• 제목/요약/키워드: seismic engineering

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Seismic performance assessment of R.C. bridge piers designed with the Algerian seismic bridges regulation

  • Kehila, Fouad;Kibboua, Abderrahmane;Bechtoula, Hakim;Remki, Mustapha
    • Earthquakes and Structures
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    • 제15권6호
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    • pp.701-713
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    • 2018
  • Many bridges in Algeria were constructed without taking into account the seismic effect in the design. The implantation of a new regulation code RPOA-2008 requires a higher reinforcement ratio than with the seismic coefficient method, which is a common feature of the existing bridges. For better perception of the performance bridge piers and evaluation of the risk assessment of existing bridges, fragility analysis is an interesting tool to assess the vulnerability study of these structures. This paper presents a comparative performance of bridge piers designed with the seismic coefficient method and the new RPOA-2008. The performances of the designed bridge piers are assessed using thirty ground motion records and incremental dynamic analysis. Fragility curves for the bridge piers are plotted using probabilistic seismic demand model to perform the seismic vulnerability analysis. The impact of changing the reinforcement strength on the seismic behavior of the designed bridge piers is checked by fragility analysis. The fragility results reveal that the probability of damage with the RPOA-2008 is less and perform well comparing to the conventional design pier.

Evaluation of Seismic performance of RC setback frames

  • Habibi, Alireza;Vahed, Meisam;Asadi, Keyvan
    • Structural Engineering and Mechanics
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    • 제66권5호
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    • pp.609-619
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    • 2018
  • When the irregularities occurred in buildings, affect their seismic performance. This paper has focused on one of the types of irregularities at the height that named setback in elevation. For this purpose, several multistorey Reinforced Concrete Moment Resisting Frames (RCMRFs) with different types of setbacks were designed according to new edition of Iranian seismic code. The nonlinear time history analysis was performed to predict the seismic performance of frames subjected to seven input ground motions. The assessment of the seismic performance was done considering both global and local criteria. Results showed that the current edition of Iranian seismic code needs to be modified in order to improve the seismic behaviour of reinforced concrete moment resisting setback buildings. It was also shown that the maximum damages happen at the elements located in the vicinity of the setbacks. Therefore, it is necessary to strengthen these elements by appropriate modification of Iranian seismic code.

수치해석을 통한 제방 구조물의 내진 안정성에 관한 연구 (A Study on Seismic Stability of Embankment Structure by Numerical Modeling)

  • 신은철;이승택;강현회;류병현
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회 2차
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    • pp.186-191
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    • 2010
  • Recently, it has been reported that number of earthquakes was rapidly increased in the Korean Peninsula. According to the interest of seismic analysis, most of construction design must ensure the stability of structure against risks due to earthquake. Therefore, the ground reinforcement and application of seismic standards is necessary and the new structures must secure a stability about Earthquake under the Korea Seismic Analysis Standards. In this study, the 2D numerical analysis was performed to confirm a seismic stability and analysed that behavior of ground and dykes. The numerical seismic response analyses for dykes and its foundation soil were conducted with considering earthquake modes of short-period and long-period, and artificial seismic wave.

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SEISMIC MONITORING IN SURFACE MINES

  • Ajay Kumar, L.;David Raj, D. Edwin;Renaldy, T. Amrith;Vinoth, S.
    • 터널과지하공간
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    • 제19권3호
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    • pp.174-180
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    • 2009
  • This paper gives a brief review of seismicity and seismic monitoring in surface mines. A summary of various researches related to seismicity is presented. Our research focuses on the understanding of seismicity and the application of analytical techniques to seismicity. Seismic monitoring plays an important role in the identification of potential failure planes and thereby predict potential failures. Much of the instrumentation used in our research is derived from earthquake monitoring systems. The major aspects in seismic monitoring are an instrumentation used, size of the network and data acquisition systems. Seismic monitoring in surface mines could be successfully applied to the improvement of safety standards in slope stability.

Seismic performance evaluation of steel moment frames with self-centering energy-dissipating coupled wall panels

  • Lu Sui;Hanheng Wu;Menglong Tao;Zhichao Jia;Tianhua Zhou
    • Steel and Composite Structures
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    • 제47권5호
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    • pp.663-677
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    • 2023
  • The self-centering energy-dissipating coupled wall panels (SECWs) possess a dual capacity of resiliency and energy dissipation. Used in steel frames, the SECWs can localize the damage of structures and reduce residual drifts. Based on OpenSEES, the nonlinear models were established and validated by experimental results. The seismic design procedure of steel frame with SECW structures (SF-SECW) was proposed in accordance with four-level seismic fortification objectives. Nonlinear time-history response analyses were carried out to validate the reasonability of seismic design procedure for 6-story and 12-story structures. Results show that the inter-story drifts of designed structures are less than drift limits. According to incremental dynamic analyses (IDA), the fragility curves of mentioned-above structure models under different limit states were obtained. The results indicate that designed structures have good seismic performance and meet the seismic fortification objectives.

