1. Protocols for Modeling Explosive Threats in Urban Environments
3/25/2017
3/25/2017
CRTI RD
Protocols for Modeling Explosive Threats in Urban Environments
R.C. Ripley, F. Zhang, D. Whitehouse, L. Donahue,
K. Scherbatiuk, F.-S. Lien, P. Caron
CRTI Summer Symposium 2009, June, Ottawa 1

2. Project Team Public Safety Canada (Lead Dept.):
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Project Team
Public Safety Canada (Lead Dept.):
Pierre Caron (PM), Tim Patraboy (DPM), Glenn Flood
DRDC Suffield:
Fan Zhang (SA), Kevin Scherbatiuk (Structural)
Martec Limited:
David Whitehouse (Protocols), Robert Ripley (Models & UE Solutions), Laura Donahue, Eric Li (PV), Tim Dunbar (SV)
University of Waterloo:
Prof. Fue-Sang Lien (Models), T. Xu, H. Ji
RCMP:
Sgt. J.-Y. Vermette

3. 3/25/2017
Introduction
Modeling is a key tool to support analysis of terrorist explosive threat impact on Canadian urban targets
Need reliable approaches for generating and delivering information to decision makers

4. Blast Interaction Regimes
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Blast Interaction Regimes
Suffield Scaled Urban Street
Unconfined Free-Field Blast

5. Urban Street Explosion
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Urban Street Explosion

6. 3/25/2017
High Confinement
Subway
Train Station
Parkade
Tunnel

7. Simple Models are Not Always Sufficient
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Simple Models are Not Always Sufficient
Oklahoma City (1995)
Moscow (1998)
Risk Management Series FEMA 426 (2003)

8. 3/25/2017
Urban Blast Modeling
High-fidelity, first-principles model

9. Capability and Knowledge Gaps
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Capability and Knowledge Gaps
Fast and approximate modeling tools do not properly address near-field scenarios found in urban environments
Lack of physical models for non-ideal explosives in close proximity to urban structures
Lack of supporting documentation and corresponding guidelines for effective use of modeling tools

10. 3/25/2017
Objective of CRTI RD
To develop protocols serving as standards and guidelines for modeling both ideal and non-ideal explosive threats in close proximity to urban structures and environments

11. What are the Blast Modeling Protocols?
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What are the Blast Modeling Protocols?
Guidelines to be followed when performing/evaluating blast analyses for threats in urban environments
A series of sequential steps which cover the blast analysis process
Consider best-practice modeling while not restricting analyses to specific approaches
A key feature is a set of baseline urban test cases
Database of accurate pre-computed urban scenarios for quick analyses
Used to evaluate the range of applicability of any blast modeling approach for a specific urban blast event

12. 3/25/2017
Project Roadmap

13. Eight Protocols Steps Define and Interpret Pre-Calculation Guidance
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Eight Protocols Steps
Define and Interpret
Pre-Calculation Guidance
Calculation Steps
Analyze and Summarize

14. Who are the Protocols Users?
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Who are the Protocols Users?
Performers
Focus on performing and delivering results from a specified blast analysis
Consumers
Understand the context of blast problem which needs to be solved
Provide advice to outside groups
Manage the resources on projects addressing security issues, which may include the blast analysis
Decision Makers
Take action based on the analysis results
Interested in how protocols reduce their risk

15. Pre-Calculated Scenario Matrix
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Pre-Calculated Scenario Matrix
A total of 300 scenarios are planned
Include range of targets and threats

16. Fundamental Urban Elements
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Fundamental Urban Elements
U1: Straight Street
U2: Single Building
U5: Street Intersection
U3: Urban Bay
U4: Urban Corner
U6: Alley Intersection

17. 3/25/2017
Structural Elements

18. Classes of Explosives (Tentative)
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Classes of Explosives (Tentative)
HE (C4, TNT)
Energetic Liquids (TATP etc.)
Slurries (ANFO)
Energetic Liquid/Metal Particles (NM/Al, Mg, Ti, Zr)
Aluminized AN
Organic Powder – Based Mixes (Corn Starch)
Granular Explosive (pipe bombs)
FAE (Liquid HC Fuel into Air)
Coordinated with CRTI RD ‘Improvised Explosive Assessment’ and CRTI RD ‘Transport of Combustible Liquids’

