2013 EERI Annual Meeting Session: Tsunami Design

1. Performance-based Design
Considerations for Tsunami Vertical
Evacuation Buildings
Presented at 65th EERI Annual Conference
Date: February 14, 2013
Kent Yu – 503.223.9932 / kyu@degenkolb.com
Degenkolb Engineers

2. Overview
 Oregon Tsunami Exposure
 Tsunami Vertical Evacuation Building
 Debris Types
 Performance Objectives
 Design Loads
 Closing Thoughts

3. Cascadia Subduction Zone Earthquake
Oregon is a geologic mirror-image of Northern Japan. In both places, the Pacific Ocean
floor is sliding beneath the adjacent continents along giant faults called subduction
zones. (Graphic by Dan Coe, DOGAMI)

4. Cascadia Subduction Zone Earthquake

5. Oregon Tsunami Exposure
(Source: Nate Wood/2007, USGS)

6. Tsunami Simulation at Cannon Beach
Elevation vs. Time
18
Depth (Location 2)
Depth (Location 4)
15
12
Depth (ft)
9
6
3
0
1000 1500 2000 2500 3000 3500 4000
Time (s)
Velocity vs. Time (+ inland)
15
10
Velocity (ft/s) (+ Inland)
5
0
-5
Velocity (Location 2)
-10
Velocity (Location 4)
-15
1000 1500 2000 2500 3000 3500 4000
Time (s)
(Source: DOGAMI SP 41, 2009) (Source: YouTube, Onagawa Tsuanmi)

7. Oregon Tsunami Vulnerabilities
City of Seaside with 83% of its population, 89% of its
employees and almost 100% its critical facilities in the tsunami
inundation zone (Source: Oregon Resilience Plan)

8. Minamisanriku
High Ground
Residential Residential
Neighborhood Neighborhood
EOC
Hospital
Police HQ
Department
Store
Multi-Family Housing &
Tsunami Vertical Evacuation Building
(Source: Oregon Resilience Plan)

9. MSR: EOC

10. MSR: Hospital

11. Tsunami Evacuation Building

12. Debris and Structural Damage
> NSF Field Team:
Clay Naito (Lehigh U.)
Dan Cox (OSU)
Kent Yu (Degenkolb)
> Tsunami Borne Debris
Wood Debris
Boats/Ships
Vehicles/Cars
Shipping Containers
Building Components

13. Wood Debris
Photo:
Y. Okuda
BRI Japan
Photo: Y. Okuda BRI Japan

14. Vehicle Debris
Ofunato, Japan

15. Boat/Ship Debris

16. Shipping Container Debris
Sendai, Japan

17. Building Component Debris

18. Fuel Storage
Containers

19. Impact Cases

20. Wood Construction
• 4 m Inundation Threshold
(MLITT, Japan)

21. Steel Building

22. Reinforced Concrete Building

23. Lessons Learned: Overturned
Buildings

24. US Tsunami National Standard
> Hawaii Tsunami Code
> FEMA P646 Tsunami Vertical Evacuation Building
(2008, 2012)
> ASCE Tsunami Loading and Effects Committee
Chaired by Gary Chock
> ASCE 7 Chapter 6 to be published in ASCE 7-16
2018

25. Lessons Learned: Evacuation
Structure Tall Enough?
(Source: P646 & Gary Chock, 2012 )

26. Design Performance Objectives
> Performance objective
• Immediate Occupancy for MCE (comparable or better
than hospitals)
• Little Residual deformations after EQ
• Current Code Design (with I =1.5) may not be adequate
(Thomas et al. 2012, 15WCEE)

27. Design Loads
> Dead Loads
Self Wt of Structure (beams, columns, slabs)
Cladding/Partitions
Mechanical/electrical/plumbing
Flooring/Roofing
> Live
Evacuation Zone (100psf)
• Non-Reducible

28. Design Loads
> Seismic Loads
0.6
0.4
Acceleration (g)
0.2
0 In Oxnard from 1994
-0.2 0 10 20 30 40 50 60
Northridge EQ
-0.4
-0.6
Time (sec.)
0.4
N-S Acceleration (g)
0.2
0
0 20 40 60 80 100 120 140 160 180 200
-0.2
-0.4
Time (sec.) In Ica from 2007 Peru
M8 EQ (105 km from
> Structural Verification epicenter)

29. Tsunami Effects
Elevation vs. Time
18
Depth (Location 2)
Depth (Location 4)
15
12
Depth (ft)
9
6
3
0
1000 1500 2000 2500 3000 3500 4000
Time (s)
Velocity vs. Time (+ inland)
15
10
Velocity (ft/s) (+ Inland)
5
0
-5
Velocity (Location 2)
-10
Velocity (Location 4)
-15
1000 1500 2000 2500 3000 3500 4000
Time (s)

30. Design Loads
> Tsunami Loads
 Impulse Load
• Leading edge of wave
 Hydrodynamic Load
• Drag on Columns
 Impact Loads
• Impact of large objects
(log, car, or/and
container)
 Damming Between Columns
Buoyancy Forces

31. Structural Layout Consideration
> Design Vertical Layout to Minimize Tsunami
Loads
> Breakaway Walls
> Prevent Progressive Collapse
> Multiple Line Defense

32. TEB Structural Design
> Foundations
• Scouring Issue
• Piles to provide structural support
• Grade beams to interconnect pile caps
• Slab-on-grade tied to grade beams
(Source: Cannon Beach City Hall White Paper, 2009)

33. Tsunami Vertical Evacuation Refuge
Japan Proposed in Oregon
Japan
Under construction in Thailand
3/4/2013Yumei

34. Lessons Learned: Why People
Don’t Evacuate?

35. Closing Thoughts
> Assess Tsunami hazard accurately
> Develop Tsunami Inundation Maps and Provide
Useful Engineering Parameters Relevant To
Structural Design and Assessment
> Sound Planning based on Response and
Recovery (schools, critical facilities)
> Build Vertical Evacuation Structures as
appropriate
> Education, Training, and Practice