ML090960684
| ML090960684 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 03/26/2009 |
| From: | Litehiser J, Mcguire R, Ostadan F Bechtel Corp, Florida Power & Light Co, Risk Engineering |
| To: | Office of New Reactors |
| Nguyen C NRO/DNRL 301-415-1177 | |
| References | |
| Download: ML090960684 (72) | |
Text
SEISMIC CHARACTERIZATION March 26, 2009 Joe Litehiser - Bechtel Corporation Farhang Ostadan - Bechtel Corporation Robin McGuire - Risk Engineering Inc.
2 The information provided in the following presentation is of a preliminary nature and is considered DRAFT
3 Earthquake Catalog Seismic Sources
- EPRI-SOG Sources
- Modifications of EPRI-SOG Sources
- New Caribbean Sources Attenuation Models for New Caribbean Sources Probabilistic Seismic Hazard Analysis Soil Column, Amp. Factors & Site Response Ground Motion Response Spectra (GMRS)
Foundation Input Response Spectra (FIRS)
Topics
4 Development of Seismicity Catalog in Two Phases Basis for Phase 1 Earthquake Catalog Update [NRC Guidance (1.208)]
- The EPRI-SOG seismic source model, including the seismicity catalog, is an acceptable starting point for the sites in the central and eastern United States (CEUS).
- To evaluate the adequacy of the EPRI-SOG source model in the light of more recent data.
Purpose for Phase 2 Earthquake Catalog To define earthquakes to help characterize potentially important seismic sources in the Caribbean.
Earthquake Catalog
5 Phase 1 Earthquake Seismicity:
Update and supplement EPRI catalog for region within lat-lon window of 22° to 35° N, 100° to 65° W; for all time through mid-February 2008; considering 34 regional catalogs.
Phase 2 Earthquake Seismicity:
Supplement Phase 1 catalog with Caribbean seismicity within lat-lon window of 15° to 24° N, 100° to 65° W; for all time through mid-March 2008; considering 23 regional/global catalogs.
Earthquake Catalog
6 Creating a New Earthquake Catalog (Phase 1 & 2)
Compile the individual catalogs into the same format.
Sort chronologically, and compare the catalogs by considering the catalog preference order.
Remove duplicate events.
Convert magnitudes to Emb [Phase1] and Mw [Phase 2].
Remove aftershocks and foreshocks.
Earthquake Catalog
7 Earthquake Catalog
8 Supplemental Areas of Incompleteness Regions Gulf of Mexico Near Florida Near Atlantic Southern Boundary of EPRI Incompleteness Regions 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 3
3 2
2 2
3 3 3 3 3
3 3 3
3 2
2 2
2 2
2 2
2 2 3 3
3 3
2 3
Extent of original and supplemental EPRI-SOG sources in the Gulf of Mexico and around Florida required probability of detection matrices for three new areas.
Probability of detection for a given magnitude and time window is expected to be less offshore.
9
- Original EPRI source zones
- Update of EPRI source model
- Updated Charleston Seismic Source (UCSS) model -
SSHAC Level 2
- New Caribbean source model - SSHAC Level 2 Turkey Point Site Seismic Sources
10
- Turkey Point site not part of the original EPRI study
- Turkey Point site region extends beyond limits of original EPRI
- New information requires update to EPRI model
- Total of 7 EPRI source zones within 200 mi site region, 5 of which characterize Gulf Coast crust Evaluating EPRI Site Region Source Zones
11 Woodward-Clyde only source that extends south of 25ºN latitude Evaluating EPRI Site Region Earth Science Teams (ESTs) Source Zones
12 Evaluating EPRI Site Region Source Zones
13 Site Region Supplemental Zone - Bechtel
All sources truncated at northern boundary of new Caribbean source model
(~Nortecubana fault) to avoid double counting
14 Site Region Supplemental Zone - Dames & Moore
All sources truncated at northern boundary of new Caribbean source model
(~Nortecubana fault) to avoid double counting
15 Site Region Supplemental Zone - Law Engineering
All sources truncated at northern boundary of new Caribbean source model
(~Nortecubana fault) to avoid double counting
16 Site Region Supplemental Zone - Rondout Associates
All sources truncated at northern boundary of new Caribbean source model
(~Nortecubana fault) to avoid double counting
17 Site Region Supplemental Zone - Weston Geophysical
All sources truncated at northern boundary of new Caribbean source model
(~Nortecubana fault) to avoid double counting
18 Site Region Supplemental Zone - Woodward-Clyde
All sources truncated at northern boundary of new Caribbean source model
(~Nortecubana fault) to avoid double counting
19 Summary of Supplemental Zones & Truncated Woodward-Clyde Zone 1 Area calculated using North America Albers equal area conic projection.
