1. Collapse Patterns

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3. Collapse Patterns Lean-to collapse V-shape collapse Pancake collapse
Cantilever collapse

4. Collapse Patterns
Lean-To V-Shape
Pancake Cantilever

5. Lean-To Floor Collapse

6. V-Shape Floor Collapse

7. Cantilever Collapse

9. Pancake Collapse

12. Condition of Voids
Different void types will have significant impact on victims and their accessibility
Victims do not survive well in tightly compacted collapse areas consisting of masonry rubble, or broken concrete
Open survivable voids are often found under wooden floor panels that collapse into angular, interlocking planes
Survivable voids have been found under concrete structures where floors have projecting beam elements that hold slabs apart
Partially collapse structures may have large triangular voids

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14. General Types of Building Construction Hazards
Light Frame
Heavy Wall Construction
Heavy Floor Construction
Precast Construction

16. Light Frame Hazards Weakened wall and connections Broken utilities
Combustible materials
Cracked or leaning walls
Separation from foundations
Cracked or leaning chimneys or veneer walls
Separated porch or upper story connections
Loose roof tiles or roof equipment
Broken glass and damaged door frames

17. Light Frame Access Considerations
Horizontal entry through existing cavities
Breaching through walls
Vertical access through floor/roof from top down
Remove/shore hazards as required

19. BRICK PATTERN THAT
IDENTIFIES UNREINFORCED
MASONRY. HAS BOND
(HEADER) ROW AT
ABOUT EVERY SIX
ROWS. AT FRONTS
OF BUILDINGS, THE
PATTERN MAY BE
HIDDEN BY FANCY
MASONRY VENEER

20. Heavy Wall Hazards Broken utilities
Weakened perimeter load bearing walls and connection to floor and roofs
Broken parapets, chimneys, ornamental masonry
Broken walls and columns
Broken structural connections
Cracked wall corners, windows, door frames
Unsupported collapsed floors
Loose HVAC or roof equipment

21. Heavy Wall Access Considerations
Horizontal entry through existing openings
Vertical access through floor/roof from above
Hand removal of bricks may be required
Large pieces of wall may be removed by clamshell bucket on crane or excavator

23. Tilt-Up Hazards Broken utilities
Separation of walls and roof, leading to partial collapse of either or both
Collapse of walls or roof
Falling roof beams, ceilings, non-structural items

24. Tilt-Up Access Considerations
Horizontal entry through existing openings
Vertical access through roof/floor
Cut holes in wall panels 2 feet minimum from joints
Remove wall panels and large roof sections by crane

26. Heavy Floor Hazards
Weakened columns and poor connections between floors and columns
Broken utilities
“Empty cage” – concrete column failure
Broken structural connections
Diagonal shear cracking in support beams
Broken infill or shear walls
Loose HVAC or roof equipment

27. Heavy Floor Access Considerations
Find any existing vertical access shaft
Preferred access made by cutting through slabs from above victim/collapse
Cut non-bearing or infill walls after proper assessment
Remove large pieces after all connecting rebar's have been cut

29. Precast Construction Hazards
Weakened interconnection of structural components – floors, wall panels and beams
Broken utilities
Broken walls, cracked corbels at beam-to-column connections
Cracked columns at top and bottom joints
Broken wall panels
Loose HVAC or roof equipment

30. Precast Access Considerations
Cut through thinner horizontal sections for vertical access from above
Carefully remove larger covering pieces with crane
Horizontal entry through existing cavities
Cut through wall panels 2 feet minimum from joints