NEBOSH CC Excavation & Ground Work Hazards

Question 1

What is the primary hazard that must be controlled when carrying out excavation work on a construction site?

Accepted Answer

Collapse of the excavation sides

Answer

Excessive noise from plant

Answer

Dust generation

Answer

Surface water drainage

Question 2

Before commencing any excavation work, which essential check must be carried out?

Accepted Answer

Survey for underground services

Answer

Assess the colour of the soil

Answer

Check the weather forecast

Answer

Measure the noise levels

Question 3

What is the recommended distance from the edge of an excavation that heavy plant and spoil should be kept?

Accepted Answer

At least 1 metre from the edge

Answer

At least 0.5 metres from the edge

Answer

At least 2 metres from the edge

Answer

At least 3 metres from the edge

Question 4

Which type of support system uses horizontal boards (poling boards) held in place by adjustable struts?

Accepted Answer

Timbering (traditional shoring)

Answer

Sheet piling

Answer

Hydraulic shoring

Answer

Trench boxes

Question 5

What must be provided at all excavations to allow workers to exit safely in the event of a collapse or emergency?

Accepted Answer

Safe means of access and egress such as a ladder

Answer

A warning siren

Answer

An emergency first aid kit within the excavation

Answer

A CCTV system

Question 6

At what depth does an excavation typically require a formal support system to prevent collapse?

Accepted Answer

When the sides cannot be safely battered back, typically from 1.2 metres

Answer

Always at depths exceeding 3 metres

Answer

Only at depths exceeding 5 metres

Answer

At any depth in sandy soil