s chirmer e ngineering c orp. performance-based codes & concepts daniel j.o’connor, p.e
TRANSCRIPT
SCHIRMER ENGINEERING CORP.
PERFORMANCE-BASED CODES & CONCEPTS
Daniel J.O’Connor, P.E.
SCHIRMER ENGINEERING CORP.
PERFORMANCE-BASED CODES & CONCEPTS
Daniel J.O’Connor, P.E.
SCHIRMER ENGINEERING CORP.
Topics for Today’s Presentation
High Level - Overview of Performance-Based Developments & Documents
Systems Level – Estimating Relative Effectiveness of Smoke Detectors on Complex Ceilings
Human Behavior Perspective – Using technology to Improve Evacuation Effectiveness
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Current Documents With Performance Based Design Methods
BOCA National Building Code• Alternative materials & methods provisions• Example: Section 922.0, Smoke Control Systems
NFPA 101 & 101m Uniform Building Code; Standard Building
Code; International Building Code International Codes and Standards
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Documents With Performance Based Design Methods
NFPA 92B: Smoke descent; Fire Plumes; Detector Activation
NFPA 555: Flashover; Target Ignition NFPA 72: Response of Fire/Smoke
Detectors NFPA 80A: Exposure Fire Heat Transfer
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International Documents
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International Code Council
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Performance Building Code Intends To Provide For….
NON-FIRE RELATED ISSUES A structure which will withstand reasonable loads
associated with normal use, and wind, snow or earthquake for the severity associated with the location in which the structure is constructed
A design which provides reasonable access Adequate ventilation and sanitation facilities to maintain
the health of the occupants Adequate arrangements for natural light, heating,
cooking, and other amenities needed for the comfort of the occupants
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Performance Building Code Intends To Provide For….
FIRE RELATED ISSUES An environment free of unreasonable risk of
death and injury from fires
A design which provides reasonable means of egress
Reasonable arrangements to limit the spread of fire within the building and to adjacent properties
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Structure of Provisions
Objectives Functional Statements Performance Requirements
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Example Provisions - Fall Prevention
Objective To prevent people from unintentionally
falling from one level to another Functional Statement
Buildings and their facilities shall be constructed to reduce the likelihood of unintentional falls
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Example Provisions - Fall Prevention
Performance Requirements• Barriers shall be provided where people
could fall 30 inches or more• Roofs with permanent access shall have
barriers provided• Barriers shall be installed and constructed
appropriate to the hazard• When barriers have openings, the openings
shall be of size / configuration to keep people from falling through, based upon age
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Example Provisions - Means of Egress Objective
To provide a reasonable means of safeguarding people during escape and rescue operations
Functional Statement Means of egress shall give people adequate time to exit the building or reach a safe place
without being exposed to untenable conditions
Performance Requirements• Provide a system of vertical and horizontal travel to safety in the event of an emergency• Means of egress shall be of adequate size for the number of occupants and shall be
maintained free of obstructions• Means of egress shall be clearly identified, adequately illuminated, easy & safe to use, etc.
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Example Provisions - Stability
Objective To provide a desired level of structural performance when subjected
to the loads that are expected during construction, alterations and throughout the structure’s life
Functional Statement• Structures shall be designed / constructed to prevent injury to
occupants due to loading of a structural element or system consistent with determined design performance levels
• Structures shall be designed / constructed to prevent loss of property and amenity consistent with determined design performance levels
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Example Provisions - Stability
Performance Requirements• Structures shall remain stable and not collapse during
construction, alteration and throughout their lives• Structures shall be designed to sustain local damage, and
the structural system as a whole shall remain stable and not be disproportionately damaged
• Structures shall have a low probability of causing damage or loss of amenity through excessive deformation, vibration, or degradation
• Structures shall be designed / constructed to taking into account all expected loads and combination of loads associated with event(s)/magnitude(s) that affect their performance
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National Fire Protection Association
Chapter 5 (New in 2000 ed.) - Performance-Based Option
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NFPA Life Safety Code Key Feature – eight required design fire scenarios
• Typical occupancy fire
• Ultra-fast fire in corridor w/doors open
• Fire in unoccupied room potentially endangering large
population
• Fire in concealed wall or ceiling space
• Slow developing fire, shielded from suppression, in proximity
to large population
• Most severe fire from largest fuel load characteristic
• Outside fire exposure
• Fire with each passive or active fire system rendered
ineffective
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Society of Fire Protection Engineers
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SFPE ENGINEERING GUIDEPerformance-Based Design Process
Defining Project Scope(Chapter 4)
Identifying Goals(Chapter 5)
Defining StakeholderAnd Design Objectives
(Chapter 6)
Developing PerformanceCriteria (Chapter 7)
Developing Design FireScenarios (Chapter 8)
Developing Trial Designs(Chapter 9)
Evaluating Trial Designs(Chapter 10)
Selected DesignMeets Performance
Criteria?
Select the Final Design
Prepare DesignDocumentation
Modify DesignOr Objectives
Specifications, Drwgs, and Operations and Maintenance Manual
Chapter (12)
Developing a Fire Protection Engineering
Design Brief(Chapter 11)
Performance-BasedDesign Report(Chapter 12)
No
Yes
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Common Factors in Performance-Based Design
Goals, Objectives, Performance Criteria Design Specifications and Conditions Site, Building, Occupant Characteristics, etc. Design Scenarios Evaluation: Data, Uncertainty, Results, Validity Safety Factors Documentation Peer Review
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Advantages of Performance-Based Approach
Specifically Addresses:• Unique Building Features• Client Needs• Building Use Considerations• Proposed Alternatives
Assessment of Code Requirements Increased Engineering Rigor / Peer Review Comprehensive Systems Overview
• Integration of Systems• Cost Effectiveness
Improved Knowledge of Loss Potential
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Disadvantages of Performance-Based Approach
AHJ’s Reluctance to Approve PB Approach• Unfamiliar with Methodology• Lack of Knowledge of Science Creates Tendency to
Disagree with or be Skeptical Of:– Approach, Objectives, Certainty
• Perception that Anything Less than Code is not “Safe”
Qualifications of Designer / Reviewer More Design/Engineering Time Occupancy Changes May Require Re-analysis
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Projects Using Fire / Smoke Modeling & Timed Egress Analysis
Grand Central TerminalNew York, NYTravel Distances Greater Than 1000 feet
US Supreme CourtWashington, DCFire Modeling & Egress Analysis to Support Long Travel Distances Down Open Stairs
McCormick Place South HallChicago, ILTravel Distances Exceeded Code Limits; Used Alternative Exit Capacity Factors to Reduce Exits Serving 40,000 Persons
Great American PyramidMemphis, TNFire Hazard Analysis Proved Safe Egress Time From Observation Level
Paris CasinoLas Vegas, NevadaFire Modeling to allow for use of unprotected Steel concepts and safe egress from ½ scale Eiffel tower
Amtrak Rail Tunnel SystemNew York, NYFire Modeling to Improve Life Safety and Fire Protection