Sapienza naito-25-06-13

Sapienza Universita di Roma 6/27/2013

Contact: Clay Naito ([email protected]) 1

Water-Driven Debris Impact Forces on Structures: Experimental and Theoretical Program


Clay Naito, Ph.D., P.E. Associate Professor of Structural EngineeringAssociate Chair of Civil and Environmental EngineeringLehigh UniversityBethlehem, Pennsylvania USA

Research SeminarJune 25, 2013Sapienza Università di Roma



Presentation Summary

Lehigh University Research Interests – Prof. Naito Overview of Collaborative Blast Study Overview of Tsunami Demands Research Effort on Impact Demands

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Lehigh University

Established in 1865. Located in Bethlehem, PA 4700 Undergraduate Students 2200 Graduate Students 482 Full Tenure Track Faculty

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Department of Civil and Environmental Engineering

Ranked 17th in the US (US News and World Report) Department Organization Chair Prof. Panos Diplas Associate Chair Prof. Clay Naito

Areas of Expertise Structural Engineering (11 Faculty) Hydraulic Engineering (4 Faculty) Environmental Engineering (4 Faculty) Geotechnical Engineering (2 Faculty)

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CEE: Structural Engineering

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John Wilson, Ph.D.ProfessorDir. of Graduate StudiesMechanics

Paolo Bocchini, Ph.D.Assistant ProfessorComputational Mechanics and Reliability

• Ten Tenure Track Faculty • 3 Assistant, 2 Associate, 5 Full Professors• One Professor of Practice – Master of Eng. Program

Jennifer Gross, P.E.Professor of PracticeStructural Engineering

Stephen Pessiki, Ph.D.ProfessorFire and Earthquake Engineering and NDE Methods

Dan Frangopol, Sc.D.ProfessorSafety and Reliability

Shamim Pakzad, Ph.D.Assistant ProfessorStructural Health Monitoring and Sensor Networks

Clay Naito Ph.D., P.E.Associate ProfessorBlast, Impact, and Concrete Systems

James Ricles, Ph.D., P.E.ProfessorNEES DirectorSeismic Response and Retrofit of Steel Structures

Richard Sause, Ph.D., P.E.ProfessorATLSS DirectorSeismic and Blast Response of Structures

Peter Mueller, Sc.D.Associate ProfessorConcrete Mechanics



Degree Programs

Bachelor of Science Civil Engineering (50 students / yr) Environmental Engineering (15)

Graduate Degrees M.S. (13) & Ph.D. (13) Civil Engineering Master of Science (19) Structural Eng. Ph.D. Structural Engineering (38) Master of Engineering Structural Eng.

Current enrollment 23 1 year program (June – May)



Research Facilities

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Fritz Laboratory

ATLSS Research Center



Research Facilities

8

Fritz Laboratory• 5000 kip (22MN)

Universal Testing Machine

• Fatigue Testing Bed

• > 100 years of experimental research

ATLSS Research Center

• Large scale strong floor and wall.

• High speed actuators and DAQ

• Allows for full scale component and structure testing.



Research Facilities

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ATLSS Research CenterAdvanced Technology for Large Structural Systems

Sause – Tubular Flange Girder

Ricles – Buckling Restrained Brace Verrazano Narrows Bridge Deck Replacement - Roy



Throgs Neck Bridge, New York CityLoad Testing/Weigh-in-Motion

Infrastructure Deterioration &Simulation, Measurement, and Evaluation



Department Research Thrusts

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Infrastructure Reliability, Maintenance, and Life-Cycle Management

Infrastructure Deterioration

Infrastructure Hazard Mitigation

Intelligent Infrastructure

Simulation, Measurement, and

Evaluation

Advanced Structural Materials and Systems



Research Areas

Hazard Mitigation Seismic Mitigation

Development of a Seismic Design Methodology for Precast Concrete Diaphragms

Anti-Terrorism and Force Protection Blast Pressure Demands Ballistic Fragments – Structures / Personnel Close-in Detonation of High Explosives Progressive Collapse Design

Impact Demands from Accidental Impacts Debris Loading from Tsunami Events

Infrastructure Deterioration Evaluation and Assessment of Pretensioned Concrete Box Beams Use of New Materials – SCC and UHPC Implementation of NDE techniques into new construction

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Infrastructure Deterioration

Ultimate Strength of Self Consolidating Concrete Bulb Tee Beams

Pennsylvania DOT - Inspection Methods & Techniques to Determine Non Visible Corrosion of Prestressing Strands in Concrete Bridge Components

Federal Highway Administration - Designing and Detailing Post Tensioned Bridges to Accommodate Non-Destructive Evaluation



Development of Blast Resistant Structures (Trasborg / Olmati)

Research Efforts: Assessment of Precast Concrete Cladding Development of Enhanced Components

Full-Scale Blast Evaluation

Laboratory Static Evaluation

Breach Resistance to Close-in Charges

Wall Cladding Systems

Numerical Modeling



Collaborative Evaluation Effort

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National Science Foundation (NSF) funded a study by University of Missouri Kansas City(UMKC) to perform a batch of blast resistance tests on reinforced concrete slabs. The Blast Blind Simulation Contest is sponsored in collaboration with American Concrete Institute (ACI) Committees 447 (Finite Element of Reinforced Concrete Structures) and 370 (Blast and Impact Load Effects), and UMKC School of Computing and Engineering.