19. Preliminary User Survey Results
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Preliminary User Survey Results
Urban Environments
Description
Rating (5 high)
4-Way Street Intersection
4.7
Parkade (small and large)
Straight Street 4
Internal Blast
3.8
Side-Street Alley
3.7
Urban Bay
3.6
Bridge Underpass
3.5
Tunnel Entrance
3.4
Single Building Façade
3.2
Bridge Tunnel
Blast Threats
Type
Rating (5 high)
ANFO
5.0
TNT
4.8
AN+other
Liquid Hydrocarbon
3.9
Liquid (NM, IPN)
3.3
Aluminized
3.1
TATP
3.0
Additional user surveys planned within the CRTI community

20. Blast Enhancement Table
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Blast Enhancement Table
# Walls 1 2 3 … 4 5 6
Elements →
Free-Field
Single Building
Parkade
Street
Tunnel
Courtyard/
Market
Interior Room
Threats ↓
TNT
1.0
6.0
10.0
11.0 C4
1.2
7.2
11.5
12.0
ANFO
0.8
4.5
7.8
8.4
Aluminized Explosive
1.5
FAE

21. Blast Enhancement Table
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Blast Enhancement Table
# Walls 1 2 3 … 4 5 6
Elements →
Free-Field
Single Building
Parkade
Street
Tunnel
Courtyard/
Market
Interior Room
Threats ↓
TNT
1.0
6.0
10.0
11.0 C4
1.2
7.2
11.5
12.0
ANFO
0.8
4.5
7.8
8.4
Aluminized Explosive
1.5
FAE

22. 3/25/2017
Physical Models
Required for simulating detonation and near-field blast from classes of conventional and non-ideal explosive threats, and their interaction with confined urban environments

23. Confined Explosive Afterburning
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Confined Explosive Afterburning

24. Confined Explosive Afterburning
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Confined Explosive Afterburning
Donor Chamber
t = 5.7 ms
t = 10.7 ms
t = 20.7 ms
Acceptor Chamber
t = 50.7 ms

25. Aluminum Detonation in Air
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Unconfined Detonation
Aluminum Detonation in Air
Micrograph of particles
Abrupt DDT
DDT process in a closed tube
Ea=71 kJ/mol
Ea=120 kJ/mol

26. Non-Ideal Explosive Analysis
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Non-Ideal Explosive Analysis

27. Dense Multiphase Flow Mixing Models
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Dense Multiphase Flow Mixing Models
Particle jetting / wake and boundary layer interaction
D.L. Frost, MABS 19

28. Status and Plan FY08-09 Physical models implemented (Del #3 and 4)
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Status and Plan
FY08-09
Physical models implemented (Del #3 and 4)
Protocol prototype design complete (Del #5)
First user meeting completed (users and scenarios)
FY09-10
Physical models validation underway
Scenario calculations to begin after matrix finalization
Protocol platform selection under review
Additional user feedback meetings
Protocol process requires testing and design iteration
Final Protocols ~ June 2011

29. 3/25/2017
Questions?

30. Vulnerability Guidelines
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Vulnerability Guidelines
Structural Response for Non-Uniform and Complex Blast
Combined Human Injury Chart

31. Particle Fragmentation
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Particle Fragmentation
Detonation Fragmentation
Thermal Cracking
Impact Fragmentation
Aerodynamic Fragmentation
Reflection
Wall Coating

32. Protocols Steps – Top Level
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Protocols Steps – Top Level
There are 8 steps for performing blast analyses:
Attributes
Sequential
Modular
Reproducible
Auditable
Define and Interpret
Pre-Calculation Guidance
Calculation Steps
Analyze and Summarize

33. Protocols Steps – Process Details
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Protocols Steps – Process Details