cena h and v site amplification
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CENA H and V SITE AMPLIFICATION. Walter Silva Pacific Engineering and Analysis October 1, 2009. NGA-E Horizontal Component - Conditional on V S (30m), is Amplification for WNA Similar to CENA Across Loading Levels?. Issues: Similarities in Profiles Velocities - PowerPoint PPT PresentationTRANSCRIPT
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CENA H and V SITE AMPLIFICATION
Walter Silva
Pacific Engineering and Analysis
October 1, 2009
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• NGA-E Horizontal Component
- Conditional on VS(30m), is Amplification for
WNA Similar to CENA Across Loading
Levels?
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• 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
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• 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
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• Nonlinear Dynamic Material Properties- WNA, Peninsular Range Curves- CENA Curves
- Daniel Is, SC- Savannah River, G- Grand Gulf, M- Riverbend, M- ORNL, T- ?
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• 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
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• Site/Region Specific Hazard
– ≈ 35 NPP
– ≈ 100 projects
– DOE Sites
• Savannah River
• ORNL• Paducah
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• 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
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• 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)
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• 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
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• 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
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• 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
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• 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
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• Look at Close Distance V/H Ratios
–WNA Hard Rock
–CENA
»Nahanni
»Gazli
»New Brunswick
»Goodnow
»Monticello
»New Hampshire
»Enola, Arkansas
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– 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
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Profile Comparison
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– 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
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Amplification M1P1
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Amplification M1P1(Cont.)
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Amplification
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Amplification(Cont.)
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Mean Centered NEHRP Profiles
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NEHRP AmplificationCategory C, WUS,
CEUS
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NEHRP AmplificationCategory D, WUS,
CEUS
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NEHRP AmplificationCategory E, WUS, CEUS
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Shear Wave Velocity Profiles
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Shear Wave Velocity Profiles(cont.)
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Profile Categories, Depth Bins, & Classes
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Profile kappa values from small strain damping over maximum
profile mean depth
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Comparison of UHS
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EPRI 28 Nuclear Plant Sites
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PGA 6-Sigma Rock Hazards
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Weight Summary
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Historic and Instrumental Seismicity
for the SEUS
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