Building Collapse

The Wrong One!

OOOOps!

Definition

Deputy Chief (retired) Vincent Dunn defines a collapsing structure "as any portion of a burning structure that collapses due to fire damage."

Know what its made of and how it is constructed!

Building Construction Types

Reviewing the 5 typesExamining inherent hazards of each.

Type 1: Fire Resistive

made from non-combustible materials that do not add to the fire load

usually massive steel components that are encased in concrete

cast-in-place concrete, or the slabs may be poured off-site

most resistant to collapse.

Type 1: : Inherent Hazards

28 days to fully cure to a point that collapse is no longer a threat.

connection points have been the result of a catastrophic failure

Type1: Lack of cure time!

Type II Construction: Non/limited Combustible

: The structural steel is encased with a light fire-resistive coating

sheetrock or a sprayed-on coating . These structures employ a

lightweight parallel steel bar joist system that holds up a corrugated steel roof deck ( Timberlake HS Gym)

Type II Inherent Hazards

the materials that make up the roof covering a large amount of windows in the front wall

opening is spanned with a steel lintel that will support a free-standing parapet wall. If this lintel is compromised in any fashion, it can result in a complete failure of the parapet wall

employs a pre-cast wall slab that is tilted into place Each slab is braced with steel rods or rebar and insulated at the sides with each other

Type II

Type III Construction: Ordinary

use load bearing walls of masonry construction,

the roof and the floor can be made of wood.

can be either balloon frame or braced frame construction

Type III Inherent Hazards

older buildings may also have a parapet wall at the roof line, but with a twist: there may also be a cornice

25 feet will have an additional steel I-beam support called a channel rail

Spreader plates, in the shape of stars, plates, or channel sections

but beware the spreader plates that are irregular in placement

Down Town Spirit Lake

Type IV Construction: Heavy Timber

Exterior walls are brick or other type of masonry,

the columns being a minimum of eight inches by eight inches

used to house commercial occupancies originally

the second-most resistant to collapse.

Type IV Inherent Hazards

buildings more resistant to collapse neglect, shoddy renovations, and

weak connection points can cause complete failure

These trusses can be parallel chord or bowstring

Type IV Inherent Hazards

Type V Construction: Wood Frame

walls, floors, roofs, and other structural members are made up entirely of wood

Braced frame Balloon frame Platform frame

Braced Frame

Braced frames resist gravity load in bending and axial compression, and lateral load in axial compression and tension by triangulation, much like trusses

Balloon Framing

Platform Framing

Type V Inherent Hazards

are all wood . Two-by-four studs may in fact be

holding up an entire upper floor, with no built-in compensation supports

many of these structures have a veneer wall, made of decorative masonry materials

are attached to the wood wall, placing an eccentric load on the wall

Type V Inherent Hazards

Lightweight construction components, such as trusses, truss joist I-beams (TJIs) and Oriented Strand Board (OSB)

larger square footage, but are being constructed with half of the materials that were used in the past

TJI (Trus Joist developed the wooden I-joist 50 years ago)

Trusses

Collapse Patterns Lean-to Floor Collapse: 

the roof or floor supports fail on one side of the structure, and the opposite side of the floor is still connected

V-shape Floor Collapse

lower walls or floor joists fail, due to heavy loads located in the center of the floor.

two voids, one near each exterior wall.

V-shape Floor Collapse

Pancake Floor Collapse

dropping the floors and the roof on top of each other

Voids will be created between the floors

Pancake Floor Collapse

Cantilever Floor Collapse

collapse occurs when one or more walls have failed

other end of the floor is still attached to the other bearing wall.

the most dangerous type of collapse to operate in

adequate shoring must be in place before operations can commence.

Cantilever Floor Collapse

A-frame (Tent) Floor Collapse:

the flooring separates from the exterior bearing walls, but still is supported by one or more interior walls

90-degree (Full Wall) Collapse

entire wall falls out as one unit, falling outward

Masonry walls collapse more commonly in this fashion

V structures with veneer walls can fall victim to this collapse as well.

90-degree (Full Wall) Collapse

https://www.youtube.com/watch?v=Mntm4SdIayQBuild

(Waterloo Iowa)

Curtian Fall Wall Collapse: a masonry wall falls almost straight downward Curtains https://video.search.yahoo.com/video/

play;_ylt=AwrTHQh8UqxUmjEAVhtXNyoA;_ylu=X3oDMTB0Njd0NGhwBHNlYwNzYwRjb2xvA2dxMQR2dGlkA1NNRTgwN18x?p=fire+building+collapse+youtube&tnr=21&vid=C67B7817CA1695027F9CC67B7817CA1695027F9C&l=29&turl=http%3A%2F%2Fts2.mm.bing.net%2Fth%3Fid%3DUN.608005844396607849%26pid%3D15.1&rurl=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DjNtnj-J0UtY&sigr=11ahobk0t&tt=b&tit=NEW+YORK+BUILDING+COLLAPSES+AFTER+FIRE!&sigt=117s9r4i9&back=https%3A%2F%2Fsearch.yahoo.com%2Fsearch%3Fp%3Dfire%2Bbuilding%2Bcollapse%2Byou%2Btube%26type%3D2button%26fr%3Dymyy-t-999%26ei%3DUTF-8&sigb=135ndp5f6

Inward-Outward Wall Collapse:

the wall literally breaks in two, with the bottom section of the wall falling outward, and the top floors falling inward

Braced frame buildings are known to fail in this fashion. This type of collapse occurs more commonly in wood frame buildings, many times without warning.

Inward-Outward Wall Collapse:

Iight my fire Religious reporter Top IQ contestants

Wrap Up

What are the 5 types of construction?

What type possess the least collapse risk?

What is critical about a cantilever collapse?

If we have a fire on main street how much protection are do we need if we have a 90 degree full wall collapse?