액체금속로 면진설계를 위한 지침서 개발 (Development of Guidelines for seismic isolation Design of LMR)

  • 유봉;구경회;이재한
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1998년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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    • pp.147-154
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    • 1998
  • The purpose of this paper is to propose the draft guidelines of seismic isolation design of Liquid Metal Reactor (LMR) using high damping laminated rubber bearings. The scopes of guidelines include design requirements of a seismically isolated system and components, seismic isolator, isolation system, interface system between seismic isolation and non-seismic isolation part, qualification and acceptance tests of seismic isolator, seismic isolation reliability, and seismic safety and monitoring system. Proposed guidelines shall be revised to extend to general design guideline for nuclear facilities by further research and discussions.

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Radian of the vault influencing the seismic performances of straight wall arch underground structures

  • Ma, Chao;Lu, Dechun;Qi, Chengzhi;Du, Xiuli
    • Structural Engineering and Mechanics
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    • 제78권5호
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    • pp.637-649
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    • 2021
  • Great efforts have been conducted to investigate the seismic performances of the arch and rectangular underground structures, however, the differences between seismic responses of these two types of underground structures, especially the vault radian influencing the seismic responses of arch structures are not clarified. This paper presents a detailed numerical investigation on the seismic responses of arch underground structures with different vault radians, and aims to illustrate the rule that vault radian affects the seismic responses of underground structures. Five arch underground structures are built for nonlinear soil-structure interaction analysis. The internal forces of the structural components of the underground structures only under gravity are discussed detailedly, and an optimum vault radian for perfect load-carrying functionality of arch underground structures is suggested. Then the structures are analyzed under seven scaled ground motions, amounting to a total of 35 dynamic calculations. The numerical results show that the vault radian can have beneficial effects on the seismic response of the arch structure, compared to the rectangular underground structures, causing the central columns to suffer smaller axial force and horizontal deformation. The conclusions provide some directive suggestions for the seismic design of the arch underground structures.

Parametric seismic evaluation of highway overpass bridges in moderate seismic areas

  • Simon, Jozsef;Vigh, Gergely L.
    • Earthquakes and Structures
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    • 제12권3호
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    • pp.375-388
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    • 2017
  • Prior to modern seismic provisions, several bridges were not designed for seismic actions in moderate seismic areas. Precast multi-girder and slab bridges are typical highway overpass structures; they have a significant contribution to national bridge stocks. Since the seismic behavior is questionable, a preliminary parametric study is conducted to determine critical configurations and components. The results indicate that the behavior of the abutments, backfill soil, superstructure and foundation is normally satisfactory; however, the superstructure-abutment joints are critical for both single- and multi-span bridges, while the piers are also critical for longer multi-span configurations. The parametric results provide a solid basis both for detailed seismic assessment and development of design concepts of newly built structures in moderate seismic zones.

설계스펙트럼의 개정에 따른 철근콘크리트 보통모멘트골조의 내진성능수준 평가 (Performance-Based Evaluation of Seismic Design Proposals for RC Ordinary Moment Frames by Spectrum Revision)

  • 심정은;최인섭;김준희
    • 한국지진공학회논문집
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    • 제26권5호
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    • pp.211-217
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    • 2022
  • New buildings have been designed using different seismic design standards that have been revised. However, the seismic performance of existing buildings is evaluated through the same performance evaluation guidelines. Existing buildings may not satisfy the performance targets suggested in the current guidelines, but there are practical limitations to discriminating the existing buildings with poor seismic performance through a full investigation. In this regard, to classify buildings with poor seismic performance according to the applied standard, this study aimed to evaluate performance-based investigation of the seismic design proposals of buildings with different design standards. The target buildings were set as RC ordinary moment frames for office occupancy. Changes in seismic design criteria by period were analyzed, and the design spectrum changes of reinforced concrete ordinary moment resisting frames were compared to analyze the seismic load acting on the building during design. The seismic design plan was derived through structural analysis of the target model, compared the member force and cross-sectional performance, and a preliminary evaluation of the seismic performance was performed to analyze the performance level through DCR. As a result of the seismic performance analysis through the derived design, the reinforced concrete ordinary moment frame design based on AIK 2000 has an insufficient seismic performance level, so buildings built before 2005 are likely to need seismic reinforcement.

DEVELOPMENT OF SEISMIC DESIGN CODES OF KOREA

  • Chang, Sung-Pil;Kim, Jae-Kwan;Lee, Jae-Hoon
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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    • pp.319-331
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    • 1999
  • The seismic hazard of Korea is briefly described. The seismic design requirements design earthquake levels and design response spectrum that are going to be adopted in the future code system are introduced. Characteristics of ground motion and seismic responses of structures in low to moderate seismicity regions are briefly described. The concept of limited ductility design that seems appropriate for the seismic design in Korea is explained.

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