PN302 Collapsed Structures Flashcards
What are the NATURAL causes of collapse?
- Earthquake
- Hurricane
- Lightning
- Flooding
- Subsidence
What are the HUMAN causes of collapse?
- Premises is under renovation
- Accidental impact
- Arson
- Terrorism induced (vehicular impact, explosion)
- Accidental gas explosion
What are the elements of structure?
- Beam: spans an opening,can withstand load placed upon it
- Column: carries weight via compressive force to elements below
- Floor: divides building, helps Support walls
- Wall: load bearing or not, separates area and provides shelter
- Protected Shaft: enclosed space between floors, increased strength and fire resistance
- Gallery: floor spanning high ceiling room, adds space and helps support high wall
What are the types of construction?
- Framed: typically steel or reinforced concrete, frame bears load. Commonly modern buildings, greater resistance to collapse
- Unframed: walls will be load bearing, also referred
to traditional or masonry construction. If load bearing walls columns or beams fail, result is extensive
collapse and large area of debris
What are the 3 categories of collapse?
- Internal
- External
- Total
Name the 4 types of Internal collapse
- Pancake: failure of load bearing walls or an upper floor. One collapse causes subsequent collapses via shock loading.
- Lean to: where a supporting wall fails
and a beam fails at one end, forming triangle shaped void - V: floor fails in centre, but not at ends
- Tent: floor beams fail near outer walls but remain supported in centre
Name the 3 types of external collapse
- 90° collapse: MOST DANGEROUS - wall falls outward for a distance at least equal to its height
- Curtain: Part of the wall comes straight down, debris piles up near base.
- Inward/Outward: horizontal crack in middle outward causes one section to collapse inward, one outward
Who should the OIC request at any dangerous structure / collapse?
Dangerous Structures Engineer.
Pending the arrival of a Dangerous Structures Engineer, what control ,ensures can be implemented?
Cordoning off an area by the erection of barriers
Depending on the scale and causes of collapse, what procedures may need to be instigated by the IC?
- Major Incident procedure
- Terrorist related Incidents
- HAZMATS
- Civil Disturbance
- Fires involving Radiation
Why is scene preservation an important consideration?
The majority of collapses will be subject to an investigation by the Police and HSE
What unusual pressures, particularly in the early stages of the incident, may crews face?
Extreme Pressure to act through public expectation
Why is it important to remove Good Samaritans from the scene as quickly as possible?
Any remaining parts of the structure may be structurally unsafe, and uncoordinated actions by non emergency service personnel could lead to further collapse
What hazards may be encountered at collapsed structure incidents?
- Obstructed/restricted access
- Restricted visibility (smoke,dust)
- Unstable underfoot conditions
- Falling objects
- Overhanging hazards
- Airborne particulates/irrespirable atmosphere
- Secondary collapse
- Weight and position of casualties
- Bulk and weight of debris
- Explosive / flammable atmosphere
- Poor lighting
- Biological hazards
- Exposed / damaged utilities
- Asbestos
- Sharp/protruding objects
- Further acts of terror (if this was the initial cause)
What would the OIC consider requesting and providing at an early stage of the incident?
Request:
- USAR tactical advisor (UA)
- Dangerous Structures Engineer
Provide:
- RVP
- Dedicated USAR RVP if required
