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8/9/2019 Blast Design Oswald
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8/9/2019 Blast Design Oswald
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DoD Antiterrorism RequirementsDoD Antiterrorism Requirements UFC 4-010-01 DoD Mimimum Antiterrorism
Minimum standoff distances from controlled perimeter andparking to inhabited buildings
Window and window frame design standards
Progressive collapse avoidance standards
A lies to new buildin s and renovations orrepairs > 50% of building replacement cost
Minimum standoffs can be reduced if justified
y as ana ys s an or u ng ar en ng
STEER Meeting, March 22, 2007
8/9/2019 Blast Design Oswald
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Government Building RequirementsGovernment Building Requirements Interagency Security Committee (ISC) Security
Antiterrorist design requirements for U.S. governmentbuildings
Blast design requirements usually apply onlyfor large federal buildings (e.g. courthouses,FBI buildin s
Building structural member and windows must resist specifiedexternal blast loads depending on required level of protection
Progressive collapse avoidance requirements
Requirements for vehicle barriers around building
STEER Meeting, March 22, 2007
8/9/2019 Blast Design Oswald
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Explosive Storage and ManufacturingExplosive Storage and Manufacturing
State and federal safety requirements for
Protect against accidental explosion scenario
Typically requirements satisfied withprescribed standoff distances
Otherwise, personnel protection from blast,,
designed
Personnel may be in same building or in nearby building
Design to contain explosion effects in explosion room
Design of surrounding buildings if explosion not contained
STEER Meeting, March 22, 2007
8/9/2019 Blast Design Oswald
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Industrial Building RequirementsIndustrial Building Requirements Many industrial processes may cause accidental
Petrochemical and chemical manufacturing processes
OSHA 1910 requires blast siting analysis
Consequences must be estimated from credible explosionscenarios
explosion effects
Typically building occupants more at risk than personnel in
open ue o n ury rom a e u ng componen s Buildings may require blast resistant structural upgrades to
provide required protection
STEER Meeting, March 22, 2007
8/9/2019 Blast Design Oswald
6/21
General Blast Design ApproachesGeneral Blast Design Approaches Single-degree-of-freedom (SDOF) approach
Combines explicit consideration of non-linear dynamicresponse with design level simplicity
Equivalent static load (ESL) approach
Used for connections and other stiff members includingbracing and shear walls subject to reaction loads
Most accurate if dynamic load application is slow compared tocomponent response time, or natural period (i.e. no inertialeffects)
Dynamic finite element analyses
Non-linear dynamic analysis
STEER Meeting, March 22, 2007
8/9/2019 Blast Design Oswald
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Basic Blast Design AssumptionsBasic Blast Design Assumptions Material yield strengths increased for strain-
Fast response causes high strain-rate and greater yieldstrength (10% to 20% increase)
design
Yielding of component in ductile response
Strengthen non-ductile response modes so they dont controlresponse
es gn ase on a owa e e ec on ra erthan allowable stress Typical design allows one-half of failure deflection
STEER Meeting, March 22, 2007
8/9/2019 Blast Design Oswald
8/21
SDOF Design ProcedureSDOF Design Procedure Calculate dynamic load
Use dynamic reaction load from cladding on framingcomponents
Calculate maximum dynamic deflection
Use equivalent SDOF properties of structural component andblast load to calculate maximum deflection with SDOFprocedure
Usually ductile flexural response is assumed
deflection criteria
STEER Meeting, March 22, 2007
8/9/2019 Blast Design Oswald
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SDOF Design Procedure (Contd)SDOF Design Procedure (Contd) Must check for any instability or brittle failure
Strengthen brittle/instable failure mode so it does not controlultimate strength
Alternatively, reduce allowable deflection and ultimatecapacity
Must follow load path to foundation Connections
Diaphragms
Rigid body motion of building
STEER Meeting, March 22, 2007
8/9/2019 Blast Design Oswald
10/21
Shock Wave Applying Blast to BuildingShock Wave Applying Blast to BuildingPRESSURE
TIME
AMBIENT
PRESSURE
PEAK
PRESSURE
soP
Pr Building Pb