CSCS Excavation Safety

Question 1

What is the primary purpose of installing trench boxes during excavation work on a construction site?

Accepted Answer

To prevent the collapse of trench sides and protect operatives working within the excavation

Answer

To store tools and materials underground

Answer

To channel rainwater away from the trench

Answer

To mark the boundaries of the excavation for surveying

Question 2

What must be done before any excavation work begins on a construction site under CDM Regulations 2015?

Accepted Answer

A permit to dig must be obtained, underground services located using CAT and Genny, and a risk assessment completed

Answer

Nothing — excavation can begin as soon as the digger arrives

Answer

Only a verbal agreement from the site manager is needed

Answer

Excavation can proceed once the weather forecast has been checked

Question 3

At what depth must an excavation generally be provided with edge protection barriers under UK health and safety law?

Accepted Answer

Any depth where there is a risk of persons or materials falling in

Answer

5 metres

Answer

3 metres

Answer

Edge protection is only required on roads

Question 4

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

Accepted Answer

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

Answer

Monthly

Answer

Only when the client visits the site

Answer

Weekly inspections are sufficient

Question 5

What is the purpose of 'battering back' the sides of an excavation?

Accepted Answer

To slope the sides to a safe angle to prevent collapse, reducing the risk without using shoring

Answer

To create storage shelves in the trench walls

Answer

To compact the soil for stronger foundations

Answer

To create steps for access and egress

Question 6

What type of access and egress must be provided for excavations deeper than 1.2 metres?

Accepted Answer

A secured ladder or other safe means of access/egress must be provided within the excavation, positioned so no operative has to travel more than 25 metres to reach it

Answer

Operatives can climb the shoring framework

Answer

Ropes are sufficient for access and egress

Answer

No specific access provisions are required if the excavation is less than 2 metres deep