Flashcards in Ch. 14 Non-Fire Bldg Collapse Deck (45):
Causes of NONfire building collapse.
Two broad categories:
For some no warning:
For others can be anticipated (w/o specific location):
Earthquakes and explosions
Tornadoes and hurricanes
When confronted by partially collapsed bldg, FF's must assume remaining building _________.
Can be seriously weakened (NOT rest will collapse)
Non-fire bldg collapse causes (6)
Poor construction methods.
Concerns common to collapse/partial collapse (7)
RUPTURE of gas distribution mains (only "rupture").
Loss of LANDLINE communication.
*Utilities/roads for DAYS/EVEN WEEKS.*
Multiple bldg collapses.
Fires following event.
Impairment of bldg life safety systems.
Fires when utilities restored
Areas for earthquakes p. 394
West coast, including *ALASKA* and Hawaii PARTICULARLY vulnerable
Earthquakes, buildings more at risk for partial/total collapse than newer buildings
Built prior to 1930s
Factors that contribute to extent of building damage and potential collapse during earthquakes (2)
LOCATION of bldg relative to responsible fault and epicenter of earthquake.
SOIL conditions beneath bldg, especially potential for liquefaction of loose, sandy soil
Seismic design consideration
Critical buildings have higher requirements. Critical are: (3)
Other important public uses
Earthquakes will likely be followed by ________, some of which may be ____________ as the original.
NEARLY as strong
Potential for landslides occurs _________. Although potential for landslide more likely during _____, they may occur ______.
Heavy rains or in conjunction with earthquakes.
Forewarning/early warning signs of landslides (3)
Damage to underground utilities.
Cracking in roads.
Minor slides in area.
On hillsides prone to landslide, addition of ________________can be the trigger to a major landslide.
Groundwater through landscape watering OR
Broken water main
There are ____ specific model bldg code requirements to address LANDSLIDES. Environmental reports should _______ this issue and zoning regulations typically _______ it.
*fire service working with public works*
_____ is sinking or settling of land due to various natural and human-caused factors, such as removal of _____.
Subsidence (form of GRADUAL sinking).
Underground water or oil
Primary cause of subsidence in U.S. is ________________.
Removal of large amounts of underground WATER
**Definition=water OR oil, PRIMARY=water**
Occurred in ______. Due to pumping oil in ____________.
Gradual AND more or less uniform when cause is removal of _______________.
Almost every state.
California, Louisiana, and Texas.
Underground liqUid (more or less Uniform)
_______ is a natural depression in a land surface formed by the collapse of a cavern roof. Generally occurs in _________ regions. This type of failure represents an ___________ of subsidence.
*cavern/cavity = sinkhole*
Like landslides, sinkholes are _________. Collapse of ground surface into cavity. Cavity are usually created by __________.
Interaction of groundwater with rock formations that are water soluble.
*subsidence=gradual. landslide and sinkhole=usually sudden*
Sinkholes can occur over areas that have been ____________ or more commonly in urban areas as the result of ________.
Subjected to underground mining.
Water main breaks
Determining potential for subsidence and sinkholes is often done by ____________.
Examining historical records.
_______, especially those associated with _____ and ______, often result in catastrophic regional events.
In wind-borne debris regions, such as coastal areas subject to hurricanes where the basic wind speed is _______, window glazing is required to be impact-resistant. Residents may also employ special brackets, known as _____________, to provide additional reinforcement as storms approach.
110 mph or greater.
Building collapse can occur due to force associated with accumulated _____, _____ or both. These type of collapses can happen ________ and are usually ________.
Without warning and isolated events
Another cause of bldg collapse is from ______. ______ can be simply described as water flowing where it is not normally expected.
Damage from floods occurs in several ways: (2)
Water undermines the foundation, causing partial/total collapse.
House swept off of foundation, deposited in whole or part hundreds of feet from where it originally rested.
_____ are another required aspect of structural design considerations for a new building. Requirements vary depending whether or not building is also subject to ___________.
High-velocity wave action
Foundation and structures are required to resist ____, ____, and _____.
Flotation, collapse, lateral movement
Structural design, including calculations, is typically reviewed during the plan review process ______ construction begins. Occasionally an ________ will slip through or there will be _________ that negatively impacts the integrity of design, resulting in partial or total collapse.
A field change
Poor or careless construction methods: (4)
(WITS end trying to figure this out)
TEMPORARY loads-temporary loads exceed final design loads.
SEQUENCING-improper sequencing of construction process.
WEAKNESS of building frame-temporary weakness, applies to POURED in place (not cast).
INSTABILITY of building frame-until final members in place, vulnerable to vertical and horizontal loads-temporary bracing
Common means of demolition (2)
Piecemeal demolition-performing using hand tools or machines AND
*BOTH require well thought out plan*
4 means of controlled collapse
Crane with demolition ball.
Hydraulic pushed arms.
Wire rope pulling.
A primary GOAL of the demolition process must be:
To protect nearby structures
When removing PRIMARY structural members, there is _____ the potential for ________.
An unexpected collapse will likely involve ________ because it is likely to occur when building is occupied by workers involved in demo.
Well planned and executed controlled collapse should result in _________ at the ground to be ___________. Rescue ________ be an issue.
A pile of debris.
Rising concern with vacant bldgs are:
Problems with vandalism and scavenging
_______ is being accelerated by increased price of wood and metal.
May result in weakening of structure or even UNWANTED building collapse
*Never WANT an amateur working with you*
During building demolition may also lead to an UNEXPECTED collapse.
Often, accidental explosions are the result of:
Natural gas leaks within a building
Common sources of explosions (BGDFM)
Finely powdered dust.
Storage of fireworks/blasting agents.
Methamphetamine laboratories (today's society)
Deliberate USE of EXPLOSIVES
*use - youse guys*