Transcript Building Collapse Awareness - LSU Fire and Emergency
Office Of The State Fire Marshal OF Illinois Rescue Specialist Certification Program 1998 1
COURSE OVERVIEW
Scope Knowledge Base To Identify Collapse Conditions Knowledge To Determine Type Of Structure Provide Tasks For First In Companies Establish ICS / IMS Assess Incident Magnitude Identify Potential Hazards Surface Rescue Of Accessible Victims 2
COURSE OVERVIEW
(CONTINUED)
Requirements Firefighter II Course Completion End Of Course Exam State Written Exam Review Objectives In Manual 3
STRUCTURAL COLLAPSE AWARENESS
Causes
Dangers
Rescues
4
CAUSES
Tornadoes Wind Storms Floods Vehicle Accidents Construction Accidents Fires 5
ASSOCIATED DANGERS
Secondary Collapse Gas & Electrical Hazards Fire Explosions HazMat Spills Uncontrolled Animal Life High Number Of Initial Injuries Uncontrollable Crowds 6
RESCUES ARE RARE
Minimal Number Of Incidents Dangerous Due To Lack of Experience Limited Funding For Training & Equipment Hazards Are Hidden False Sense Of Security May Require Numerous Unusual Resources 7
GENERAL PRINCIPLES
Strategies Of Initial Size-Up Principle of Collapse Awareness Initial Spontaneous Response Planned Community Response Void Space Rescue Technical Urban Search & Rescue 8
STRATEGIES OF INITIAL SIZE-UP
Assess Affected Area Scope & Magnitude Of Incident Number Of Structures Involved Size Of Structures Involved Integrity Of Affected Structures Stability Of Affected Structures 9
STRATEGIES OF INITIAL SIZE-UP (CONTINUED)
Evaluate Each Area Occupancy Types Number Of Known / Potential Victims Availability Of Access To The Scene Environmental Factors That Affect The Incident Available / Necessary Resources Needed 10
PRINCIPLES OF STRUCTURAL COLLAPSE AWARENESS
To Save Trapped Victims From Around Collapsed Structures, While Minimizing The Risk To Them And To Rescue Personnel 11
PRINCIPLES OF INITIAL SPONTANEOUS RESPONSE
Types Of Responders Remove Surface Victims Remove Lightly Trapped Victims Accounts For 80% Of Total Rescues 12
PRINCIPLES OF INITIAL RESPONSE
(CONTINUED)
Survival Rate Relatively High Skilled Responders Can Participate Better Organize The Response 13
PRINCIPLES OF A PLANNED COMMUNITY RESPONSE
Community Response (Awareness Level) First In Fire Companies Police / Local Emergency Management / PW Rescue Non-Structurally Trapped Call-out / Hail System Visual Search Light Lifting Of Contents Light Hazard Mitigation 14
VOID SPACE RESCUE
Technical Rescue Teams Trained Personnel Risk / Benefit Decision Accessing Voids Thru Existing Openings Cut Small Openings - Walls / Floors Shoring Provides Safety for Rescuers / Victims 15
TECHNICAL US&R
Technically Trained Rescue Forces Specialized Equipment To Perform Operation Immobilized For A Ten-Day Long Effort Selected Sites Re-evaluated Re-searched Prioritized Extensive Cutting and Shoring Cranes May Be Used 16
DESTRUCTIVE FORCES
Earthquakes Wind Floods Snow Heavy Rain 17
DESTRUCTIVE FORCES
(CONTINUED)
Construction Problems Explosions Structural Decay Fire Transportation Accidents 18
EARTHQUAKES
Cause Shaking Greatest Effect Weak / Heavy Structures Structures Dynamically Coupled With Their Sites Model Building Codes 19
WIND
Hurricanes And Tornadoes Cause Damage Wind Velocity Airborne Missiles Tidal Surges Differences In Atmospheric Pressure Light Non-engineered Buildings And Structures Penetration Leading To High Uplift Blowout Forces 20
FLOODS
Riverine Flooding Flash type Rapid water rise High velocity May Produce A Wall Of Water Effect Other Type Slow Unconfined Flow Over A Low Lying Broad Area 21
FLOODS
(CONTINUED )
Coastal Flooding Caused By Severe Storms May Be Combined With High Tides Step Up Surges Of Hurricanes Combined With Their High Winds Produce Combined Forces From Wind And Flooding 22
FLOODS
(CONTINUED)
Flooding Damage Hydrostatic Lateral Pressure / Lifting Hydrodynamic Forces Due To Velocity Wave Height Debris Impact From Waterborne Objects 23
SNOW AND HEAVY RAIN
