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
Outline Introduction Modeling and Simulations Summary
Outline Introduction Modeling and Simulations Summary
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
Outline Introduction Modeling and Simulations Summary
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
Seismic Motions Regional Model Motions (Rodgers et al LLNL)
Seismic Motions Free Field Verification Ux [m] 0.2 0.1 0.0 0.1 SW4 model Free Field 0.2 0 10 20 30 40 Uy [m] 0.2 0.1 0.0 0.1 SW4 model Free Field 0.2 0 10 20 30 40 (a) Relative Displacement Uz [m] 0.2 0.1 0.0 0.1 SW4 model Free Field 0.2 0 10 20 30 40 SW4 model Free Field SW4 model Free Field SW4 model Free Field 0.5 0.5 0.5 Ax [g] 0.0 Ay [g] 0.0 Az [g] 0.0 0.5 0.5 0.5 0 10 20 30 40 0 10 20 30 40 0 10 20 30 40 (b) Acceleration
Seismic Motions Seismic Motions: SW4 to Real ESSI ESSI nodes ESSI Box ( u1, u2, u3,,, ) 1 2 3 300m 300m 100m Grid spacing ~ 5m 30km 14km 5 km SW42ESSI 72m 72m 56m 36m embedded
Inelasticity NPP Model Auxiliary Building Containment Building Damping Layers Center of ESSI Box Foundation Damping Layers Contact Soil DRM Layer
Inelasticity Inelastic/Nonlinear Analysis input loading stage increment iteration output
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]) 0.475 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 1000 2 1e10 Stress σ [kpa] 500 0 500 1000 20 10 0 10 20 Strain ɛ [%] Stiffness Kn [N/m] 1 0 0.0 0.5 1.0 Penetration δn [mm]
Inelasticity Acc. Response, Top of Containment Building 1 Elastic Inelastic 1 Elastic Inelastic 1 Elastic Inelastic Ax [g] 0 Ay [g] 0 Az [g] 0 1 0 10 20 30 40 0.10 Elastic Inelastic 1 0 10 20 30 40 0.10 Elastic Inelastic 1 0 10 20 30 40 0.10 Elastic Inelastic FFT Ax [g] 0.05 0.00 0 5 10 15 20 Frequency [Hz] FFT Ay [g] 0.05 0.00 0 5 10 15 20 Frequency [Hz] FFT Az [g] 0.05 0.00 0 5 10 15 20 Frequency [Hz]
Inelasticity Acceleration Traces, Free Field 100 24 22 50 1g 20 0 C 18 Depth [m] 50 D E 16 14 100 F G 12 10 150 150 100 50 0 50 100 150 Width [m] 8
Inelasticity Acceleration Traces, Elastic vs Inelastic 100 50 A 1g B 24 22 20 100 50 A 1g B 24 22 20 0 C 18 0 C 18 Depth [m] 50 D E 16 14 Depth [m] 50 D E 16 14 100 F G 12 100 F G 12 10 10 150 150 100 50 0 50 100 150 Width [m] 8 150 150 100 50 0 50 100 150 Width [m] 8
Inelasticity Elastic and Inelastic Response: Differences
Inelasticity Energy Dissipation in Large-Scale Model (NPP)
Outline Introduction Modeling and Simulations Summary
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)
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 http://real-essi.info Nonlinear/Inelastic Earthquake Soil Structure Interaction (ESSI) short course offered this fall in San Francisco, more info at http://real-essi.info Funding from and collaboration with the US-DOE, US-NRC, US-NSF, CNSC-CCSN, UN-IAEA, and Shimizu Corp. is greatly appreciated,