Post-Disaster Structural Data Collection Following the Tohoku Tsunami

Ian N. Robertson

University of Hawaii at Manoa

Post-Disaster Structural Data Collection Following the Tohoku Tsunami

PI: Ian Robertson, University of Hawaii Collaborative PI: Michael Olsen, Oregon State Univ. The objective of this NSF-funded RAPID project was to perform detailed structural and LiDAR surveys of selected structures and surrounding topography for use in future time-history tsunami modeling of inundation and validation of non-linear structural response analysis.

Major Outcomes 1) Validation of NEOWAVE tsunami inundation modeling. 2) Validation of hydrodynamic loading expressions

developed in laboratory experiments. 3) Contribution to development of tsunami design

guidelines for use in future US design codes.

LiDAR Data Collection

• 4 billion points collected for topography and structures

• Topography maps of Sendai, Onagawa and Rikuzentakata

• LiDAR scans of numerous structures available for detailed tsunami loading analysis

Compiled 3-D LiDAR scan of Onagawa, Japan

NEOWAVE Tsunami Simulation

Kwok Fai Cheung and Yoshiki Yamazaki at UH High resolution tsunami modeling from source to

inundation Shock capturing scheme to model wave breaking

and bore formation First Place at international competition at OSU

NEOWAVE Flow Depth - Onagawa

NEOWAVE Flow Velocity - Onagawa

Transect 1 E-W

Transect 2 N-S

Transect 1 E-W

— : u; — : v; — : sqrt(u2+v2)

x = 0m

x = 100m

x = 200m

x = 300m

x = 400m

x = 500m

x = 600m

x = 700m

x = 800m

— : MSL; — : sea level at tsunami arrival (-40cm)

Transect 2 N-S

— : u; — : v; — : sqrt(u2+v2)

x = 0m

x = 150m

x = 300m

x = 450m

x = 600m

x = 750m

x = 900m

x = 1050m

x = 1200m

x = 1350m

— : MSL; — : sea level at tsunami arrival (-40cm)

Select structures or structural elements based on observed damage and likely cause

Determine estimates of flow depth and velocity Complete structural failure only indicates that

loads exceeded the capacity Undamaged buildings show potential for

success, but only indicate that capacity was greater than loads

Particularly interested in near-collapse or partial failure case studies

Case Studies for Evaluation of Tsunami Loads and Effects

Lateral Loading on Walls - Japan

Onagawa reinforced concrete fish storage building

Hydrodynamic lateral load Measure wall dimensions,

reinforcement layout and take samples of rebar and concrete

Onagawa Outflow

Marine Pal Buildings

Concrete Building

• Pressurized by flow stagnation. • Wall reinforcing tested to be JIS G3112 Grade SD 390. • The taller wall rupture occurred when the return flow ≥ 5.5 m/s. • Other shorter walls do not yield and so v < 7.5 m/s.

Steel Building

• Video shows outflow between Marine Pal buildings at 7.5 to 8.5 m/s.

5.5 < v < 7.5 m/s

7.5 < v < 8.5 m/s

Evaluation of Structural Response Steel-framed Building

Onagawa steel framed building near collapse Measure all member sizes and overall dimensions Note damage caused during drawdown – building

leaning towards ocean

Onagawa Built Environment Captured with LiDAR

NSF Rapid grant - funding for LiDAR survey of selected buildings and topography

Surveys directed by Michael Olsen of OSU and Lyle Carden of Martin & Chock

Onagawa Three-Story Steel Building Frame Survival

Three-story steel moment-resisting frame exposed to 8 m/s outflow estimated from video analysis.

At about 67% blockage of the original enclosure (33% open), the return flow is sufficient to yield the top of the second story columns with 30-cm drift of third floor (First story column is stronger section.)

Fully clad building would have collapsed. Loss of cladding reduced the building’s projected area.

LiDAR scan shows final 50-cm third floor drift.

