1 / 41

Comparative Site Amplification Analysis: CENA vs WNA Across Varying Soil Conditions

This study examines the site amplification effects of Conditional on VS(30m) for Central and Eastern North America (CENA) and Western North America (WNA) using shear wave velocities and damping metrics. Key findings show similarities in profiles, velocities, and amplification levels across various loading conditions and soil depths. Notably, CENA exhibits significant differences in kappa values and response characteristics, particularly at shallow soil levels. This research provides essential insights for seismic hazard assessments across multiple DOE sites, including Savannah River and ORNL.

spencer
Télécharger la présentation

Comparative Site Amplification Analysis: CENA vs WNA Across Varying Soil Conditions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CENA H and V SITE AMPLIFICATION Walter Silva Pacific Engineering and Analysis October 1, 2009

  2. NGA-E Horizontal Component - Conditional on VS(30m), is Amplification for WNA Similar to CENA Across Loading Levels?

  3. Issues: Similarities in • Profiles • Velocities • VS (30m) ≈ 180m/sec to 2,000m/sec • Basement VS • WNA ≈ 3,000 ft/sec • CENA ≈ 6,000 ft/sec • CENA Reference ≈ 9,300 ft/sec • Impact Shallow Profiles ≤ 500 ft • Impact Depth to 1 km/sec

  4. Damping (kappa) • WNA, 0.04 sec, 5 Hz Peak • Large Contribution of Bedrock ≈ 0.04 sec • Total kappa Varies Little With Soil Depth • CENA 0.04 SEC, 5 Hz peak Deep Profile > 3,000 ft • Bedrock 0.006 sec, 1,000 ft Soil 0.01 sec • Large Impact on Shallow Profiles at Low Loading Levels

  5. Nonlinear Dynamic Material Properties - WNA, Peninsular Range Curves - CENA Curves - Daniel Is, SC - Savannah River, G - Grand Gulf, M - Riverbend, M - ORNL, T - ?

  6. Differences in Control Motion - Bedrock Kappa - WNA 0.04 sec, 5 Hz - CENA - Precambrian 0.006 sec, 20 Hz - Sedimentary 0.02 to 0.04 sec, 10 Hz to 5 Hz - Relatively Higher Loading at High Frequency, Conditional on PGA

  7. Site/Region Specific Hazard • ≈ 35 NPP • ≈ 100 projects • DOE Sites • Savannah River • ORNL • Paducah

  8. Project Areas • New Jersey, Virginia, Carolinas, Georgia, Tennessee, Indiana, Missouri, Oklahoma • Project Regions • Central US, NYC, South Carolina • Profiles Sampled • Soft to Firm Soil Overlying Hard and Soft Rock • Soil Depths 20 ft to 10,000 ft • Soft to Firm Rock • Several Hundred Feet to Thousands of Feet Over Hard Rock • Profile Database • Several Hundred CENA Profiles

  9. Available Analyses Suggest Deep Soil Response WNA ≈ CENA Across Loading Level - Relatively straightforward - Check/Confirm with Specific Cases • Savannah River - Very Stiff Soil - Over Hard Rock (Crystalline) - Over Soft Rock (Dumbarton Basin)

  10. Southern Coastal Plain - Charleston - Cooper Marl • Piedmont - Residual Soil Saprolite • Southern Miss Embayment • Uplands, Grand Gulf - Till - Deep Stiff Soil • Lowlands, Riverbend - Deep Soft Soil

  11. Issues to Resolve • Shallow Soil < 3,000 ft • Appropriate Total Kappa Constraint • Affects Low Loading Levels • Soft - Firm Rock Over Hard Rock • ≤ 1 km Rock • Appropriate Profile • Appropriate kappa • Piedmont, Saprolite • ≥ 1 km Rock • Characteristics of WNA Soft/Firm Rock

  12. Data Requirements: • Relative Site Response • Kappa Inversions • Shallow Soil (< 3,000 ft) • Soft Rock • Shear-wave Velocities • Recording Sites, at a Minimum VS(30m) • Reference Site and Shallow Soil Sites • > VS to at Least 100m

  13. Verticals • Hard Rock H only or H, V GMPEs • Issues • Need CENA Relative Site Response For V • Empirical CENA H/V Ratios • Small Magnitude/Large Distance • Rock: 1.1 at 1 Hz, 1.5 at 10 Hz • Soil 1.5 at 1 Hz, 1.7 at 5 Hz

  14. Look at Close Distance V/H Ratios • WNA Hard Rock • CENA • Nahanni • Gazli • New Brunswick • Goodnow • Monticello • New Hampshire • Enola, Arkansas

  15. V Site Response Analysis • Incident Inclined P-SV • Nonlinear Constrained Modulus • Uncoupled H and V Components? • NGAE Specifies H Hard Rock Only • Develop Site Specific H Hazard • Develop Site Specific Fully Probabilistic V Hazard • Distribution of V/H Ratios • Duke • Grand Gulf

  16. Profile Comparison

  17. Site Response Analysis • Incident Inclined P-SV • Nonlinear Constrained Modulus • Uncoupled H and V? • NGAE H Hard Rock Only • Develop Site Specific H Hazard • Develop Specific Fully • Probabilistic V Hazard • Distribution V/H Ratios • Duke • Grand Gulf

  18. Amplification M1P1

  19. Amplification M1P1(Cont.)

  20. Amplification

  21. Amplification(Cont.)

  22. Mean Centered NEHRPProfiles

  23. NEHRP AmplificationCategory C, WUS, CEUS

  24. NEHRP AmplificationCategory D, WUS, CEUS

  25. NEHRP AmplificationCategory E, WUS, CEUS

  26. Shear Wave Velocity Profiles

  27. Shear Wave Velocity Profiles(cont.)

  28. Profile Categories, Depth Bins, & Classes

  29. Profile kappa values from small strain damping over maximum profile mean depth

  30. Comparison of UHS

  31. EPRI 28 Nuclear Plant Sites

  32. PGA 6-Sigma Rock Hazards

  33. Weight Summary

  34. Historic and Instrumental Seismicity for the SEUS

More Related