Structural Collapse

What is the minimum amount of water that seasoned wood can contain?

10%

What is the minimum spacing between anchors?

12 times the diameter of the anchor

In an oxygen/acetylene torch system, acetylene becomes unstable when compressed in a gaseous state about..

15 psig (pounds per square inch gauge)

What is the average weight of reinforced concrete?

150 lb /cu ft

What nails reduce splitting of wood?

16d coated

Has-powered tools predominantly use what type of engine

2-cycle engine

Keep the length to width ratio (L/D of wood post to less than

25

Cribbing generally has what load capacity per contact point?

500 psi (pounds per square inch)

At what temperature does steel begin to lose its strength?

700 F (371 C)

When collapse patterns is formed when the flooring separates from the exterior bearing walls but is still supported by in terror bearing walls or non-bearing partitions?

A-frame

Consideration for your individual health during mobilization include...

Adequate prescription of drugs, appropriate PPE on hand, Pre-deployment physical exam, extra glasses/contact lense

When is a site re-prioritized for search and rescue operations?

After the initial search

What do General Respiratory Problems in US&R include?

Airway obstruction (patients with high-grade obstructions have a higher risk of early mortality in the US&R environment) Inhalation Injuries

Considerations for packaging should begin when?

Before the protective system is designed and removal in mind

Which two principles clarify reporting relationships and eliminate confusion caused by multiple, conflicting directives?

Chain of command, Unity of command

What system usually have traveling pulleys that move in the opposite direction of the load. These systems are less commonly used by rescuers

Complex system

What system is when o e simple system pulls on another simple system and some of the traveling pulleys move at a different speed than the load

Compound system

Which building material is strong with respect to compression but weak in terms of tension and shear?

Concrete

Which building type commonly experiences the following problems? •X-cracking of wall sections between openings •Severe cracking of shallow wall/floor header sections that frame between solid wall sections

Concrete shear wall buildings

What can occur to concrete as the result of extreme changes in temperature or tension stresses when exposed to extreme forces?

Cracking

What are examples of a class 1 lever?

Crowbars, wrecking bars, pliers, and scissors

What are common atmospheric problems within a confined space?

Decreased oxygen concentrations, presence of CO, presence of hydrogen sulfide

Vomiting, blood loss, edema, and burns are all potential causes of

Dehydration

A successful search requires that victims be _____ and then _____

Detected; located

A risk/benefit assessment first involves:

Determining the potential number of trapped victims

How to you calculate the load angel factors

Divide the strap length by the height from the top of the object straight up to the hook (L / H)

What precast concrete shapes are difficult to shore?

Double-T Single-T

unreinforced concrete structures perform poorly in...

Earthquakes due to their tendency to break into large pieces

What heat-related condition are TF members most likely to experience?

Exertion heat stroke

What are negative effects of fire on steel structures?

Expansion Loss of structural rigidity Loss of strength

Which of the following can be attached to concrete using an expansion anchor, concrete screw, or through bolt?

Eye nut Swivel hoist ring

What are three types of hazards that can be identified in damaged, partially collapsed structures?

Falling Collapse Hazmats

The primary hazards of a tilt-up heavy way collapse are

Fire, if building has wood floors or roof Walk will fall a distance equal to its height, away from the base

I'm shear wall or box buildings, what elements act like giant beams as stresses in tension and compression are generated at the edges and shear stresses are distributed throughout the plane?

Floor and roof planes

The amount of friction between objects depends on

Force of gravity Roughness if the contact surfaces Type of surfaces in contact

lateral loads include

Forces pushing against a structure

What type of nail is preferred for shoring systems?

Full head nails

What are vertical loads?

Gravity, dead loads from building components, live loads from furniture, people, or moveable partition and impact loads

When shoring component is used to hold various joints together but is not designed to support any direct load?

Gusset plate

A shoring system collects a load at the roof through its

Header

What building type tends to exhibit partial collapse due to the bearing walls falling away from the floors?

Heavy wall

A small outside force or effort at the _____ _______ on the object can change its condition from static to unstable equilibrium

Highest point

What vertical load-resisting system normally bends when loaded?

Horizontal beams and joist

Sudden collapse can occur due to gravity loading when a vertical support is:

Inadequate Overloaded Reduced in capacity

The process of setting serves to

Keep blades and chains cool and lubricated Reduce the amount of dust

What vertical shore has space inside that can be used as a safe haven?

Laced post shore

A multistory frame building with a kea ing first story need what type of shoring

Lateral / diagonal shoring

In light-frame buildings, additional collapse is unlikely in structures containing how many floors?

Less than 3

What construction type tends to be highly engineered with little redundancy or reinforcement and is very flexible?