2 From updated seismicity catalog.
3 Not a supplemental zone; Woodward-Clyde source BG-35 geometry is truncated by the northern boundary of new Caribbean seismic source model.
20 Updated Charleston Seismic Source (UCSS)
Model Sources - SSHAC Level 2
21 Updated Charleston Seismic Source (UCSS) Logic Tree with Weights for Each Branch
22 Tectonic Features and Significant Earthquakes of Cuba and the Northern Caribbean
23 Seismicity in the Cuba and Northern Caribbean Region, 1500 to 2008
24 New Caribbean Model - SSHAC Level 2
25 New Caribbean Sources - Summary
26 Turkey Point Seismic Source Zones - Summary Updated Mmax distributions and weights for original EPRI Earth Science Teams (ESTs), except Woodward-Clyde Truncated Woodward-Clyde source BG-35 (Turkey Point Background) at northern boundary of the new Caribbean seismic source model to avoid double counting seismicity in northern Cuba Included 5 new supplemental source zones (one for each EST except Woodward-Clyde) within the site region to characterize areas devoid of source zones in the original EPRI model Charleston seismic source model from the Vogtle ESP application New Caribbean seismic source model
27 Attenuation Models Attenuation Models for EPRI-SOG and near-EPRI-SOG Sources
- EPRI (2004)
Attenuation Models for New Caribbean Sources
- Stochastic ground motion simulation program (Boore, 2005) using empirically determined regional attenuation and source parameters from Motazedian and Atkinson (2005)
28 Attenuation Models for New Caribbean Sources Seismic sources for the Caribbean region in the PSHA require applicable ground motion attenuation models.
Although the Caribbean region is relatively active seismically, the lack of a large dataset of empirical strong ground motion recordings, especially for larger magnitude earthquakes, has prevented the development of an empirical ground motion attenuation relationship for the region.
Motazedian and Atkinson (2005) have analyzed a dataset of approximately 300 earthquakes recorded by stations in Puerto Rico to develop a set of regional attenuation and source parameters. As this dataset spans the magnitude range of 3 - 5.5, it cannot be used directly to develop an empirical attenuation model for earthquakes with magnitudes as large as magnitude 8+, as is needed in the Turkey Point Site PSHA.
29 Attenuation Models for New Caribbean Sources 2.8 g/cm3 2.8 g/cm3 Density 3.6 km/sec 3.6 km/sec Shear Wave Velocity (Vs) at the Source 0.006 sec (EPRI, 1993) 0.03 sec Kappa Chen and Atkinson (2002) CEUS Hard Rock Puerto Rico specific for soft rock site (NEHRP C) conditions based on H/V ratio Site Amplification Atkinson and Boore (1995) Model with hinge points at 75 and 100 km Atkinson and Boore (1995) Model with hinge points at 75 and 100 km Path Duration 241 f 0.59 (Low Case) 359 f 0.59 (Base Case) 536 f 0.59 (High Case) 359 f 0.59 Quality Factor (Q) Model 1/R for R<75km 1.0 for 75<R<100km 1/SQRT(R) for R>100km 1/R for R<75km 1.0 for 75<R<100km 1/SQRT(R) for R>100km Geometrical Spreading 65 bars (Low Case) 130 bars (Base Case) 260 bars (High Case) 130 bars Stress Parameter Simulation Values MA 2005 Values Parameter Regional attenuation and source parameters estimated in the Motazedian and Atkinson (2005) study and values used for the simulation of ground motions
30 Attenuation Models for New Caribbean Sources Simulations are developed for the three source models:
Single Corner Constant Stress Parameter Scaling (referred to as 1CC)
