• Title/Summary/Keyword: Design earthquake

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A Study on the contact surface of Stem and Bellows of Gate Valve in Nuclear Power Plants (원자력발전소 게이트밸브의 스템 - 벨로우즈 접촉면에 관한 연구)

  • Ko, Seok-Hoon;Shim, Dong-Hyouk;Kim, Dae-Youl;Choi, Myung-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.1044-1048
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    • 2006
  • Nuclear power generation is very dangerous in occasion that skirt of structure by earthquake although it is high effective generation that can make a lot of energies with few raw material. when design, it must consider a lot of problems caused by an earthquake. The seismic analysis of the structure has been great concern in the engineering society with an effort to reduce the severe damages from an earthquake. So the earthquake resistant design is one of the crucial design procedures of a gate valve used in nuclear power generation. The gate valve which has the contact area between stem and bellows. Because of the contact area. The gate valve should be given high stress and frictional wear. In this thesis, Considering the gate valve which has some contact distance between stem and bellows. The gate valve which has some contact distance is analyzed by a commercial FEM code of Ansys and Then compared to the gate valve behavior which doesn't have contact distance.

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Displacement Ductility Based Seismic Performance Evaluation of Circular RC Bridge Piers (변위연성도 기반 원형철근콘크리트 교각의 내진성능 평가)

  • Park, Chang-Kyu;Lee, Dae-Hyoung;Yun, Sang-Chul;Chung, Young-Soo
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.276-283
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    • 2006
  • Korea is considered to be immune from the earthquake hazard because it is located far away from the active fault. However, recent earthquake caused a loss of lives and economical loss worldwide. Hence there has been raised an importance of the earthquake resistant design for various infrastructures. In this research, the seismic design and evaluation criterion for RC bridge pier were proposed from the experimental results of 82 circular RC bridge piers tested in domestic and aboard. New seismic criterion was introduced the limited ductile design provision suitable to Korean peninsula, which would be classified as a low or moderate seismic region. In addition, further important topic for the seismic safety of RC bridge piers in Korea is the seismic performance enhancement of RC bridge piers, which were designed and constructed before the 1992 seismic design provision. Therefore, the proposed seismic performance evaluation criterion could be very useful to judge seismic retrofit need or not according to the residual seismic performance of the RC bridge piers. Also, it could reduce an uncertainty for the safety of the infrastructure under earthquakes.

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Seismic Collapse Risk for Non-Ductile Reinforced Concrete Buildings According to Seismic Design Categories (비연성 철근콘크리트 건물의 내진설계범주에 따른 붕괴 위험성 평가)

  • Kim, Minji;Han, Sang Whan;Kim, Taeo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.25 no.4
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    • pp.161-168
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    • 2021
  • Existing old reinforced concrete buildings could be vulnerable to earthquakes because they were constructed without satisfying seismic design and detail requirements. In current seismic design standards, the target collapse probability for a given Maximum Considered Earthquake (MCE) ground-shaking hazard is defined as 10% for ordinary buildings. This study aims to estimate the collapse probabilities of a three-story, old, reinforced concrete building designed by only considering gravity loads. Four different seismic design categories (SDC), A, B, C, and D, are considered. This study reveals that the RC building located in the SDC A region satisfies the target collapse probability. However, buildings located in SDC B, C, and D regions do not meet the target collapse probability. Since the degree of exceedance of the target probability increases with an increase in the SDC level, it is imminent to retrofit non-ductile RC buildings similar to the model building. It can be confirmed that repair and reinforcement of old reinforced concrete buildings are required.

Seismic Fragility of Low-rise Piloti Buildings Designed According to KDS 41 17 00 (KDS 41 17 00에 따라 설계된 저층 필로티 건물의 지진 취약도)

  • Joo, Changhyeok;Kim, Taewan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.26 no.2
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    • pp.49-58
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    • 2022
  • The 2017 Pohang earthquake caused severe damage to low-rise piloti buildings. The damage was caused mainly by column shear failure, and some core walls were as well. The damaged piloti buildings in Pohang City could be relieved if they were designed correctly according to the standards at that time. However, the post-earthquake investigation revealed design, construction, and permission problems. To solve the problems, the Piloti Building Structure Design Guidelines that include strict specifications were published in 2018. Separately, KDS 41 17 00, the seismic design standard for buildings, was enacted in 2019 and it included the guideline contents. Therefore, at least after the publication of the guidelines, piloti buildings, designed by the standard and guidelines, can be expected to possess better seismic performance than existing piloti buildings. To confirm this, the probability of exceedance for several damage state thresholds was estimated for existing and designed piloti buildings. As a result, the probability of damage of designed piloti buildings was very low compared to existing ones. Consequently, it was confirmed that the guideline and standard adequately supplement the structural fragility of existing piloti buildings.

