Statistical analysis of the variation of floor vibrations in nuclear power plants subject to seismic loads

Vilho Jussila, Yue Li, Ludovic Fulop (Corresponding Author)

    Research output: Contribution to journalArticleScientificpeer-review

    1 Citation (Scopus)

    Abstract

    Floor vibration of a reactor building subjected to seismic loads was investigated, with the aim of quantifying the variability of vibrations on each floor. A detailed 3D building model founded on the bedrock was excited simultaneously in three directions by artificial accelerograms compatible with Finnish ground response spectra. Dynamic simulation for 21 s was carried out using explicit time integration. The extracted results of the simulation were acceleration in several floor locations, transformed to pseudoacceleration (PSA) spectra in the next stage. At first, the monitored locations on the floors were estimated by engineering judgement in order to arrive at a feasible number of floor nodes for post processing of the data. It became apparent that engineering judgment was insufficient to depict the key locations with high floor vibrations, which resulted in un-conservative vibration estimates. For this reason, a more systematic approach was later considered, in which nodes of the floors were selected with a more refined grid of 2 m. With this method, in addition to the highest PSA peaks in all directions, the full vibration distribution in each floor can be determined. A statistical evaluation of the floor responses was also carried out in order to define floor accelerations and PSAs with high confidence of non-exceedance. The conclusion was that in-floor variability can be as high as 50-60% and models with sufficiently dense node grids should be used in order to achieve a realistic estimate of floor vibration under seismic action. The effects of the shape of the input spectra, damping, and flexibility of the floors on floor vibration of nuclear power plant buildings were also investigated.
    Original languageEnglish
    Pages (from-to)84-96
    JournalNuclear Engineering and Design
    Volume309
    DOIs
    Publication statusPublished - 2016
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    nuclear power plants
    nuclear power plant
    statistical analysis
    Nuclear power plants
    Loads (forces)
    vibration
    Statistical methods
    grids
    engineering
    bedrock
    estimates
    Vibrations (mechanical)
    damping
    simulation
    confidence
    flexibility

    Keywords

    • data handling
    • floors
    • location
    • nuclear energy
    • nuclear power plants
    • seismology
    • vibrations (mechanical)
    • 3D building models
    • engineering judgement
    • engineering judgments
    • explicit time integration
    • floor accelerations
    • power plant buildings
    • statistical evaluation
    • vibration distributions

    Cite this

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    title = "Statistical analysis of the variation of floor vibrations in nuclear power plants subject to seismic loads",
    abstract = "Floor vibration of a reactor building subjected to seismic loads was investigated, with the aim of quantifying the variability of vibrations on each floor. A detailed 3D building model founded on the bedrock was excited simultaneously in three directions by artificial accelerograms compatible with Finnish ground response spectra. Dynamic simulation for 21 s was carried out using explicit time integration. The extracted results of the simulation were acceleration in several floor locations, transformed to pseudoacceleration (PSA) spectra in the next stage. At first, the monitored locations on the floors were estimated by engineering judgement in order to arrive at a feasible number of floor nodes for post processing of the data. It became apparent that engineering judgment was insufficient to depict the key locations with high floor vibrations, which resulted in un-conservative vibration estimates. For this reason, a more systematic approach was later considered, in which nodes of the floors were selected with a more refined grid of 2 m. With this method, in addition to the highest PSA peaks in all directions, the full vibration distribution in each floor can be determined. A statistical evaluation of the floor responses was also carried out in order to define floor accelerations and PSAs with high confidence of non-exceedance. The conclusion was that in-floor variability can be as high as 50-60{\%} and models with sufficiently dense node grids should be used in order to achieve a realistic estimate of floor vibration under seismic action. The effects of the shape of the input spectra, damping, and flexibility of the floors on floor vibration of nuclear power plant buildings were also investigated.",
    keywords = "data handling, floors, location, nuclear energy, nuclear power plants, seismology, vibrations (mechanical), 3D building models, engineering judgement, engineering judgments, explicit time integration, floor accelerations, power plant buildings, statistical evaluation, vibration distributions",
    author = "Vilho Jussila and Yue Li and Ludovic Fulop",
    note = "SDA: SHP: ForIndustry",
    year = "2016",
    doi = "10.1016/j.nucengdes.2016.09.005",
    language = "English",
    volume = "309",
    pages = "84--96",
    journal = "Nuclear Engineering and Design",
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    }

    Statistical analysis of the variation of floor vibrations in nuclear power plants subject to seismic loads. / Jussila, Vilho; Li, Yue; Fulop, Ludovic (Corresponding Author).