Single Corner Variable Stress Parameter Scaling (referred to as 1CV)
Double Corner (referred to as 2C) and the three stress drop parameter values (ln= 0.7, EPRI 1993):
Low stress parameter value = 65 bars Base stress parameter value = 130 bars High stress parameter value = 260 bars and the three Q model values (ln=0.4, Silva et al. 2003):
Low Qo value = 241 Base Qo value = 359 High Qo value = 536
31 Attenuation Models for New Caribbean Sources SMSIM (Boore, 2005) Point Source Modeling Single Corner Constant Stress Drop Source Model [1CC]
Single Corner Variable Stress Drop Source Model [1CV]
Double Corner Source Model [2C]
Motazedian and Atkinson (2005) regional parameters Atkinson and Chen (2002) CEUS Hard Rock Site Amplification Factors CEUS Hard Rock kappa = 0.006 sec (EPRI, 1993)
Epistemic Variation in Stress Parameter and Q Model PGA, 25, 10, 5, 2.5, 1, and 0.5 Hz Frequency Independent Sigma = 0.645 (Ln units)
(Motazedian and Atkinson, 2005)
32 Attenuation Models for New Caribbean Sources Three Source Spectra Models (1CC, 1CV, 2C)
Mw = 4.75 to 8.75 with step size mag = 0.25 (17 total magnitudes)
Distances = 150 to 2,000 km with equal log spacing for 17 distance steps CEUS Hard Rock Conditions Stress Parameters = 65, 130, and 260 bars Qo Model = 241, 359, and 536 Linear regression model Ln(Y) = C1 + C2*M + (C3 + C4*M)*Ln(R) + C6*(M-6.0)2 + (C7 + C8*M)*R
33 Attenuation Models for New Caribbean Sources Caribbean Attenuation Models: T=0.04sec, M7 0.000001 0.00001 0.0001 0.001 0.01 0.1 100 1000 10000 Distance (km)
SA (g) 1CC-QBase-SDLow 1CC-QBase-SDBase 1CC-QBase-SDHigh 1CV-QBase-SDBase 1CV-QBase-SDHigh 1CV-QBase-SDLow 1CC-QHigh-SDLow 1CC-QHigh-SDBase 1CC-QHigh-SDHigh 1CV-QHigh-SDBase 1CV-QHigh-SDHigh 1CV-QHigh-SDLow 1CC-QLow-SDLow 1CC-QLow-SDBase 1CC-QLow-SDHigh 1CV-QLow-SDBase 1CV-QLow-SDHigh 1CV-QLow-SDLow 1CC-QBase-SDAll 1CC-QHigh-SDAll 1CC-QLow-SDAll 1CV-QBase-SDAll 1CV-QHigh-SDAll 1CV-QLow-SDAll 2C-QBase 2C-QHigh 2C-QLow Caribbean Attenuation Models: T=1.00sec, M7 0.000001 0.00001 0.0001 0.001 0.01 0.1 100 1000 10000 Distance (km)
SA (g) 1CC-QBase-SDLow 1CC-QBase-SDBase 1CC-QBase-SDHigh 1CV-QBase-SDBase 1CV-QBase-SDHigh 1CV-QBase-SDLow 1CC-QHigh-SDLow 1CC-QHigh-SDBase 1CC-QHigh-SDHigh 1CV-QHigh-SDBase 1CV-QHigh-SDHigh 1CV-QHigh-SDLow 1CC-QLow-SDLow 1CC-QLow-SDBase 1CC-QLow-SDHigh 1CV-QLow-SDBase 1CV-QLow-SDHigh 1CV-QLow-SDLow 1CC-QBase-SDAll 1CC-QHigh-SDAll 1CC-QLow-SDAll 1CV-QBase-SDAll 1CV-QHigh-SDAll 1CV-QLow-SDAll 2C-QBase 2C-QHigh 2C-QLow Mw7, 25Hz Mw7, 1Hz
34 Attenuation Models for New Caribbean Sources Caribbean Attenuation Models: Spectra, M7, R150km 0.001 0.01 0.1 1
0.01 0.1 1
10 Period (sec)
Spectral Acceleration (g) 1CC-QBase-SDAll 1CC-QHigh-SDAll 1CC-QLow-SDAll 1CV-QBase-SDAll 1CV-QHigh-SDAll 1CV-QLow-SDAll 2C-QBase 2C-QHigh 2C-QLow Caribbean Attenuation Models: Spectra, M7, R1447km 0.00001 0.0001 0.001 0.01 0.01 0.1 1
10 Period (sec)
Spectral Acceleration (g) 1CC-QBase-SDAll 1CC-QHigh-SDAll 1CC-QLow-SDAll 1CV-QBase-SDAll 1CV-QHigh-SDAll 1CV-QLow-SDAll 2C-QBase 2C-QHigh 2C-QLow Mw7, 150km Mw7, 1447km
35 Attenuation Models for New Caribbean Sources Weights for each of the nine recommended models 0.1666 2C, Q Low 0.1667 2C, Q High 0.1667 2C, Q Base 0.0833 1CV, Q Low 0.0833 1CV, Q High 0.0834 1CV, Q Base 0.0833 1CC, Q Low 0.0833 1CC, Q High 0.0834 1CC, Q Base Model Weight Attenuation Model EPRI (2004) had near equal weighting between 1C and 2C models, so similar weighting considered for Caribbean attenuation model.
