Document ID: chunk:federal_register_of_legislation:F2016L00416:reg:4:p14
Version: federal_register_of_legislation:F2016L00416
Segment Type: reg
Provision Reference: reg 4 (pt 14/21)
Character Range: 66980–69762

to be carried out without positive ground support (that is, shoring), the continuing safety of the excavation will depend on the conditions arising during construction.
If the conditions during construction are not as expected, or if conditions change during the course of the work (for example different soils, heavy rain/flooding) action should be taken immediately
to protect workers, other persons and property. Implement appropriate control measures such as temporarily suspending work until the ground is stable or, if necessary, providing positive ground support.

Benching is the creation of a series of steps in the vertical wall of an excavation to reduce the wall height and ensure stability (see Figure 9). Benching is a method of preventing collapse by excavating the sides of an excavation to form one or more horizontal levels or steps with vertical surfaces between levels.

Figure 9 Benching

Battering is where the wall of an excavation is sloped back to a predetermined angle to ensure stability (see Figure 10). Battering prevents ground collapse by cutting the excavated face back
to a safe slope. Battering should commence from the bottom of the excavation and in some circumstances it may be appropriate to use a combination of the two methods on an excavation (see Figure 11).
Figure 10 Battering

Figure 11 Combination of benching and battering controls

Benching and battering of excavation walls can minimise the risk of soil or rock slipping onto
the excavation. Control measures should be designed by a competent person (for example geotechnical engineer) and be relative to the soil type, the moisture content of the soil, the planned height of the excavated face and any surcharge loads acting on the excavated face.
It is not necessary to bench or batter the face of excavations which a competent person determines are in stable rock or has assessed that there is no risk of collapse. When benching
or battering the walls of an excavation, an angle of repose of 45 degrees should not be exceeded unless designed by a competent person and certified in writing.
Benches should be wide enough to stabilise the slopes and to prevent material from the top falling down to the working area. They should also be sloped to reduce the possibility of water scouring.
The size and type of any earthmoving machinery to be used and any related haul routes should be considered when designing the face slopes and widths of benches.

    6.2              Shoring

Shoring is a positive ground support system that can be used when the location or depth of an excavation makes battering and/or benching impracticable. It should always be designed for the specific workplace conditions by a competent person (for example an engineer).

Shoring is the provision of