Development of Performance Based Tsunami Engineering (PBTE)

1. Development of Performance Based Tsunami Engineering(PBTE) University of Hawaii at Manoa H. Ronald Riggs Ian N. Robertson

2. Source Mechanism Tsunami Generation Open Ocean Propagation Tsunami Modeling Probabilistic Tsunami Hazard Analysis Consequences (Life and economic losses) Warning Systems Social Sciences Public Policy Societal Impact Assessment Tsunami Research Coastal Inundation Performance Levels

3. Source Mechanism Tsunami Generation Open Ocean Propagation Tsunami Modeling Probabilistic Tsunami Hazard Analysis Focus of NEESR Study Ocean, Hydraulic and Structural Engineering Performance Based Tsunami Engineering Consequences (Life and economic losses) Warning Systems Social Sciences Public Policy Societal Impact Assessment Tsunami Research Fluid-Structure Interaction Scour Modeling Structural Loading Structural Response Coastal Inundation Performance Levels

4. Project Team

5. Advisory Panel

6. OSU Wave Tank Facility

7. Technical Areas • Tsunami bore formation, runup, and coastal inundation • Sediment transport and scour • Fluid forces on structures • Structural response, analysis and design

8. Runup Experiments and Modeling • Site-specific bathymetry • Effect of fringing reefs • Surface roughness • Bore formation • Energy dissipation

9. 48.8 m 3.66 m Individual piston–type waveboards runup/reef 1:5 wave propagation 3.66 m runup / reef 1:10 wave propagation 3.66 m runup / reef 1:15 wave propagation 26.5 m Additional separating walls T W B Run-up Experiments • Tsunami wave basin will be modified to allow for three individual flumes with different bottom slopes (July - Dec 2007)

10. resistance wave gauges gap piston ~2m ADVs 1m slopes 1:5 1:15 1:10 ~18.8m ~30m ~20m ~10m Run-up Experiments-Constant Slope • Solitary waves with heights at 0.05m increments up to 0.65m • Study bore formation and energy dissipation • Resistance wave gauges and Acoustic Doppler Velocimeters (ADVs) will capture flow velocity • Benchmark tests for bed roughness, fringing reef, scour and structural loading

11. piston resistance wave gauges absorber h2 ADVs - h2 h1 1:10 1:5 1:15 ~30m ~15m Run-up Experiments-Fringing Reef • Fringing reef will be simulated by curtailing the beach slopes at –h2, water level, and +h2. • Solitary waves with height at 0.05m increments up to 0.65m

12. laser altimeter high speed camera piston absorber Run-up Experiments • Laser altimeter will track free surface when air entrainment distorts resistance gauges and ADV readings. • Particle Imaging Velocimetry (PIV) will monitor transition to white water. • High speed camera will track markers on still water and dry bed.

13. Sediment Transport and Scour • Develop and validate sediment transport mechanisms • Pump up of sediments due to large-scale vortices created by bore collapse. • Entrainment of local sediment by instantaneous bed shear stress. • Enhanced transport due to soil instability (momentary static liquefaction caused by high pore pressure during drawdown)

14. Scour Experiments • Preliminary scour tests in Large Wave Flume (Fall 2006) • Utilize existing sand bed from beach erosion experiment • Velocity measurements using ADVs and PIV • Sediment concentration using Fiber Optic Backscatter (FOBS) • Pore pressures sensors to monitor soil instability

15. laser altimeter piston ~2m 1m 1:10 ~18.8m ~30m ~20m Velocimeter + Fiber Optic Backscatter (FOBS) Pore pressure transducers Sediment Transport Experiments • Repeat 1:10 and 1:15 bottom slope tests with moveable bed • Well-graded sand bed (0.2mm median grain size)

16. laser altimeter piston ~2m 1m 1:10 ~18.8m ~30m ~20m Velocimeter + FOBS Pore pressure transducers Scour Experiments • Include Plexiglas cylinder to simulate pile.

17. Fluid Forces on Structures • Horizontal hydrodynamic loads • Vertical hydrodynamic loads • Debris impact loads • Debris damming loads

18. Fluid-Structure Experiments laser altimeter high speed camera • Utilize fringing reef setup to produce bore. • Monitor loading on structural elements and simple structural systems piston absorber Simple Structure

19. Fluid-Structure Experiments laser altimeter high speed camera • Utilize fringing reef setup to produce bore. • Monitor loading on structural elements and simple structural systems • Monitor debris damming effects piston absorber Shipping Container

20. Fluid-Structure Simulation • Use Reynolds Averaged Navier Stokes, RANS fluid models with the experimental data to improve fluid-structure interaction modeling • Combination of FLUENT + ABAQUS • Possible use of COMSOL (FEMLAB)

21. Structural Response and Design • Structural response to hydraulic and impact loads • Progressive collapse prevention • Prescriptive design • Methodology for site-specific PBTE

22. Maximum Considered Tsunami Tsunami Wave Height Very Rare Events Design Tsunami Rare Events Minor Tsunami Occasional Events Vertical evacuation Collapse Prevention Immediate Occupancy Frequent Events Life safety Building Performance Level Performance Levels

23. Outreach • Princeton REU program (summer 06) • Review of existing design guidelines to protect coastal structures against erosion and scour damage. • Assist with design and setup of scour experiments. • Oregon State University • Web telecast of all experiments performed in the TWB. • Selected experiments will be incorporated into an educational webcast for K-12 audience. • University of Hawaii • Summer 2006 – two High School interns working on preliminary FLUENT modeling • Enhancement of tsunami display at Bishop Museum

24. New Science Adventure Center • Includes tank showing generation of storm and tsunami waves Education and Outreach • Bishop Museum - Honolulu

25. Seismic Tsunami Storm Waves Landslide Tsunami

26. Thank-you!