36 Attenuation Models for New Caribbean Sources Summary Point Source Ground Motions Regional Attenuation Parameters from Motazedian and Atkinson (2005) study Nine Recommended Attenuation Models Assigned Sigma = 0.645 from MA2005 study
37 Probabilistic Seismic Hazard Analysis Results Rock hazard curves and Uniform Hazard Response Spectra (UHRS)
Deaggregation Smooth rock spectra for site response Site UHRS and GMRS
38 Peak Ground Acceleration (PGA) rock hazard curves PGA Rock Seismic Hazard Curves - Base Calculation 1E-7 1E-6 1E-5 1E-4 1E-3 1E-2 0.001 0.01 0.1 1.
10.
PGA amplitude, g Annual frequency of exceedence 95th Fractile 84th Fractile Mean Median 16th Fractile 5th Fractile
39 10 Hz rock hazard curves 10 Hz Rock Seismic Hazard Curves - Base Calculation 1E-7 1E-6 1E-5 1E-4 1E-3 1E-2 0.001 0.01 0.1 1.
10.
10 Hz Spectral amplitude, g Annual frequency of exceedence 95th Fractile 84th Fractile Mean Median 16th Fractile 5th Fractile
40 1 Hz rock hazard curves 1 Hz Rock Seismic Hazard Curves - Base Calculation 1E-7 1E-6 1E-5 1E-4 1E-3 1E-2 0.001 0.01 0.1 1.
1 Hz Spectral amplitude, g Annual frequency of exceedence 95th Fractile 84th Fractile Mean Median 16th Fractile 5th Fractile
41 Rock UHRS 0.01 0.1 1.
0.1 1
10 100 Spectral acceleration, g Frequency, Hz Rock UHRS for 10-4, 10-5, and 10-6, Mean and Median 10-6 Mean 10-6 Median 10-5 Mean 10-5 Median 10-4 Mean 10-4 Median
42 M-R-deaggregation plots, LF, 10-4
43 M-R-deaggregation plots, HF, 10-4
44 M-R-deaggregation plots, LF, 10-5
45 M-R-deaggregation plots, HF, 10-5
46 Deaggregation M and R values Overall hazard Hazard from R>100 km Struct.
frequency Annual Freq.
Exceed.