Roof Collapse Due To Overload Occurs In Long Span Construction With Relatively Flat Roofs Roof beams / Trusses Fail = Partial Collapse Snow Buildup Can Cause More Complete Collapse Due To Failure Of Vertical Supporting Elements 24
CONSTRUCTION PROBLEMS
Lack Of Temporary Lateral Bracing Inadequate Vertical Shoring Failures can occur During Concrete Pours While Placing Large Roof Beams And Trusses While Lifting Large Concrete Slabs Other Overloads Stockpiling Of Materials Non Engineered Alterations 25
EXPLOSIONS
Gas buildups Natural gas Propane Anhydrous ammonia Smoke explosions Bombs Dusts W/ Less Than 5’ Visibility 26
EXPLOSIONS
(CONTINUED)
Effect Lightweight Wood and Steel Components Weakest Part Blown Out to Reduce the Pressure Entire Roof or Wall May Be Blown Out Reinforced Concrete Structure Contains Blast Greater Loss of Life Floor Collapse If Columns and Walls Are Damaged Precast Structure Very Vulnerable Large Concrete Parts May Become Disconnected Or Blown Out Leading to Progressive Collapse 27
STRUCTURAL DECAY
Collapse of older buildings and bridges Vertical Members Fail Leading To Multi-Floor Collapse Unreinforced Masonry Walls Can Be Left Full Height Walls Could Fall In On Floor Debris Pile Out Into The Street Into Adjacent Buildings Very Dangerous 28
FIRE
Wood or Metal Roofs / Floors Often Collapse Due To Burn Through Can Pull Exterior Masonry / Concrete Wall In Leave Them In An Unbraced Condition Steel Structures Have Less Strength Due To The Loss of Original Heat Treatment Remaining Concrete Structures Can Be Damaged Due To Spalling Concrete Shear Walls Can Be Cracked Due To The Expansion Of Floors 29
TRANSPORTATION ACCIDENTS
Vehicular And Other Transportation Accidents Have Caused Collapse Due To Impact Spillage Of Large Quantities Of Materials 30
INITIAL INFORMATION GATHERING
Critical To The Transition Of The Technical Rescue Teams (TRT) In To The Incident Trts Shall Verify All Information Obtained From the First Responders The Physical and Emotional Issues First Responders Have Encountered Physically and Emotionally Draining Work Not Believing Any Others Have Survived Emotions of the Relatives and Friend of the Missing Rescuers Tend to Experience Closure of the Incident Prematurely 31
INITIAL INFORMATION GATHERING
(CONTINUED)
Gather Information Swiftly And Unemotionally as Possible Test Current Assumptions Record Structural Information Verify Information With Your Own Assessment 32
IDENTIFICATION OF BUILDINGS
A Standardized System Shall Be Used To Locate A Building On Any Block Use Existing Numbers Fill In Numbers Unknown Due To Damage If All Are Unknown – Keep All Numbers Small – Odds One Side – Evens The Other 33
STANDARD SYSTEM FOR BUILDING LAYOUT
Sectors A, B, C And D Start at street and go clockwise If more than 4 sides use more letters Multiple Stories Are Designated Utilize Existing Building Designations Sector 1, 2, 3, 4, etc.
Basements Are Designated Utilize Existing Building Designations B1, B2, B3, etc.
34
QUADRANTS WITHIN THE BUILDING
Quadrant 1 Quadrant 2 Quadrant 3 Quadrant 4 35
BUILDING TRIAGE
Disasters That Have Many Seriously Damaged or Collapsed Buildings Require a Method to Prioritize Them Method Must Identify and Quantify Criteria That Will Have a Higher Probability of a Successful Rescue Method Should Also Be Simple Enough So That All Levels of Rescuer Can Effectively Perform It Happens Immediately After the Disaster 36
BUILDING TRIAGE
(CONTINUED)
Recon/Evaluation Teams Prioritize All Affected Structures To Aid In Response Planning Local Emergency Responder May Triage To Evaluate The Overall Impact And Evaluate Their Own Priorities USAR Teams May Triage To Prioritize Multiple Buildings In Their Assigned Areas Or Even triage To Prioritize Sections Of A Large Structure 37
BUILDING ASSESSMENT
Time Of Day Occupancy Structural Type Building Age Collapse Mechanism Prior Intelligence Search And Rescue Resources Available Structural Condition Of Building 38
STRUCTURAL CONDITION OF BUILDING
Is Stabilization Needed?
