Question

Please write 6 to 10 paragraphs on the risks associated with digging an underground hole.

Write about risks such as workplace safety, cost of digging, delays to works due to hazards or accidents and impacts of the works.

Answer 1

The CDM 2015 Regulations makes the following definition: "excavation" includes any earthwork, trench, well, shaft, tunnel or underground working.

Working in excavations is an extremely dangerous operation which can be made safe by an awareness of the hazards and the precautions to be taken and careful management of the process.

The hazards and risks are usually:

1. Collapse of the sides of the excavation.
2. Materials falling onto the people working in the excavation.
3. People and vehicles falling into the excavation.
4. The undermining of nearby structures causing their collapse into the excavation.
5. Damage to underground services during excavation work causing electrocution, explosion, gas escape, flooding etc.
6. Ingress of water causing flooding

The works should be carefully planned and carried out. Ensure that equipment and materials needed are available on site before work starts. Ensure that the work is directed by a competent supervisor and the works are inspected daily by someone who understands the risks and precautions to be taken. At least once a week the excavation should be thoroughly inspected and also after any event which may affect the temporary support. Such inspections should be documented.

Avoid underground services and make sure not to undermine nearby structures – use safe digging practice and dig away from them. Check the excavation each day before starting work and after any event that may affect its stability. Provide safe access to get in and out. Prevent collapse – shore, bench, or batter back. Do not assume ground will stand unsupported. Prevent people and materials falling in – with barriers strong enough not to collapse if someone falls against them.