All PCBUs must manage the risk of a fall by a person from one level to another.  This include excavations.

As a general rule, a 1m x 1m rule should be applied for barricading, meaning for each meter in depth, the barrier should be set back 1m from the edge of the excavation.

These barricades must be further back if they’re acting as edge protection.

Signs must be placed at locations around the perimeter of the excavation where they can be easily seen.

The John Holland Barricading and Signage Matrix identifies the barricading requirements for excavations and trenches.

• Most effective control – solid barricading (e.g. water filled barriers or jersey barriers)
• Alternative controls – hard or soft barricading (e.g. scaffold tubing 2m back)
• Other controls – Danger signs and information tags

With so much planning going into the type of excavation and ground support required, the risk of falls from heights is often overlooked or not managed adequately.

Controlling the risk of falls from heights can be managed in a number of ways, including:

• Using trench box extensions or trench shields with sides extending 900mm above the ground
• Installing covers on trench boxes
• Inserting guard rails and toe boards immediately next to the supported excavation
• Installing landing platforms or access structures such as scaffold towers inside deep excavations
• Erecting barricades at least 2m back from the excavation
• Backfilling the excavation as work progresses

Excavation Safety Guide. Worksafe New Zealand

Some shoring boxes are designed with edge protection and safe access built into the design to control the risk of falling at heights when working near excavations.

Trench shields with guard rails attached and safe access provided by tied off ladder.

Victorian Compliance Code – Excavation 2019