Seismic Design Method for Structural Walls Based on Energy Dissipation Capacity (에너지 소산능력을 고려한 전단벽의 내진설계)

  • 박홍근;엄태성;정연희
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.09a
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    • pp.247-257
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    • 2002
  • Recently, performance-based analysis/design methods such as the capacity spectrum method and the direct displacement-based design method were developed. In these methods, the estimation of energy dissipation capacity due to inelastic behavior of RC structures depends on empirical equations which are not sufficiently accurate. On the other hand, in a recent study, a simplified method for evaluating energy dissipation capacity was developed. In the present study, based on the evaluation method, a new seismic design method for flexure-dominated RC walls is developed. In determination of seismic earthquake load, the proposed design method can address variation of the energy dissipation capacity with design parameters such as dimensions and shapes of cross-sections, axial force, and reinforcement ratio and arrangement. The proposed design method is compared with the current performance-based design methods and the applicability of the proposed method is disscussed.

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Seismic Response Analysis of Wind-Designed Concentrically Braced Steel Highrise Buildings (내풍설계된 초고층 철골중심가새골조의 지진응답 해석)

  • 이철호;김선웅
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.10a
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    • pp.60-67
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    • 2004
  • The designer of a tall building even in moderate and low seismic regions should, in finalizing the desist consider the probable impact of the design basis earthquake on the selected structural system. In this study, seismic response analysis was conducted to evaluate the seismic performance of concentrically braced steel highrise buildings which were designed only for governing wind loading under moderate seismicity. The main purpose of this analysis was to see if the wind design would create a system whose elastic capacity clearly exceeds the probable demand as suggested by the design basis earthquake. The strength demand-to-capacity study revealed that the wind-designed steel highrise buildings with the aspect ratio of larger than five can withstand the design basis earthquake elastically by a sufficient margin due to the system over-strength resulting from the wind-serviceability criterion. The maximum story drift demand from the design basis earthquake was just 0.25% (or half the limit of Immediate Occupancy performance level in FEMA 273)

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Seismic Response of R/C Structures Subjected to Artificial Ground Motions Compatible with Design Spectrum (설계용 스펙트럼에 적합한 인공지진동을 입력한 철근콘크리트 구조물의 지진응답 특성의 고찰)

  • Jun, Dae-Han;Kang, Ho-Geun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.12 no.1
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    • pp.1-9
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    • 2008
  • In seismic response analysis of building structures, the input ground accelerations have considerable effect on the nonlinear response characteristics of structures. The characteristics of soil and the locality of the site where those ground motions were recorded affect on the contents of earthquake waves. Therefore, it is difficult to select appropriate input ground motions for seismic response analysis. This study describes a generation of artificial earthquake wave compatible with seismic design spectrum, and also evaluates the seismic response values of multistory reinforced concrete structures by the simulated earthquake motions. The artificial earthquake wave are generated according to the previously recorded earthquake waves in past major earthquake events. The artificial wave have identical phase angles to the recorded earthquake wave, and their overall response spectra are compatible with seismic design spectrum with 5% critical viscous damping. The input ground motions applied to this study have identical elastic acceleration response spectra, but have different phase angles. The purpose of this study is to investigate their validity as input ground motion for nonlinear seismic response analysis. As expected, the response quantifies by simulated earthquake waves present better stable than those by real recording of ground motion. It was concluded that the artificial earthquake waves generated in this paper are applicable as input ground motions for a seismic response analysis of building structures. It was also found that strength of input ground motions for seismic analysis are suitable to be normalize as elastic acceleration spectra.

The Nature of Earthquake and Earthquake Resistant Building Design (지진의 성격과 건축물 내진설계에 대하여)

  • 양완수
    • Journal of the Korean Professional Engineers Association
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    • v.28 no.2
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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.

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Determination of seismic hazard and soil response of a critical region in Turkey considering far-field and near-field earthquake effect

  • Sonmezer, Yetis Bulent;Celiker, Murat
    • Geomechanics and Engineering
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    • v.20 no.2
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    • pp.131-146
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    • 2020
  • Evaluation of earthquake impacts in settlements with a high risk of earthquake occurrence is important for the determination of site-specific dynamic soil parameters and earthquake-resistant structural planning. In this study, dynamic soil properties of Karliova (Bingol) city center, located near to the intersection point of the North Anatolian Fault Zone and the East Anatolian Fault Zone and therefore having a high earthquake risk, were investigated by one-dimensional equivalent linear site response analysis. From ground response analyses, peak ground acceleration, predominant site period, 0.2-sec and 1-sec spectral accelerations and soil amplification maps of the study area were obtained for both near-field and far-field earthquake effects. The average acceleration spectrum obtained from analysis, for a near-field earthquake scenario, was found to exceed the design spectra of the Turkish Earthquake Code and Eurocode 8. Yet, the average acceleration spectrum was found to remain below the respective design spectra of the two codes for the far-field earthquake scenario. According to both near- and far-field earthquake scenarios in the study area, the low-rise buildings with low modal vibration durations are expected to be exposed to high spectral acceleration values and high-rise buildings with high modal vibration durations will be exposed to lower spectral accelerations. While high amplification ratios are observed in the north of the study area for the near-distance earthquake scenario, high amplification ratios are observed in the south of the study area for the long-distance earthquake scenario.

Seismic Design of an Arch Bridge (아치교의 내진설계)

  • 국승규
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1997.04a
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    • pp.101-106
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    • 1997
  • In order to check the safety against earthquakes a seismic design of an arch bridge is carried out in this study according to the Division V (Seismic Design) of the "Standard for the Roadway Bridges", where the application procedures including the determination of coefficients, the analysis method as well as the safety checks are provided. provided.

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