Light metal

The principle of lighting safety is to:

Limit the amount of electrical energy introduced into a hazardous area under normal conditions

In a windstorm, the weight of the building is helpful in resisting uplift but has __________ effect of wind forces

Little

The relationship between the weight of a load being lifted and the power of the force required to lift, push, or hold that load is called

Mechanical Advantage (MA)

During the risk/benefit assessment, who is ultimately responsible for determining the feasibility of extracting victims in high-risk environments?

Medical Team Manager(MTM) in consultation with the Task Force Leader(TFL) or Rescue Team Manager(RTM) and Structures Specialist(StS)

What construction type depends on how well the structures are attached to their bases and how well the bases are connected to the ground or foundation

Mobile homes

Portand cement, water, sand, and lime are combined to form what substance?

Mortar

Post-extrication medical deterioration and death due to crush injury are....

Often preventable

In a URM collapse, where are badly injured or dead victims most often located?

Outside, and adjacent to walls

The use of stitch drills allows the concrete to be

Placed in shear or tension when applying a breaker

crush syndrome, three cell contents that can be released to the body are

Potassium, myoglobin, and purines

What are the three general parts of an electric tool system?

Power generation, transmission, and tool

Shoring should be constructed upward from the foundation in which type of structure?

Precast concrete

Rebar and heavy wire are often added to masonry structures in order to

Provide tension and shear resistance

What simple machine is used to change the direction of efforts?

Pulley

In the absence of a SO, who should conduct the safety briefing?

RTM or appointed RSO

What is used to deliver shear forces from the diagonal component of a sloped raked into the wall plate and solo plate

Raker cleat

What respiratory protection systems has a longer working time than an SCBA and protects against contamination and O2 deficiency?

SABA

Which type of force tends to change the shape of an object from a square to a parallelogram?

Shear

What element of a light-frame building is designed to resist lateral loads?

Sheathing

What system is when one rope is routed between pulleys on the anchor and load. All of the moving pulleys do so at the same speed and in the Sam e direction as the load.

Simple System

What type of anchor can be safely used in hollow concrete block?

Sleeve anchor

The loss of surface material when concrete is subjected heat or the force of breaking and breaching is called

Spalling

What shire is built when access to the base of the wall is obstructed?

Split some raker

What construction type is designed with the ends of the ends of the beams being rigidly joined to the columns so that the buildings can resist lateral wind and earthquake force without the assistance of additional braces or walls?

Steel moment frame

The purpose of placing rebar in co Crete systems is to:

Strengthen and stabilize the concrete in tension

What type of vertical shore is used to initially stabilize-damaged floors, ceilings, or roofs so that the more substantial shoring can be constructed at less risk?

T-Spot shore

Which forces are applied through an object at 180 degrees to each other, usually along the long axis?

Tension Force

What type of crack occurs as a result of bending of the slab or beam?

Tension crack

When considering the amount of instability when selecting shoring, the general rule for a building out of plumb is

The lateral load is 1% of the building weight for every 1% it is out of plumb

A load will tip over when lifted if

The load is lifted below its CG

What is an object's CG?

The point which the object's mass in evenly distributed

The magnitude of an earthquake determines

The potential number of affected structures

What type of building tends to be brittle with little capacity to resist unanticipated loads, but also has numerous interior walls that may prevent floor collapse in multistory buildings?

URM buildings

To reduce risk of further inhalation injury to a victim, you should...

Ventilate the confine space Place a dust mask on the patient

What events can contribute to a secondary collapse?

Vibrations, water shifting debris pile, and weakened walls, floors, columns or beams

How does wood serves as a warning mechanism of an impending collapse?

Wood fails slowly and does so noisily

What metals can a torch cut?

Wrought iron and steel

What is Portland Cement?

a hydraulic cement made from a finely ground mixture of limestone and clay.

Define bending

combination of tension, compression, and shear forces through an object

Pneumatic tools are powered by:

compressed air

The CG of a solid object is located in three planes or directions which are

• X axis = horizontal axis, side to side • Y axis = vertical axis • Z axis = horizontal axis, front to back

Four functions need to be addressed before any load is stabilized, lifted, or moves

•CG •Load stability •Estimated load weight •Lifting functions, including critical angle considerations

What patient conditions tend to have a higher risk of early mortality in the US&R environment?

•High-grade obstructions •Prolonged, limited chest wall expansion

What is low risk levels

•pancake concert slabs •soft first-story collapse •wood one-and two-story structures

What is medium risk level

•partly collapsed concrete •racked wood building of theee or more stories •free-standing unreinforced masonry/ concrete walls out of plumb •URM with lean-to, V, or walk-fall collapse

What is high risk level

•partly collapsed precast or post tension concrete • I'm-collapsed, leaning elements •free-standing URM/ concrete walls that are leaning •many falling hazards