NEBOSH CC Excavation and Demolition Safety 2

Question 1

What is the minimum distance from the edge of an excavation that heavy plant and materials should be kept to prevent surcharge loading causing collapse?

Accepted Answer

Materials and plant should be kept as far back as practicable; a common guideline is at least equal to the depth of the excavation

Answer

30 cm from the edge

Answer

There is no minimum distance

Answer

1 metre regardless of depth

Question 2

What protective measures should be in place around an open excavation to prevent people and vehicles from falling in?

Accepted Answer

Substantial barriers or guardrails, clear warning signage, and edge protection

Answer

Cones placed along the edge

Answer

Warning tape only

Answer

Verbal warnings to workers at the start of each shift

Question 3

What is the correct sequence for demolishing a multi-storey building using the top-down method?

Accepted Answer

Remove hazardous materials first, then demolish storey by storey from the top downwards, ensuring structural stability at each stage

Answer

Demolish the ground floor first to bring the building down

Answer

Remove alternate floors to weaken the structure

Answer

Use explosives on all floors simultaneously

Question 4

An excavation is being dug near an existing building. What is the primary structural risk to the adjacent building?

Accepted Answer

Undermining the building's foundations, causing settlement or collapse

Answer

Noise damage to the building's windows

Answer

Dust damage to the building's paintwork

Answer

Vibration damage to internal plumbing only

Question 5

How often must excavations be inspected under the CDM Regulations 2015?

Accepted Answer

At the start of each shift, after any event likely to affect stability, and after any accidental fall of material

Answer

Weekly

Answer

Monthly

Answer

Only at the start of the project

Question 6

During excavation work, a worker discovers an uncharted gas main. What is the correct immediate action?

Accepted Answer

Stop work immediately, evacuate the area, prevent ignition sources, and contact the utility emergency service

Answer

Continue digging carefully around it

Answer

Cover it over and continue work elsewhere

Answer

Attempt to cap the pipe