M R, km M
R, km 1 & 2.5 Hz 1E-4 7.1 400 7.3 570 5 & 10 Hz 1E-4 5.9 110 6.5 290 1 & 2.5 Hz 1E-5 6.7 190 7.2 560 5 & 10 Hz 1E-5 5.5 31 6.7 250 1 & 2.5 Hz 1E-6 6.3 61 7.2 600 5 & 10 Hz 1E-6 5.5 17 6.9 180
47 10-4 HF and LF rock spectra 0.001 0.01 0.1 0.1 1
10 100 Spectral acceleration, g Frequency, Hz 10-4 spectra High Frequency Low Frequency UHS
48 10-5 HF and LF rock spectra 0.001 0.01 0.1 0.1 1
10 100 Spectral acceleration, g Frequency, Hz 10-5 spectra High Frequency Low Frequency UHS
49 Site Response Soil Column Amplification Factors Site Response
50 Site Response Site specific geotechnical data were used to develop the dynamic soil profiles in the upper 611 ft For deeper layers (12,000 ft), 8 regional sonic logs were used RCTS data were used for the Tamiami sands Damping for the deep soil layers are obtained from the estimate of the total kappa The input motion was specified at the horizon with Vs of 9200 ft/sec 60 randomized profiles were developed for the site profile of each unit
51 Site Response 0
2000 4000 6000 8000 10000 12000 0
2000 4000 6000 8000 10000 12000 Shear Wave Velocity, Vs [ft/sec]
Depth [ft]
0 2000 4000 6000 8000 10000 12000 0
2000 4000 6000 8000 10000 12000 Shear Wave Velocity, Vs [ft/sec]
Depth [ft]
84% Vs Median Vs 16% Vs
52 Site Response
53 Site Amplification 0
2000 4000 6000 8000 10000 12000 0.0 1.0 2.0 3.0 4.0 5.0 6.0 Damping Ratio [%]
Depth [ft]
HF 1E-4 LF 1E-4 HF 1E-5 LF 1E-5 Low-Strain 0
2000 4000 6000 8000 10000 12000 0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.040 0.045 Strain [%]
Depth [ft]
HF 1E-4 LF 1E-4 HF 1E-5 LF 1E-5
54 Site Amplification - GMRS (El -35) 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 0.1 1
10 100 Frequency [Hz]
ARS Amplification 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 0.1 1
10 100 Frequency [Hz]
ARS Amplification 1E-4 LF Input Motion 1E-4 HF Input Motion
55 Horizontal and Vertical Ground Motion Response Spectra (GMRS)
- NUREG/CR-6728, Method 2A
- Apply LF amp factors to smooth input LF rock spectrum
- Apply HF amp factors to smooth input HF rock spectrum
- Envelope the resulting LF and HF soil spectra to get UHRS
56 Input Rock and Preliminary Unsmoothed Soil Response Spectra for Turkey Point 0.01 0.1 1
0.1 1
10 100 Frequency, Hz Spectral acceleration, g 1E-5 rock 1E-5 soil 1E-4 rock 1E-4 soil
57 Reg. Guide 1.208: GMRS
- Smooth the soil spectra [simple 5-point average]
- Section 5. Performance-Based Site-Specific Earthquake Ground Motion Procedure AR
= {mean 10-5 UHRS} ÷ {mean 10-4 UHRS}
= maximum { 1.0, 0.6(AR)0.8 }
= DF {mean 10-4 UHRS},
if AR 4.2
= 45% of {mean 10-5 UHRS},
if AR > 4.2
58 Smoothed Horizontal 1E-4 and 1E-5 Site Spectra and GMRS 0.01 0.1 1
0.1 1
10 100 Spectral acceleration, g Frequency, Hz 1E-5 smooth spectrum GMRS 1E-4 smooth spectrum
59 Smoothed Vertical 1E-4 and 1E-5 Site Spectra and GMRS
60 FIRS Same methodology used for GMRS is used for FIRS FIRS is at the depth of 41.5 ft below finished grade level Two site conditions: Near nuclear island (NI) and far field (FAR) are modeled For NI profile, backfill and lean concrete are considered to the depth of 60.5 ft below finished grade level Results of soil amplifications from the two profiles are enveloped
61 FIRS 0
2000 4000 6000 8000 10000 12000 0
2000 4000 6000 8000 10000 12000 Shear-Wave Velocity [ft/sec]
Depth [ft]
Randomized Randomized Median Input Median 0
2000 4000 6000 8000 10000 12000 0
2000 4000 6000 8000 10000 12000 Shear-Wave Velocity [ft/sec]
Depth [ft]
Randomized Randomized Median Input Median NI Profile FAR Profile
62 FIRS 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 0.1 1
10 100 Frequency [Hz]