Prediction GoalGiven:• Material Properties• Blast Demands• Test ConfigurationDetermine:• Displacement time history, maximum and time of occurrence• Numerical – Crack patternFour Categories:• Normal Strength – Analytical Prediction (SDOF)• Normal Strength – Numerical Prediction (LS-Dyna)• High Strength – Analytical Prediction (SDOF)• High Strength – Numerical Prediction (LS-Dyna)

Research Team Institutions:Sapienza Università di Roma (SUR), Lehigh University (LU), and Politecnico di Milano (PM).Research Team Members: Pierluigi Olmati (SUR), Patrick Trasborg (LU), Dr. Luca Sgambi (PM), Prof. Franco Bontempi (SUR), and Prof. Clay Naito (LU).



Shock Tube

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Video of Test

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Input Data

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Normal Slab37 MPa of concrete strength

GR60 reinforcing steel

Hardened Slab80 MPa of concrete strengthVanadium reinforcing steel

0

10

20

30

40

50

60

0 20 40 60 80 100

Pres

sure

[psi

]

Time [msec]

PH-Set 2aPH-Set 2bLoad 1Load 2

LOAD



Slab Details

20- 20 March 2013 -



Numerical Modeling

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Number of nodes: 290628Number of solid elements: 270960Number of beam elements: 130

Reinforcements

LS-DYNA



Crack PatternNormal Slab

37 MPa of concrete strength / Gr.420 reinforcing steel

LOA

D 2

LOA

D 1



Response Estimate

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Normal Slab37 MPa of concrete strength / GR60 reinforcing steel

0

1

2

3

4

5

0 0.05 0.1 0.15

δ [in

ch]

Time [sec]

Load 1 Load 2



Hardened Slab – Crack Pattern

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80 MPa of concrete strengthVanadium reinforcing steel

LOA

D 2

LOA

D 1



Response of Hardened Slab

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Sla

bs



Results

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Normal Slab37 MPa of concrete strength

GR60 reinforcing steel


0

1

2

3

4

5

0 0.05 0.1 0.15

δ [in

ch]

Time [sec]

Load 1 Load 2



Results of Competition

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Four Categories:• Normal Strength – Numerical Prediction (LS-Dyna) – 1st place• Normal Strength – Analytical Prediction (SDOF) – 2nd place • High Strength – Analytical Prediction (SDOF) – 3rd place (unofficial)• High Strength – Numerical Prediction (LS-Dyna) – Not released

UpcomingPresentation – ACI Fall Meeting – Tucson ArizonaACI special publication

Research Team Institutions:Sapienza Università di Roma (SUR), Lehigh University (LU), and Politecnico di Milano (PM).Research Team Members: Pierluigi Olmati (SUR), Patrick Trasborg (LU), Dr. Luca Sgambi (PM), Prof. Franco Bontempi (SUR), and Prof. Clay Naito (LU).



Impact from Tsunami Generated Debris

Research Goals:Determine typical debris of concern Identify typical spread patternsDetermine forces generated during

impact




Water-Driven Debris Impact Forces on Structures: Experimental and Theoretical Program Clay Naito, Ph.D., P.E. Associate Professor of Structural EngineeringAssociate Chair of Civil and Environmental EngineeringLehigh UniversityBethlehem, Pennsylvania USA

Team: Ron Riggs (U.Hawaii) & Dan Cox (Oregon State U.)

Research SeminarJune 25, 2013Sapienza Università di Roma



Tsunami Demands

Inundation Rapid ~ 30 minutes after event• Japan• US Northwest and Alaska



NSF Rapid: Impact of Debris Generated from the Tohoku Tsunami

Field Team:1. Clay Naito (Lehigh U.)2. Dan Cox (OSU)3. Kent Yu (Degenkolb)4. Daiki Tsujio (Pacific)5. Prof. Mizutani (Nagoya)Travel Itinerary:1. Natori2. Minamisanriku,

Kesennuma, Rikuzentakta3. Sendai4. Onagawa, Ishinomaki5. Sendai, Natori

2011 Japan ReconnaissanceOverview




Debris and Structural Damage• Debris Considerations Observed

– Natural and Manufactured Wood– Vehicle Debris– Shipping Containers– Boats/Ships– Fuel Storage Containers

• Structural System Types– Reinforced Concrete Buildings– Steel Buildings– Wood Frame– Utility Distribution




