Ch 22 Structural Collapse Flashcards
Buildings that show the greatest resistance to collapse are what? Pg 544
Class 1 fireproof construction. Those buildings have fire resistance ratings of up to 4 hours.
Second best construction type, as far as resistance to collapse is concerned is what? Pg 545
Heavy timber. These buildings are generally quite stable due to the size of their load bearing members, which are generally 12x12 wooden columns and brick walls.
The collapse danger zone should be at least what? Pg 545
1 1/2 times the height of the wall
The third most collapse resistant building is that of what? Pg 546
Class 3 ordinary construction
The fourth category in order of resistance to collapse is what? Pg 546
Class 5
Which class construction is the least resistant to collapse? Pg 547
Class 2
A 100 foot long I-beam heated uniformly to how many degrees and will expand to how many inches? Pg 547
1000 degrees and 9 1/2 inches lengthwise.
Those with protected steel or concrete supporting system resist total collapse rather well this is called what? Pg 547
Framed structures, since most of their weight is carried in the Frame skeleton.
Building that is built so that most of the weight rests on bearing wall and consist of wood frame, brick and joist, heavy timber are called what? Pg 547
Unframed buildings
The hierarchy of structural components is as follows, ranging from most important to least important? Pg 548
- Bearing Walls
- Columns
- Girders (which support beams)
- Beams and joists
- Floor or roof decking
Wooden structural elements burn through at a rate of what? Pg 549
1 inch for every 45 minutes of open burning time
Lightweight steel bar joist can lose their strength is as little as how many minutes of fire exposure? Pg 549
5-10 minutes
A 1,000 gpm master stream adds approximately how many lbs to the building each minute? Pg 551
8500 lbs
There are five generally recognized types of collapse? Pg 559
- V-shape
- A-frame
- Supported lean-to
- Unsupported lean to, also called cantilever.
- Pancake
V-shaped collapses usually occur in what class buildings having wooden floor joist when these joists at either overloaded, have a center support removed, or are burned away under load? Pg 559
Class 3 or 5
What type of collapse results when a strong center object hold up the center portion of a structure, while the outer ends of floors or roof fall, resulting in a tent like structure in the center of the debris pile? Pg 560
A-frame
Which collapse results from the failure of the support at one end of a floor or roof? Pg 560
Supported lean to collapse
Which collapse result from similar events that cause the supported lean to, but the floor or roof joist end up dangling in midair, held only by their attachment at the remaining standing wall? Pg 560
Unsupported lean to
What type of collapse are often the deadliest, since the floors tend to fall nearly straight down, stacking up like a stack of pancakes? Pg 561
Pancake
Result from spaces formed by a series of strong objects that prevent collapse into that particular area and may be found in any type of collapse? Pg 562
Individual voids
The five stages of the collapse rescue plan are as follows? Pg 564
- Reconnaissance and size up
- Accounting for and removal of the surface victims.
- Searching voids
- Selected debris removal and tunneling.
- General debris removal
You should only begin to remove what after you have completed the first four stages and removed all victims that can be located using those procedures, have conducted a thorough search using search dogs or acoustic and seismic devices, and are certain that there are no other survivors? Pg 568
General debris
What should the minimum collapse zone be established at when there is a bowstring truss roof with hip rafters
resting on the ends of the truss?
p. 558
2 1/2-times the height of the wall
What is the first step that should be taken when a collapse has occurred and there are trapped victims? p. 564
Reconnaissance and size-up
Where does most of the weight of the building rest in an unframed building?
p. 547
Bearing walls
What is the first priority for the first-alarm engine companies? Pg 569
Fire burning in the rubble pile
How much does a masonry wall weigh per cubic foot? p. 556
80-130 pounds
What is considered the second best construction type as far as resistance to collapse is concerned? p. 545
Class 4
Which is the second most serious possible warning sign of collapse?
Truss construction
What is the usual way to initiate a withdrawal from the building? p. 555
Portable radio
What is the minimum distance in every direction from the operations that crowds should be kept away when using a seismic or acoustic device to locate trapped victims after
a collapse? p. 568
One block
In what time span do wooden structural members tend to burn through 1 inch? p. 549
45 minutes
Which direction does the top of the wall often fall when a wall collapses?
p. 557
Outward
Which level of the pancake collapse should be inspected to determine if the load is being safely transferred to the ground? p. 561
Lowest level
Which would be a better choice if you must cut a piece of flooring in an unstable building? p. 562
Circular saw
What minimum number of members on the search team should be an EMT when searching for a trapped firefighter after a collapse?
p. 563
One
What should be deployed so that once the trapped firefighter has been located a back-up team can come to
the location? p. 563
Search rope