    In: Nuclear Engineering and Design, Vol. 309, 2016, p. 84-96.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Statistical analysis of the variation of floor vibrations in nuclear power plants subject to seismic loads

    AU - Jussila, Vilho

    AU - Li, Yue

    AU - Fulop, Ludovic

    N1 - SDA: SHP: ForIndustry

    PY - 2016

    Y1 - 2016

    N2 - Floor vibration of a reactor building subjected to seismic loads was investigated, with the aim of quantifying the variability of vibrations on each floor. A detailed 3D building model founded on the bedrock was excited simultaneously in three directions by artificial accelerograms compatible with Finnish ground response spectra. Dynamic simulation for 21 s was carried out using explicit time integration. The extracted results of the simulation were acceleration in several floor locations, transformed to pseudoacceleration (PSA) spectra in the next stage. At first, the monitored locations on the floors were estimated by engineering judgement in order to arrive at a feasible number of floor nodes for post processing of the data. It became apparent that engineering judgment was insufficient to depict the key locations with high floor vibrations, which resulted in un-conservative vibration estimates. For this reason, a more systematic approach was later considered, in which nodes of the floors were selected with a more refined grid of 2 m. With this method, in addition to the highest PSA peaks in all directions, the full vibration distribution in each floor can be determined. A statistical evaluation of the floor responses was also carried out in order to define floor accelerations and PSAs with high confidence of non-exceedance. The conclusion was that in-floor variability can be as high as 50-60% and models with sufficiently dense node grids should be used in order to achieve a realistic estimate of floor vibration under seismic action. The effects of the shape of the input spectra, damping, and flexibility of the floors on floor vibration of nuclear power plant buildings were also investigated.

    AB - Floor vibration of a reactor building subjected to seismic loads was investigated, with the aim of quantifying the variability of vibrations on each floor. A detailed 3D building model founded on the bedrock was excited simultaneously in three directions by artificial accelerograms compatible with Finnish ground response spectra. Dynamic simulation for 21 s was carried out using explicit time integration. The extracted results of the simulation were acceleration in several floor locations, transformed to pseudoacceleration (PSA) spectra in the next stage. At first, the monitored locations on the floors were estimated by engineering judgement in order to arrive at a feasible number of floor nodes for post processing of the data. It became apparent that engineering judgment was insufficient to depict the key locations with high floor vibrations, which resulted in un-conservative vibration estimates. For this reason, a more systematic approach was later considered, in which nodes of the floors were selected with a more refined grid of 2 m. With this method, in addition to the highest PSA peaks in all directions, the full vibration distribution in each floor can be determined. A statistical evaluation of the floor responses was also carried out in order to define floor accelerations and PSAs with high confidence of non-exceedance. The conclusion was that in-floor variability can be as high as 50-60% and models with sufficiently dense node grids should be used in order to achieve a realistic estimate of floor vibration under seismic action. The effects of the shape of the input spectra, damping, and flexibility of the floors on floor vibration of nuclear power plant buildings were also investigated.

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    KW - floors

    KW - location

    KW - nuclear energy

    KW - nuclear power plants

    KW - seismology

    KW - vibrations (mechanical)

    KW - 3D building models

    KW - engineering judgement

    KW - engineering judgments

    KW - explicit time integration

    KW - floor accelerations

    KW - power plant buildings

    KW - statistical evaluation

    KW - vibration distributions

    U2 - 10.1016/j.nucengdes.2016.09.005

    DO - 10.1016/j.nucengdes.2016.09.005

    M3 - Article

    VL - 309

    SP - 84

    EP - 96

    JO - Nuclear Engineering and Design

    JF - Nuclear Engineering and Design

    SN - 0029-5493

    ER -