Wood DebrisPhoto:

Y. Okuda

BRI Japan

Photo: Y. Okuda BRI Japan

Natural DebrisInundation

Natural DebrisRundown

Wood Frame Structure Debris Debris Field




Vehicle Debris

Floating Debris

Debris Field

Entry intobuildings

Damming ofVehicles

Debris Settlement




Boat/Ship Debris Debris Settlement

Contribution toTsunami Forces

Vessel SizeNatori

Kessenuma

Impact Forces Minamisanriku

Ishinomaki

Kessenuma




Shipping ContainerDebris Ofunato, Japan

Sendai, Japan

• Container Ports Common

• Containers Float

• Debris in port

• Debris in region




Shipping Containers

Building Impact

Light Pole ImpactFailure Modes

Quantified




Other Debris

Wood Debris

Stairways

Cladding




Fuel Storage Containers• Failure of Fuel Storage

Containers• Loss of Anchorage• Impact damage to

structures• Fuel containment failure

and contamination to areas.



Impact Damage



Debris Site Assessment

Point-source debrisShipping container yardsPorts with barges/ships

Site assessment procedureDetermine potential debris plan area

Number of containers * area of a containerDefine debris concentration: area of debris/land area2% concentration defines debris dispersion zone



Sendai (Containers)



Sendai (Containers)



Natori (Vessel Spread)



Goals of NEES Research Study

Determine the debris impact forces from tsunami generated debris on structures

Flexible debrisLow velocity, ‘moderate’ massConsider fluid effects and (container) contents

Provide relatively simple design formulasImpact force and duration

Tsunami Loading, Ftotal

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Longitudinal ImpactTree, pole or container hitting a column head-onColumn modeled as a massless spring, ks

Transverse ImpactTree or pole hitting a column transversely

Analytical Models–Wave Propagation

L

ks

x v0

L1

ks

L2

x

v0 ω0



Longitudinal ImpactRigid impact force:Duration:

Rigid limit works wellSimplest formula

Transverse ImpactRigid impact force

Longitudinal impact force is usually larger

Focus on longitudinal impact

Impact Forces

Fl EAv0 kmv0td 2L / c0 2mvo Fl

0 02 2t shF G Av k mv



Utility pole6 m longTapered from 0.267 m to 0.216 m diameter204 kgAbout ½ the weight of the ‘basic’ design log of ASCE 7-10 (Flood)

Pendulum test setup

Lehigh In-Air Tests

Load cell down here (not shown)



6.1 m x 2.4 m x 2.6 m and 2300 kg empty

Containers have 2 bottom rails and 2 top rails

Pendulum setup; longitudinal rails strike load cell(s)

ISO 20-ft Shipping Container



Shipping Container Impact



Impact velocity 1.3 m/s

One bottom rail of container hit

Impact Force Time History

0

50

100

150

200

250

300

0 5 10 15 20 25 30

ContainerWood Pole

Impa

ct F

orce

(kN

)

Time (msec)



Impact Force Time Histories

F ≈ 560 kN per m/s

F ≈ 114 kN per m/s



Actual force divided by the analytical impact force

1.0 would mean perfect alignment

Nondimensional Maximum Impact Force



Actual duration divided by the analytical duration

Nondimensional Impact Duration



Large wave flume: 110 m long; 3.7 m wide; 4.6 m deep

1:5 scale container hits column at nearly the flow speed

Multiple water depths and drafts were considered

OSU In-Water Tests



Guide wires controlled the trajectory

Container hits underwater load cell to measure the force

Aluminum and Acrylic Containers

Column and load cell at top of photo



In-air tests carried out with pendulum set-up for baseline

In-water impact filmed by submersible camera

Impact was on bottom plate to approximate longitudinal rail impact

Impact

In-air impact In-water impact



Insert video

Impact



Side View



In-water impact and in-air impact very similarLess difference between in-air and in-water compared to scatter between different in-water trials

Force Time-History



Each symbol style represents unique water depth and draft combination

Solid black line is the predicted force based on in-air tests

Maximum Impact Force vs. Speed



Conclusions

Simple formula for design impact forces validated by experimental data

Assumptions are conservative

Container contents don’t affect impact force significantly, although duration can be increased

Results indicate fluid doesn’t affect impact force substantially

Other conservative assumptions compensate for slight conservatism in ignoring it

Results are the basis for the proposed debris impact forces in ASCE 7



Acknowledgements

This material is based upon work supported by the National Science Foundation under Grant No. CMMI-1041666; REU students supported by Grant No. CMMI-1005054; Tohoku survey supported by Rapid Grant No. CMMI-1138668.

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation

REU students Amy Kordosky, Patrick Bassal, and Andrew Lopes helped with the OSU and LU tests.

George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES)



Thank you.

Stro N

GERwww.stronger2012.com

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Sapienza naito-25-06-13