Document ID: chunk:federal_register_of_legislation:F2016L00416:reg:4:p1
Version: federal_register_of_legislation:F2016L00416
Segment Type: reg
Provision Reference: reg 4 (pt 1/21)
Character Range: 32098–35231

4          CONTROLLING RISKS IN EXCAVATION WORK

The following table lists common hazards associated with excavation work and examples
of control measures:

Potential hazards                    Examples of control measures

Ground collapse                      the use of benching or the installation of ground support (e.g. shoring)
Water inrush                         pumps or other dewatering systems to remove water and prevent build-up
Falls                                ramps, steps or other appropriate access into the excavation
Hazardous manual tasks               rotating tasks between workers
Airborne contaminants                mechanical ventilation to remove airborne contaminants
Buried contaminants (e.g. asbestos)  training to identify buried contaminants and what action to take
Underground services                 obtain information from the relevant authorities on the location
                                     of underground services

4.1              Excavated material and loads near excavations
Mechanical plant, vehicles, storage of materials (including excavated material) or any other heavy loads should not be located in the 'zone of influence' of an excavation unless the ground support system installed has been designed by a competent person, for example a geotechnical engineer, to carry such loads.
The zone of influence will depend on the ground conditions. It is the zone in which there may
be an influence on the excavation including possible ground collapse (see Figure 2).

    Figure 2 Excavated material and loads near excavations

Figure 2 shows an example of:
    * an excavation with shoring that has been designed to carry vehicle and material loads – this may be required where there is limited space around the excavation for vehicle movement and/or material storage, and
    * an excavation with shoring that has been designed only to carry the load of the excavated faces and the related zone of influence.
Any material will add a load to the area where it is placed. It is important that materials are not placed or stacked near the edge of any excavation as this would put persons working in the excavation at risk. For example, the placement of material near the edge of an excavation may cause a collapse of the side of the excavation.
To reduce the risk of ground collapse, excavated or loose material should be stored away from the excavation. Excavated material should be placed outside the zone of influence. Alternatively, a ground support system should be designed and installed to carry the additional loads including any ground water pressures, saturated soil conditions and saturated materials.

If excavating in sloping ground decide which side of the excavation to place the excavated material. Things to consider include:
    * ground conditions
    * access to the excavation
    * existing underground services
    * the need for earthmoving machinery or vehicles to work or move along beside the excavation
    * service installation and backfilling requirements, and
    * any manual work being undertaken in the excavation.
Placing material on the