Minami Gamou Wastewater Treatment Plant - subjected to direct bore impact

Minami Gamou STP Video

Sendai - Bore Strike on R/C Structure

Minami Gamou Wastewater Treatment Plant - subjected to direct bore impact

Bore Strike on R/C Structure

Minami Gamou STP

Lidar Scan of deformed shape

Structural drawings obtained from the Wastewater Treatment Plant

Bore Strike on R/C Structure

Minami Gamou Wastewater Treatment Plant

Interior view of 2-story wall Lidar scan of 2-story wall

Solitary Wave Breaking on Submerged Reef Crest

NEESR - Structural Loading Direct Bore Impact on Solid Wall

NEESR – Development of Performance Based Tsunami Engineering, PBTE

NEESR – Development of Performance Based Tsunami Engineering, PBTE

Hydrodynamic Force on Wall due to Bore Impact

Based on conservation of mass and momentum

++= 3

43

1 )(21 22

jjjjbsww vhgvhghF ρ

Wall load expression comparison with experimental data

Velocity Analysis

Video rate of 30 fps Time from Frame 260 to 316 = 1.87 sec. Distance between buildings = 12.2 m Bore velocity = 12.2/1.87 = 6.5 m/s Jump height approx. 5.5m over approx. 0.5m standing water

Bore Impact Forces – Minami Gamou Wastewater Treatment Plant

Comparison with Different Bore Pressures used in Japan Tsunami Standards

++= 3

43

1 )(21 22

jjjjbsww vhgvhghF ρ

hj = 5.5m

ds = 0.5m

hb=hj +ds = 6.0m

vj = 6.5m/s

Bore Impact Forces – Minami Gamou Wastewater Treatment Plant

0

200

400

600

800

1000

1200

1400

1600

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20

Base

She

ar (k

N) (

per u

nit w

idth

of w

all)

Maximum Transverse Wall Displacement (m)

First Yield of Columns at Base of Wall

First Yield at Edge of Wall

First Yield of Beam at Ends of Wall & First Yield at Base of Wall

First Yield at Midheight of Wall

First Yield of Ends of Roof Beams &First Yield at Midspan of Columns

Maximum Force for 3x Hydrostatic Pressure

Maximum Force for OCADI Pressure

Maximum Force for Theoretical Bore Pressure

Minami Gamou Wastewater Treatment Plant - subjected to direct bore impact

FEA compared with Lidar scan

0.0 0.10 (m) 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.0 1.10 1.20 1.30

ASCE 7-10 Minimum Design Loads for Buildings and Other

Structures Minimum Design Loads for Buildings and Other Structures Chap 1 & 2 – General and load combinations Chap 3 - Dead, soil and hydrostatic loads Chap 4 - Live loads Chap 5 - Flood loads (riverine and storm surge) Chap 6 - Vacant Chap 7 - Snow loads Chap 8 - Rain loads Chap 10 - Ice loads Chap 11 – 23 - Seismic Design Chap 26 – 31 - Wind Loads

Proposed ASCE 7-16

Minimum Design Loads for Buildings and Other Structures Chap 1 & 2 – General and load combinations Chap 3 - Dead, soil and hydrostatic loads Chap 4 - Live loads Chap 5 - Flood loads (riverine and storm surge) Chap 6 – Tsunami loads and effects Chap 7 - Snow loads Chap 8 - Rain loads Chap 10 - Ice loads Chap 11 – 23 - Seismic Design Chap 26 – 31 - Wind Loads

ASCE 7 Sub-committee on Tsunami Loads and Effects

Formed in January 2011

16 voting and 12 associate members

Chaired by Gary Chock, S.E., Martin & Chock Inc.

3 meetings per year thus far with draft document now

in development

6.1 General Requirements 6.2 Definitions 6.3 Symbols and Notation 6.4 General Tsunami Design Criteria 6.5 Procedures for Tsunami Hazard Assessment 6.6 Procedures for Tsunami Inundation Analysis 6.7 Design Parameters for Tsunami Flow over Land 6.8 Design Procedure for Tsunami Inundation 6.9 Hydrostatic Loads 6.10 Hydrodynamic Loads 6.11 Impact Loads 6.12 Foundation Design 6.13 Structural countermeasures for reduced loading on buildings 6.14 Special Occupancy Structures 6.15 Designated Nonstructural Systems (Stairs, Life Safety MEP) 6.16 Non-building critical facility structures C6 Commentary and References

