CSA N289.3-2020 pdf free download

CSA N289.3-2020 pdf free download.Design procedures for seismic qualification of nuclear power plants.
site conditions and other factors such as near-fault (source to site distance less than 15 km) considerations. V/H can be near unity for rock sites at low frequencies (≤ 1 Hz), and near unity at frequencies  5 Hz for near-fault conditions.
4.3.4 Site-specific ground response spectra
For design of new plants, site-specific ground response spectra for different annual probabilities of exceedance and with different confidence levels are typically determined during PSHA for a site (see CSA N289.2). Alternatively, the following procedure may be used for generating site-specific ground response spectra for the specific site based on time-histories recorded at the site or a site with similar geology, geophysics, and seismicity:
Note: Design response spectra may be derived from the site-specific response spectra via smoothing and amplification factors reflecting site seismicity, Section 2.0 of ASCE/SEI 43.
a) At least ten recorded three-component accelerogram time-histories that are representative of the site seismic hazard, based on consideration of hazard deaggregation, local sources, and site effects, shall be collected. The rationale for record selection shall be documented, including the magnitude, distance, site condition, and other criteria, in relation to the site seismic hazard.
Note: As these representative accelero grams are likely to have been recorded at sites and elevations in the foundation strata that differ from the specific site soil conditions, the accelerogrom records and their corresponding response spectra should be conservatively normalized to a ground surface datum. Strong motion accelero gram records typically include the effects of near surface soil and rock material supporting the recording instruments. Care should be token with records below the 085GM as such effects can become non-linear as ground motion increases,
b) The corresponding response spectra for each of the desired damping levels shall be calculated from the strong motion time-histories. The maximum frequency intervals for calculating spectral values for the response spectra shall be as specified in Table 2.
Note: The vertical-to-horizontal component ratio may be obtained from statistical analysis of the selected
records, before normalization.
c) Each response spectrum may be normalized with respect to its peak ground motion parameters (acceleration, velocity, and displacement) to determine the amplification factor of each frequency relative to each response parameter (acceleration, velocity, and displacement).
d) The mean, standard deviation, and 90th percentile values of the amplification factor of each frequency may be calculated by a statistical analysis of the data obtained In Item c). Note: In general, normalization to peak ground acceleration gives the smallest standard deviation in the high frequency range while, for low frequencies, normalization to peak ground displacement yields the smallest standard deviation. For intermediate frequencies, normalization to peak ground velocity gives a nearly constant standard deviation over the entire frequency range. Therefore, the minimum standard deviation may be used as a criterion to define the limits of the frequency range for scaling by each parameter.
e) Site-specific ground response spectra may be developed by multiplying the applicable DBSGM parameters of peak acceleration, peak velocity, and peak displacement by their amplification factors as specified in Item d), corresponding to the appropriate damping values.CSA N289.3-2020 pdf free download.