None Minor Extensive Danger of Additional Collapse Low Probability High Probability 39
STRUCTURAL CONDITION OF BUILDING
(CONTINUED)
“NO GO” Conditions Structures on Fire HazMat Spills Any Other Conditions That Make Search & Rescue Too Risky 40
BUILDING MARKING
Developed To Inform The Emergency Responders Of The Hazards Based On 2 Ft. By 2 Ft. Square Using Orange Spray Paint Placement Adjacent to the Most Accessible Point of Entry After the Structural/Hazards Evaluation Has Been Completed 41
DETAILED STRUCTURAL EVALUATION
Only After Priority List Of Structures Is Established Utilize Check-off Sheets 42
RESCUE TEAMS DEALING WITH RED TAG STRUCTURES
Greatest Concern Partially collapsed buildings Term “Safe” Different from safe for occupancy All structures are deemed damaged Safe for rescue team is a value judgment 43
RED TAG STRUCTURES
(CONTINUED)
Specialists to Work in Pairs to Evaluate Structures Rescue Specialist Hazmat Specialist Second Opinions Are Critical Place Evaluation Marking on Building Near Each Entry UHR-4B (Page 91) 44
SEARCH & RESCUE ASSESSMENT MARKING
Functions
Search In Progress Search Completed w/ Outcome 45
STRUCTURAL MEMBERS AND VERTICAL LOAD SYSTEM
There Are Three Major Fundamentals of Structural Design. These Fundamentals Follow the Laws of Gravity, With Each Resisting It in a Certain Manner. These Fundamental Concepts Are: Horizontal Members Vertical Members Combination Trusses 46
HORIZONTAL MEMBERS
Span From Vertical Support To Vertical Support Must Have Strong Tensile Attributes Have Little Or No Compressive Values 47
HORIZONTAL MEMBERS
(CONTINUED)
Materials; Steel, Concrete And Wood Steel Suited For Horizontal Design High Tensile Values Concrete Compressive In Nature Requires Addition of Steel Reinforcing Wood Limited Compressive Values Limited Tensile Qualities 48
VERTICAL MEMBERS
Provide Support For Horizontal Or Spanning Members Need Strong Compressive Attributes With Little Or No Tensile Values 49
VERTICAL MEMBERS
(CONTINUED)
Materials; Steel, Concrete And Wood Steel Tensile in nature Low compressive value Concrete Suited for vertical design Requires addition of steel reinforcing Wood Limited compressive values Limited tensile qualities 50
COMBINATION TRUSSES
Structural Members Utilize Both Properties Of Structural Design, Vertical & Horizontal Members, To Maintain Integrity 51
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COMBINATION TRUSSES
(CONTINUED)
Components Function In Both Tension And Compression In Normal Spans
Top chord
is typically compressive in nature, attempting to push or hold components apart
Bottom chord
is typically tensile in nature, attempting to downward forces due to loading
Intermediate components
function in both tension and compression. Working to resist forces of top and bottom chord pulling together 52
MATERIAL PROPERTIES
There Are Four Fundamental Materials Utilized for Building Construction. Each Specific Material Has Its Own Limitations and Benefits When Associated With Specific Building Size, Height and Structural Integrity. These Materials Include; Wood Steel Concrete Masonry - Reinforced & Unreinforced 53
WOOD
Tough, Fibrous, Natural Material Strength Contingent on Species Inherent Defects Cause Stress Concentrations. I.E.... Knots, Splits and Uneven Grain Wood Strength Is Classified As Bending Stress (Fb), Contingent on Species 54
WOOD
(CONTINUED)
Since Wood Is Natural Fibrous, It Provides Additional Structural Benefits, Such As; Nailed and Bolted Connections Adequately Secure Members Wood Sheathing of Structures Provides Good Earthquake Resistant Design, Contingent on Adequate Nailing 55
STEEL
Tough, Light, Ductile and Man Made.
Steel Must Be Fire Proofed to Ensure Structural Integrity Steel Is Often Considered the Ideal Building Material Steel Can Be Slightly Damaged or Bent and Still Maintain Structural Integrity Warning of Structural Collapse Is Evidenced by Sagging Members 56
STEEL
(CONTINUED)
Structural Steel Can Be Efficiently Connected by Bolting, Welding or Riveting (Riveting Is Typical to Older Structures) Steel Framing Must Be Braced to Prevent Weakening or Buckling 57
CONCRETE
Strong Compressive Abilities With Minimal Tensile Strength.
