CITB Specialists Excavation and Groundwork Safety 2

Question 1

What does the 'angle of repose' refer to in specialist excavation work?

Accepted Answer

The steepest angle at which soil or loose material can be stacked without sliding

Answer

The angle at which an excavator boom should be positioned

Answer

The correct angle for installing ladder access

Answer

The angle of the trench support bracing

Question 2

A specialist contractor encounters groundwater ingress during deep excavation. What is the most appropriate response?

Accepted Answer

Implement a dewatering system (wellpoint or sump pumping) and assess the effect on surrounding structures and services

Answer

Continue digging as the water will drain away

Answer

Add more support to the trench and continue

Answer

Abandon the excavation and relocate

Question 3

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

Accepted Answer

A secured ladder extending at least 1 metre above the excavation edge, positioned within reasonable reach of all work positions

Answer

Workers can climb the trench support system

Answer

A rope for climbing in and out

Answer

Steps cut into the trench wall

Question 4

Under UK environmental regulations, what must a specialist contractor do if contaminated soil is discovered during excavation?

Accepted Answer

Stop work, isolate the area, test the material, and dispose of it at a licensed facility in accordance with waste regulations

Answer

Mix it with clean soil and reuse it on site

Answer

Remove it from site and dump it in a skip

Answer

Cover it with a membrane and continue working

Question 5

What is the purpose of a 'permit to dig' system used by specialist groundwork contractors?

Accepted Answer

To formally confirm that underground services have been located and marked, safe digging methods agreed, and specific precautions are in place before digging begins

Answer

To obtain planning permission for the excavation

Answer

To allow the use of mechanical excavation equipment

Answer

To confirm the soil type before excavation

Question 6

A specialist excavation crew is working adjacent to a live highway. What additional control measures are required beyond standard excavation safety?

Accepted Answer

Traffic management plan, Chapter 8 compliant signage, vehicle restraint barriers, and a designated traffic management operative

Answer

High-visibility clothing is sufficient

Answer

A banksman to direct traffic

Answer

Cones placed around the excavation