ARS Amplification HF - 1E-4 LF - 1E-4 HF - 1E-5 LF - 1E-5 NI Profile 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 0.1 1
10 100 Frequency [Hz]
ARS Amplification HF - 1E-4 LF - 1E-4 HF - 1E-5 LF - 1E-5 FAR Profile
63 Ground Surface Ground Surface - NI Ground Surface - FAR 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0.1 1
10 100 Frequency [Hz]
ARS Amplification HF - 1E-4 LF - 1E-4 HF - 1E-5 LF - 1E-5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0.1 1
10 100 Frequency [Hz]
ARS Amplification HF - 1E-4 LF - 1E-4 HF - 1E-5 LF - 1E-5
64 FIRS FIRS - NI FIRS - FAR 0
0.05 0.1 0.15 0.2 0.25 0.1 1
10 100 Frequency, Hz Spectral acceleration, g 1E-5 smooth spectrum DRS: NI 1E-4 smooth spectrum 0
0.05 0.1 0.15 0.2 0.25 0.1 1
10 100 Frequency, Hz Spectral acceleration, g 1E-5 smooth spectrum DRS: FAR 1E-4 smooth spectrum
65 FIRS 0
0.02 0.04 0.06 0.08 0.1 0.12 0.1 1
10 100 Frequency, Hz Spectral acceleration, g Horizontal FIRS Vertical FIRS
66 SSI Soil Profile 0
100 200 300 400 500 600 700 800 900 1000 0
1000 2000 3000 4000 5000 6000 7000 8000 Vs [fps]
Depth [ft]
Best Estimate (BE)
Lower Bound (LB)
Upper Bound (UB) 0 100 200 300 400 500 600 700 800 900 1000 0.0 1.0 2.0 3.0 4.0 5.0 6.0 Damping [%]
Depth [ft]
Best Estimate (BE)
Lower Bound (LB)
Upper Bound (UB)
NI Profile-Upper 1000 ft
67 SSI Input Motion A set of 3-component acceleration time histories were developed to match horizontal and vertical FIRS (H1, H2, Vertical)
Time history generation follows NUREG0800 SSI input motion were checked at the ground surface level (ADAMS Accession Numbers ML083580072 and ML083020171)
68 SSI Input Motion FPL: FIRS, Horizontal 1 0.001 0.01 0.1 1
0.1 1
10 100 Frequency (Hz)
Spectral Acceleration (g)
Target Spectrum*1.30 Target Spectrum Target Spectrum/1.10 Spectral-matched Time History Final run scaled 1.020 0
FPL: FIRS, Horizontal 2 0.001 0.01 0.1 1
0.1 1
10 100 Frequency (Hz)
Spectral Acceleration (g)
Target Spectrum*1.30 Target Spectrum Target Spectrum/1.10 Spectral-matched Time History Final run scaled 1.022 0
FPL: FIRS, Vertical 0.001 0.01 0.1 1
0.1 1
10 100 Frequency (Hz)
Spectral Acceleration (g)
Target Spectrum*1.30 Target Spectrum Target Spectrum/1.10 Spectral-matched Time History Final run scaled 1.010 0
69 SSI Input Motion - H1 0.
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.1 1
10 100 Frequency [Hz]
Spectral acceleration [g]
0 0.25 0.5 0.75 1
1.25 Ratio DRS/Envelope Horizontal DRS:
Surface Case: LB Case: BE Case: UB ARS Envelope Ratio DRS / Env NI Profile
70 SSI Input Motion - H2 NI Profile 0.
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.1 1
10 100 Frequency [Hz]
Spectral acceleration [g]
0 0.25 0.5 0.75 1
1.25 Ratio DRS/Envelope Horizontal DRS:
Surface Case: LB Case: BE Case: UB ARS Envelope Ratio DRS / Env
71 SSI Input Motion - VT NI Profile 0.
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.1 1
10 100 Frequency [Hz]
Spectral acceleration [g]
0 0.3 0.6 0.9 1.2 1.5 Ratio DRS/Envelope Vertical DRS:
Surface Case: LB Case: BE Case: UB ARS Envelope Ratio DRS / Env 0.
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.1 1
10 100 Frequency [Hz]
Spectral acceleration [g]
0 0.35 0.7 1.05 1.4 1.75 Ratio DRS/Envelope Vertical FIRS: Original Target Adjusted Vertical Target Ratio DRS / Env - NI Ratio DRS / Env - FAR Adjustment Ratio
72 SSI Input Motion - Summary The same check was made for the FAR profile.
The horizontal time histories were uniformly increased by 19%
For vertical motion, the spectra was adjusted and new time history was developed matching the adjusted response spectrum The final check was made for the FAR and NI soil profiles to ensure surface DRS is enveloped Adjusted time histories are recommended for SSI