Proposed Scope of the ASCE Tsunami Design Provisions 2016 edition of the ASCE 7 Standard, Minimum Design Loads

for Buildings and Other Structures

6.1 General Requirements 6.2 Definitions 6.3 Symbols and Notation 6.4 General Tsunami Design Criteria 6.5 Procedures for Tsunami Hazard Assessment 6.6 Procedures for Tsunami Inundation Analysis 6.7 Design Parameters for Tsunami Flow over Land 6.8 Design Procedure for Tsunami Inundation 6.9 Hydrostatic Loads 6.10 Hydrodynamic Loads 6.11 Impact Loads 6.12 Foundation Design 6.13 Structural countermeasures for reduced loading on buildings 6.14 Special Occupancy Structures 6.15 Designated Nonstructural Systems (Stairs, Life Safety MEP) 6.16 Non-building critical facility structures C6 Commentary and References

Proposed Scope of the ASCE Tsunami Design Provisions 2016 edition of the ASCE 7 Standard, Minimum Design Loads

for Buildings and Other Structures

6.1 General Requirements 6.2 Definitions 6.3 Symbols and Notation 6.4 General Tsunami Design Criteria 6.5 Procedures for Tsunami Hazard Assessment 6.6 Procedures for Tsunami Inundation Analysis 6.7 Design Parameters for Tsunami Flow over Land 6.8 Design Procedure for Tsunami Inundation 6.9 Hydrostatic Loads 6.10 Hydrodynamic Loads 6.11 Impact Loads 6.12 Foundation Design 6.13 Structural countermeasures for reduced loading on buildings 6.14 Special Occupancy Structures 6.15 Designated Nonstructural Systems (Stairs, Life Safety MEP) 6.16 Non-building critical facility structures C6 Commentary and References

Proposed Scope of the ASCE Tsunami Design Provisions 2016 edition of the ASCE 7 Standard, Minimum Design Loads

for Buildings and Other Structures

6.1 General Requirements 6.2 Definitions 6.3 Symbols and Notation 6.4 General Tsunami Design Criteria 6.5 Procedures for Tsunami Hazard Assessment 6.6 Procedures for Tsunami Inundation Analysis 6.7 Design Parameters for Tsunami Flow over Land 6.8 Design Procedure for Tsunami Inundation 6.9 Hydrostatic Loads 6.10 Hydrodynamic Loads 6.11 Impact Loads 6.12 Foundation Design 6.13 Structural countermeasures for reduced loading on buildings 6.14 Special Occupancy Structures 6.15 Designated Nonstructural Systems (Stairs, Life Safety MEP) 6.16 Non-building critical facility structures C6 Commentary and References

Proposed Scope of the ASCE Tsunami Design Provisions 2016 edition of the ASCE 7 Standard, Minimum Design Loads

for Buildings and Other Structures

6.1 General Requirements 6.2 Definitions 6.3 Symbols and Notation 6.4 General Tsunami Design Criteria 6.5 Procedures for Tsunami Hazard Assessment 6.6 Procedures for Tsunami Inundation Analysis 6.7 Design Parameters for Tsunami Flow over Land 6.8 Design Procedure for Tsunami Inundation 6.9 Hydrostatic Loads 6.10 Hydrodynamic Loads 6.11 Impact Loads 6.12 Foundation Design 6.13 Structural countermeasures for reduced loading on buildings 6.14 Special Occupancy Structures 6.15 Designated Nonstructural Systems (Stairs, Life Safety MEP) 6.16 Non-building critical facility structures C6 Commentary and References

Proposed Scope of the ASCE Tsunami Design Provisions 2016 edition of the ASCE 7 Standard, Minimum Design Loads

for Buildings and Other Structures

ASCE 7 Sub-committee on Tsunami Loads and Effects

Committee balloting scheduled for summer 2013, then

transfer to ASCE 7 Main Committee

If adopted, will become Chapter 6 of ASCE 7-16

Will then be referenced by IBC 2018

Arigato Gosai Mas Any Questions?

Tampered sign at Waikaloa Resort, Kona, Hawaii