Steel Reinforcing Is Typically Added to Provide Additional Strength.
Longitudinal Steel
: Tension Members In Concrete Beams
Stirrups
: Shear Resistance In Beams At Support
Horizontal Ties
: Confine Steel In Place 58
CONCRETE
(CONTINUED)
Concrete Can Be Strengthened As Follows; Pretensioned: Cables Are Pre-Stressed Prior to Placement of the Concrete and Cast Directly in Poured Concrete.
Post-Tensioned: Cables Are Placed in Continuous Sleeve Prior to Placement of Concrete. Once the Concrete Has Cured, the Cables Are Tensioned With the Use of a Mechanical Device. Thus Inducing Stress in the System 59
CONCRETE
(CONTINUED)
Cracking
Cosmetic = Shrinkage Cracks Structural = Differential Cracks 60
MASONRY (REINFORCED AND UNREINFORCED)
Components Of Construction Clay Brick Hollow Concrete Blocks Mortar 61
MASONRY (REINFORCED AND UNREINFORCED)
Properties Reinforced Masonry (RM) Steel Is Typically Added to Add Tensile Strength Unreinforced Masonry Does Not Utilize Internal Steel Reinforcing It Is Not Compatible With Seismic Regions Integrity Of Wall Contingent on Workmanship Specifically - Mortar Joints and Reinforcing Placement 62
MASONRY (REINFORCED AND UNREINFORCED)
Construction Of Masonry Wall Three or More Bricks End to End, for Five or Six Courses Vertically Then a Brick Is Placed at 90 Degrees (Header Course) To Tie Inside To Exterior Strength Of Mortar Bond Contingent on Mortar Design High Lime Content Provides Low Strength but Better Workability Low Lime Content Yields Higher Strength With Less Workability 63
BUILDING TYPES
Based On The Inherent Strengths And Weaknesses Of Specific Building Materials And Construction Methods, Each Specific Building Has Its Own Design Methodology And Integrity Concern.
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CATEGORIES
Wood Frame Buildings (W) Diagonally Braced Steel Frame Buildings (S2) Light Gauge Metal Buildings (S3) Concrete Frame Buildings (C1), (C3) Concrete Shearwall Buildings (C2) Precast Concrete Frame Buildings (PC2) Post Tensioned Lift Slabs Tilt Up Concrete Wall Panel Buildings (TU) Masonry Buildings (URM / RM) 65
WOOD FRAME (W)
Typically One To Four Stories In Height Classifications By Method Platform Balloon 66
WOOD FRAME (W)
(CONTINUED)
Principle Weakness Maybe In The Lateral Strength Of Walls Racked Openings Brittle First Story Failures Shifting Off Foundation Damage To The Masonry Fire 67
DIAGONALLY BRACED STEEL FRAME (S2)
One To Twenty Stories In Height Typically Non-Structural Exterior Covering Diagonal Members Providing Structural Stability 68
DIAGONALLY BRACED STEEL FRAME (S2)
(CONTINUED)
Principal Weaknesses Story Drift Shedding Brittle, Finish Materials Whipping Buckling (Compression) 69
LIGHT GAUGE METAL BUILDINGS (S3)
One Story Pre-Engineered Buildings Sheathed With Metal Siding and Roofing. Principal Weaknesses Loss of Sheathing = Loss of Structural Integrity Whipping Action “Weakest Link” Theory 70
CONCRETE FRAME BUILDINGS (C1) AND (C3)
Older Structural Frames Are From One To Thirteen Stories in Height Hazardous Configurations Soft First Stories (High, Open Framing) Open Front Structures (Typical Retail Structures of One and Two Stories) Corner "L" Shaped Structures Due to Torsion 71
CONCRETE FRAME BUILDINGS (C1) AND (C3)
(CONTINUED)
Principal Weaknesses Columns Break at Intersection With Floor Beams Severe Structural Cracking Weak Concrete and Poor Construction 72
CONCRETE SHEARWALL BUILDINGS (C2)
One to Thirteen Stories In Height With Structural Walls on All Four Sides "Punched Openings" for Doors and Windows.
Principal Weaknesses X- Cracking of Wall Sections Between Punched Openings.
