Nonlinear effects in Earthquake Soil Structure Interaction of Nuclear Power Plants

Transcription

1 Nonlinear effects in Earthquake Soil Structure Interaction of Nuclear Power Plants Feng, Sinha, Abell, Yang, Behbehani, Orbović, McCallen, Jeremić UCD, LBNL, CNSC SMiRT24 Busan, Republic of Korea

2 Outline Introduction Modeling and Simulations Summary

3 Outline Introduction Modeling and Simulations Summary

4 Motivation Motivation Improve seismic modeling and simulation for infrastructure objects Use of high fidelity numerical models to analyze seismic behavior of soil structure nuclear facilities Reduction of modeling uncertainty, ability to perform high(er) level of sophistication modeling and simulation Accurately follow the flow of seismic energy in a soil structure system

5 Outline Introduction Modeling and Simulations Summary

6 Seismic Motions Development of Seismic Motions 1D and/or 2D and or 3 1D and/or 3D (6D) motions can be used 3D motions from regional scale modeling Knowledge of geology (deep and shallow) needed Using SW4 (LLNL): Dr. Rodgers, Dr. Pitarka and Dr. Petersson

7 Seismic Motions Regional Model Motions (Rodgers et al LLNL)

8 Seismic Motions Free Field Verification Ux [m] SW4 model Free Field Uy [m] SW4 model Free Field (a) Relative Displacement Uz [m] SW4 model Free Field SW4 model Free Field SW4 model Free Field SW4 model Free Field Ax [g] 0.0 Ay [g] 0.0 Az [g] (b) Acceleration

9 Seismic Motions Seismic Motions: SW4 to Real ESSI ESSI nodes ESSI Box ( u1, u2, u3,,, ) m 300m 100m Grid spacing ~ 5m 30km 14km 5 km SW42ESSI 72m 72m 56m 36m embedded

10 Inelasticity NPP Model Auxiliary Building Containment Building Damping Layers Center of ESSI Box Foundation Damping Layers Contact Soil DRM Layer

11 Inelasticity Inelastic/Nonlinear Analysis input loading stage increment iteration output

12 Inelasticity Inelastic Soil and Inelastic Contact Shear velocity of soil V s = 500m/s Undrained shear strength (Dickenson 1994) V s [m/s] = 23(S u [kpa]) For V s = 500m/s Undrained Strength S u = 650kPa and Young s Modulus of E = 1.3GPa von Mises, Armstrong Frederick kinematic hardening (S u = 650kPa at γ = 0.01%; h a = 30MPa, c r = 25) Soft contact (concrete-soil), gaping and nonlinear shear e10 Stress σ [kpa] Strain ɛ [%] Stiffness Kn [N/m] Penetration δn [mm]

13 Inelasticity Acc. Response, Top of Containment Building 1 Elastic Inelastic 1 Elastic Inelastic 1 Elastic Inelastic Ax [g] 0 Ay [g] 0 Az [g] Elastic Inelastic Elastic Inelastic Elastic Inelastic FFT Ax [g] Frequency [Hz] FFT Ay [g] Frequency [Hz] FFT Az [g] Frequency [Hz]

14 Inelasticity Acceleration Traces, Free Field g 20 0 C 18 Depth [m] 50 D E F G Width [m] 8

15 Inelasticity Acceleration Traces, Elastic vs Inelastic A 1g B A 1g B C 18 0 C 18 Depth [m] 50 D E Depth [m] 50 D E F G F G Width [m] Width [m] 8

16 Inelasticity Elastic and Inelastic Response: Differences

17 Inelasticity Energy Dissipation in Large-Scale Model (NPP)

18 Outline Introduction Modeling and Simulations Summary

19 Summary US-DOE Project for ESSI of Nuclear Facilities The Real ESSI Simulator System (UCD/LBNL) Modeling from seismic source to NPP (LLNL/UCD/LBNL) High Quality Validation test (UNR/UCD/LBNL)

20 Summary Summary Reduction of demand due to inelastic effects The Real ESSI Simulator system used for all the model development, modeling/simulations and post-processing The Real ESSI Simulator system documentation and information about different availability/use options is at Nonlinear/Inelastic Earthquake Soil Structure Interaction (ESSI) short course offered this fall in San Francisco, more info at Funding from and collaboration with the US-DOE, US-NRC, US-NSF, CNSC-CCSN, UN-IAEA, and Shimizu Corp. is greatly appreciated,