, Dong-Kwan;Jun, Su-Chan
    • Earthquakes and Structures
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    • v.22 no.3
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    • pp.305-318
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    • 2022
  • This paper presents a comparative study of the damage potentials for the 2016 Gyeongju and 2017 Pohang earthquakes in Korea. Plausible technical explanations are provided for the more severe damage observed in the 2017 Pohang earthquake in spite of its relatively weaker magnitude and intensity measures based on the response analysis of elastic and inelastic single-degree-of-freedom systems for the recorded ground motions. In addition, a detailed case study was conducted for a fatally damaged piloti building with an eccentric shear wall core based on nonlinear dynamic analysis using the input ground motions modified for the building site.

A Seismic Capacity of R/C Building Damaged by the 2016 Gyeongju Earthquake Based on the Non-linear Dynamic Analysis (비선형동적해석에 의한 2016년 경주지진에서 지진피해를 받은 R/C 건물의 내진성능에 관한 연구)

  • Jung, Ju-Seong;Lee, Kang Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.1
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    • pp.137-146
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    • 2018
  • On September 12, 2016, the Gyeongju District was strongly shaken with M=5.8, which was the largest one since measured by the actual seismometer in Korea, and some buildings were damaged. The field survey of reinforced concrete school buildings in the affected area was carried out, and their residual seismic capacities(R) were estimated based on the Japanese Standard for post-earthquake damage evaluation. In this study, the M school, which was greatly damaged by the 2016 Gyeongju Earthquake, was selected, and its damage level was evaluated on the basis of the Japanese Standard. The seismic capacity of the M school was also evaluated using the nonlinear dynamic analysis, and relationships between its damage level and seismic capacity was also conducted to investigate causes of earthquake damage. The damage level of M school was classified into light with R=88.2%. The result of the dynamic analysis agreed reasonably well with the damage of M school sustained by the 2016 Gyeongju earthquake. This will provide fundamental data for earthquake preparedness measures, such as the seismic rehabilitation of low-rise reinforced concrete buildings in Korea.

Regional Assessment of Seismic Site Effects and Induced Vulnerable Area in Gyeonggi-do, South Korea, Using GIS (GIS 기반 경기도 광역영역의 부지지진응답 특성 및 연계 지진 취약지역 분석)

  • Kim, Han-Saem;Sun, Chang-Guk;Cho, Hyung-Ik;Nam, Jee-Hyun
    • Journal of the Korean Geotechnical Society
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    • v.34 no.5
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    • pp.19-35
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    • 2018
  • The necessity of predicting the spatial information of the site-specific seismic response, which is essential information for the comprehensive earthquake disaster countermeasures, is increasing for the mid-west urban areas where the earthquake-induced damages can be increased due to frequent occurrence of mid-scale earthquake such as 2016 Gyeongju Earthquake and 2017 Pohang Earthquake. Especially, researches on strategic securing of site survey datasets and understanding the site-specific site response characteristics were conducted for Gyeonggi-do, South Korea. In this study, a GIS-based framework for site-specific assessment of site response and induced vulnerable area in Gyeonggi-do, South Korea was proposed. Geo-Data based on GIS platform was constructed for regional estimation of geotechnical characteristics by collecting borehole and land coverage datasets. And the geo-spatial grid information was developed for deriving spatial distribution of geotechnical layer and site response parameters based on the optimization of the geostatistical interpolation method. Accordingly, base information for Improving earthquake preparedness measures was derived as seismic zonation map with administrative sub-units considering the quantitative site effect of Gyeonggi-do.

Framework of seismic design specification for telecommunication (통신설비 적용 내진 규격기준 프레임워크)

  • Lee, Sang-Mu;Cho, Pyung-Dong
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.2
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    • pp.45-52
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    • 2008
  • The telecommunication facilities by the basic law of telecommunication were added to the protection law against natural disasters as a scope of seismic design application on January 2007 since legal regulation had been reinforced in our country as in the circumstance that earthquakes are now frequently occurred in several areas over the world. This paper handles an establishing provision of concrete seismic design specification for applying to telecommunication facilities. For this purpose, this paper classified the parts of telecommunication facilities as being the correspondents to apply seismic design and analyzes the procedure of the design specification of building structure as the part of building construction law as a basic reference for seismic design application. And the method of introducing the foreign specification is presented. Thereon seismic design measures to be introduced into legal regulation are suggested for telecommunication service endurance against earthquake.

A Study on inhabitants self-help scheme via sociotechnology for disaster safety of the smart city - Mainly on lessons of Kamaisi-city in Japan (스마트시티의 재난안전을 위한 사회기술기반의 주민 자조(自助) 방안 고찰 - 일본 가마이시시(釜石市) 교훈을 중심으로)

  • Chang, Hye-Jung;Kim, Do-Nyun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.9 no.4
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    • pp.388-403
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    • 2016
  • On July 5, 2016, offshore magnitude 5.0 earthquake, Ulsan, Republic of Korea can anxiety not safe in the earthquake. The gas smell that occurred in Busan on July 20, 2016 did not understand a cause and spread by the ghost story for the earthquake to a citizen. Thus correct information about the disaster is important to the smart city and the quick correspondence for damage inhabitants and the community has an influence on the disaster resilience. This study is targeted for damage inhabitants, and it clarifies the importance of the evocation model of anxiety about the disaster in the smart city with social technology. In the case of the Great East Japan Earthquake, consider the self-help contents of Kamaishi-city inhabitants deeply and find out a proper application method. As a means of disaster response and recovery, suggest that the inhabitants and community will be able to practice self-help measures.