Severe Cracking or Collapse of Columns May Occur in “Soft Stories” 73
PRECAST CONCRETE FRAME (PC2)
One to Ten Stories In Height Precast Wall Panels May Be Made for Taller Applications Typical Weaknesses Joint Failures Wall Panel Separation Progressive Collapse (Domino Effect) 74
POST-TENSIONED LIFT SLABS
Typically Three to Thirteen Stories in Height They Are Laterally Braced With Cast in Place Concrete Walls Slab Construction Typically 6" to 8" in Thickness Poured As a Pancake And Lifted Into Position 75
POST-TENSIONED LIFT SLABS
(CONTINUED)
Principal Weaknesses Changing Effects of Reinforcing Members During a Building Collapse Structures Become an Unreinforced System Due to the Above Condition 76
TILT UP CONCRETE WALL BUILDINGS (TU)
Usually One to Three Stories in Height Components Poured Concrete Wall Panels Wood Framing For Roof Structures Floors Concrete Floors Steel Framing With 1 1/2” Concrete Filled Deck Floors 77
TILT UP CONCRETE WALL BUILDINGS (TU)
(CONTINUED)
Principal Weaknesses Wall Separation Suspended Panels Fall Off Short Weak Columns Most Failures Are Limited to Exterior Walls 78
UNREINFORCED MASONRY BUILDINGS (URM)
Usually From One to Six Stories in Height Components Unreinforced Walls Wood Floors. Principal Weaknesses Inadequate Anchors for Parapets Weak Mortar Cause Split Walls Non-Load Bearing Walls Tend to Fail Earlier.
Lack of Interior Supports 79
ADVERSE STRUCTURAL LOADING
Earthquake Wind Explosion Fire Flood Bracing, Urban Decay And Overland 80
EARTHQUAKE
Lateral loads
Gravity weight
Vertical loads
81
WIND
Damage Elevation and Terrain Effects Velocity Partial Loss of Exterior Sheathing / Cladding Peeling off of Masonry Destructive Missiles 82
WIND
(CONTINUED)
Collapse Up Lift Pressures Roof or Wall Collapse Due to Loss of Lateral Support Tall Unsupported Walls Are Unstable Buckling or Bending of Light Metal Building “Closed” to “Open” Type Building 83
EXPLOSION
Conversion of Energy Shock Waves Terrorism 84
FIRE
Burn Through Material Distorted Steel Spalling Concrete 85
FLOOD
Pressure Hydrostatic Lateral Hydrostatic Lifting Pressure Damage Partly or Completely Move Buildings From Foundation Broken or Tilted Foundation Walls Undermined Foundations Impacted Objects 86
BRACING, URBAN DECAY AND OVERLOAD
Gravity Loading
Inadequate Materials
87
GENERAL COLLAPSE PATTERNS
Lean To Failure of a Single Bearing Wall Requires Stability of a Second Bearing Wall V-Shape Interior Support Fails Requires Stability of Two Exterior Walls More Common in Urban Decay / Overloaded Column Failure 88
GENERAL COLLAPSE PATTERNS
(CONTINUED)
A-Shape Exterior Supports Fail Requires Stability of Interior Column / Wall Pancake All Vertical Supporting Members Fail Floors Collapse on Top of Each Other 89
GENERAL COLLAPSE PATTERNS
(CONTINUED)
Cantilever Pancake With Extended Floors Most Dangerous Type of Collapse Overturn Failed Shearwall Foundation Failure 90
SURVIVABILITY PYRAMID
Spontaneous Rescue Community Response Emergency Service Providers USAR Task Forces 91
BASIC SEARCH AND RESCUE PLANNING
Stage I Recon Immediate Rescue of Surface Victims Scene Organization & Management Stage II Exploration & Rescue From Likely Survival Places Locating Victims Using the Hailing System Breaching & Shoring 92
SEARCH AND RESCUE PLANNING
(CONTINUED)
Stage III Selected Debris Removal Handling & Removing a Victim Stage IV General Debris Removal No Live Victims - Body Recovery 93
SEARCH AND RESCUE PLANNING
(CONTINUED)
Stage V Post Incident Debriefing Critique CISD 94
HAZARD CONTROL
General Hazard Reduction By Type Victim Access By Type Rescue Operations Checklist 95
GENERAL
Avoid Shore Remove Recognize 96
HAZARD REDUCTION BY TYPE
Light Frame Buildings Heavy Wall - URM Heavy Wall - TU & Low Rise Reinforced Masonry Heavy Floor Buildings Precast Buildings 97
VICTIM ACCESS BY TYPE
Light Frame Buildings Heavy Wall - URM Heavy Wall - TU & Low Rise Reinforced Masonry Heavy Floor Buildings Precast Buildings 98
INCIDENT DOCUMENTATION
Size Up Information Structure Type Occupancy Hazards Basic Safety Checklist 99
COURSE REVIEW
100