Ch 22 pg 555-562 Building Collapse Response Guidelines

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Why is it necessary for ground-level forces to withdraw to a specific distance from a wall in a bowstring truss described in the content?

To ensure the safety of other responders.

To maintain a tactical position against potential adversaries.

To avoid less obvious threats from nearby objects.

Bowstring truss construction has a collapse radius that is larger due to explosive force (correct)

What alternative strategies are suggested if responders cannot maintain a safe distance from a threatening wall?

Call for additional reinforcements to secure the area.

Set up defensive positions within the immediate vicinity.

Engage in a frontal assault on the wall.

Establish flanking positions or utilize an elevating platform. (correct)

What potential danger should firefighters be cautious of when moving out of one collapse zone to another?

The collapse zone of intersecting sidewalls. (correct)

Exposed electrical wiring from nearby lines.

The chance of encountering hostile individuals.

Falling debris from adjacent buildings only.

What is a risk associated with using an elevating platform during a fire-related incident?

Being positioned directly over a collapsing roof. Signup and view all the answers

According to the safety measures discussed, how tall could the fireball be during a roof collapse?

50-60 feet high. Signup and view all the answers

In which types of buildings are V-shaped collapses most likely to occur?

Class 3 and 5 buildings with wooden floor joists Signup and view all the answers

What is the likely consequence for victims situated directly below a V-shaped collapse?

They have the least chance of survival. Signup and view all the answers

What characteristic is typically associated with the void spaces created by V-shaped collapses?

Two voids are present on the sides of the debris. Signup and view all the answers

Which of the following scenarios can lead to a V-shaped collapse occurring?

Overloading of wooden floor joists or removal of center support. Signup and view all the answers

In the context of V-shaped collapses, where are victims likely to be thrown during the collapse?

Toward the center of the building along with loose debris. Signup and view all the answers

What characteristic defines an A-frame collapse?

The structure collapses inwards to form a tent-like shape due to a strong central support. Signup and view all the answers

In an A-frame collapse caused by an explosion, where are the void areas most likely to be found?

Close to the remaining central obstruction, such as a bearing wall. Signup and view all the answers

How does the pressure from an explosion affect the structure during an A-frame collapse?

It equalizes within the structure while pushing out exterior walls. Signup and view all the answers

Which conclusion can be drawn about survival rates in A-frame collapses compared to V-shaped collapses?

Survivors in A-frame collapses are more likely to be around central supports than those in V-shaped collapses. Signup and view all the answers

What is the primary reason pancake collapses are not considered inherently unstable?

Floors often rest on the floor below them. Signup and view all the answers

In assessing a pancake collapse, which aspect is most critical to determine safety?

How the load is being transferred to the ground Signup and view all the answers

What role do strong objects play in survival situations during pancake collapses?

They can serve as points of rescue. Signup and view all the answers

What is the primary cause of a supported lean-to collapse?

The failure of the support at one end of a floor or roof. Signup and view all the answers

What happens to the floor or roof when one bearing wall fails?

The floor will drop at the end where the wall has failed. Signup and view all the answers

Which building classes are specifically mentioned as having made rescues from pancake collapses?

Class 3 and Class 5 Signup and view all the answers

What aspect of pancake collapses must responders carefully examine for a complete assessment?

The condition of the lowest level Signup and view all the answers

Where are people most likely to find large voids after a lean-to collapse?

Near the supporting walls that remain intact. Signup and view all the answers

What specific group has the lowest chance of survival during a lean-to collapse?

Those on the falling floor. Signup and view all the answers

In a lean-to collapse scenario, what is likely to happen to objects on the floor above?

They will be thrown into a heap at the low end of the slope. Signup and view all the answers

What occurs during an unsupported lean-to collapse?

Floor or roof joists hang in midair, held only by one wall. Signup and view all the answers

Which scenario represents a supported lean-to void?

The right side of the joists remains partly attached while the left side falls. Signup and view all the answers

What is a critical safety measure while operating under overhanging debris?

Carefully monitor the area and pull down debris if necessary. Signup and view all the answers

What should be done before pulling down overhanging debris?

Remove surface victims and search voids for survivors. Signup and view all the answers

What is the condition of the low end of a supported lean-to that poses severe danger?

It is totally unsupported, risking further collapse. Signup and view all the answers

What is a defining characteristic of individual voids in a collapse?

They occur randomly depending on structural layout. Signup and view all the answers

In what scenario is locating victims considered simpler during a collapse?

During pancake collapses with floors maintaining their relationship. Signup and view all the answers

What types of objects may contribute to the formation of individual voids?

Strong objects like refrigerators and washing machines. Signup and view all the answers

What challenge arises when attempting to locate individual voids?

Their presence depends on the random arrangement of structures. Signup and view all the answers

What can sometimes be a possibility regarding movement within individual voids?

Crawling may be possible if the void is sufficiently large. Signup and view all the answers

Study Notes

Safety Protocols Around Potential Collapses

Maintain a distance of at least 2.5 times the wall height from structures that could suddenly collapse.
In narrow streets or tight spaces, consider flanking positions or utilize elevating platforms for safety.
Be aware of secondary threats like trees, poles, and power lines in the area during a collapse.
Elevated positions pose risks, including potential fireball eruptions from falling roofs; avoid being directly above the collapse area.

Types of Collapses

Five recognized collapse types:
- V-shape
- A-frame
- Supported lean-to
- Unsupported lean-to (cantilever)
- Pancake

V-shaped Collapses

Common in Class 3 or 5 buildings with wooden joists under load or compromised structure.
The center portion collapses while exterior walls remain standing, creating two voids on the sides.
Survivors are often found near the edges, while those beneath the collapse have the least chance of survival.

A-frame Collapses

Occur when a strong central support maintains the structure, causing outer ends to fall.
Frequently result from explosions; voids are near the central supporting structures.
Survivors are more likely to be found near the center support rather than the edges.

Supported Lean-to Collapses

Triggered by failure at one end of a support structure, creating a sloping design.
Objects above will accumulate at the lowered end, presenting potential survival opportunities for those nearby.
Seek voids along remaining walls for enhanced chances of finding survivors.

Unsupported Lean-to Collapses

Feature dangling joists held by a standing wall, leading to risks of further collapse.
Extreme caution needed when searching beneath unsupported areas; may require removal of debris post-survivor search to ensure safety.

Pancake Collapses

Floors drop in layers, resembling stacked pancakes, and often rest securely on the lower levels.
Investigate the lowest level to assess load transfer and stability, avoiding further collapse into lower areas.
Rescues are feasible in Class 3 and 5 buildings if strong nearby objects are intact.

Individual Voids

Created by strong objects that remain standing during a collapse, leading to random spaces.
More difficult to locate due to their irregular occurrence based on furniture and layout.
Victims in pancake collapses are easier to find since layers typically maintain their structure and position.

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Description

This quiz covers key safety measures when responding to potential building collapses, particularly regarding defensive positioning away from walls. Understanding the importance of distance relative to wall height is crucial for responders, especially in urban environments where space may be limited. Test your knowledge on these critical safety protocols.