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 - 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

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SP - 84

EP - 96

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JF - Nuclear Engineering and Design

SN - 0029-5493

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