SWP123 Version 2.0 ASSA Pty Ltd www.assaohs.com.au Page 1 of
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SAFE WORK PROCEDURES EXCAVATION WORK (over 1.5 metres deep)
SPECIAL INSTRUCTIONS: 1. A Safe Work Method Statement is to be
developed for all high risk construction work, including work in
trenches or excavations greater than 1.5 metres deep. 2. Persons
using powered plant or equipment must hold the appropriate
Certificate of Competency or Licence (if applicable), and be
trained in the safe use of the plant.
Task sequence Identified hazards in task Key processes to be
followed Precautions / PPE required 1. Security of site Traffic
Pedestrians
A worksite must be protected from passing traffic by the use of
appropriate traffic controls, such as road closures (full or part),
detours or side-tracks, barricading and fencing, use of traffic
control devices (such as temporary road signs, traffic cones and
bollards, barriers, portable traffic lights, etc), and traffic
controllers (where a need to manually control traffic flows through
the worksite exists). A safe path for pedestrians must be provided
outside of the work area. A barricade or hoarding of at least 900mm
high must be erected around an excavation unless no members of the
public are likely to be in the area of the excavation. Consider
covering the excavation in addition to barricading. If necessary,
pedestrians may have to be diverted to the other side of a road.
Ensure that a safe means for pedestrians to cross the road is
provided.
Refer to the Manual of Uniform Traffic Control Devices for
advice on the use of signs and devices for work on roads. Traffic
controllers must be trained and accredited. Ensure that pedestrian
pathway is free of obstructions, holes, etc. Pedestrian pathway
must consider the types of pedestrians using the path (including
any special needs, eg, mobility, disability, age, etc.).
2. Inspection of site Cave-in, flooding Stability of structures
Underground structures and services
A competent person is to inspect the site before excavation
commences to assess any risk of cave-in or flooding of the trench
due to ground conditions. Trenches are to be inspected at the
commencement of work each day to ensure that the trench is safe for
a person to enter before any person enters. An excavation or trench
where a person is required to enter should be shored or shielded,
benched or battered to prevent the collapse or cave-in. Control
measures necessary to prevent risk of collapse of adjoining
structures (such as a building or road) are to be identified before
excavation commences and implemented before the risk eventuates.
The existence and location of underground services (such as water,
gas, electricity, Telecommunications, etc) must be carried out
before any excavation of the site commences. Information required
before digging starts should include the types, numbers and depths
of the services. In cases where a risk of damage exists, a
representative of the utility concerned should be requested to be
present on site during the excavation. A written record of all
requests, responses and representations (including the names and
oppositions of persons) should be kept with the job records.
The person conducting the undertaking is to engage a competent
person to ensure the safety of trenching work. Benching height not
to exceed width, and no vertical face to exceed 1.5 metres
Battering angle not to exceed 45o and bottom vertical face not to
exceed 1.5 metres. Dial 1100 before you dig. (Note: this is a free
Australia-wide service for all underground services).
ThisSafeWorkProcedurewasgeneratedon29/11/2013byASSAPtyLtdforuseonlybyCityofDarwin.
SWP123 Version 2.0 ASSA Pty Ltd www.assaohs.com.au Page 2 of
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SAFE WORK PROCEDURES EXCAVATION WORK (over 1.5 metres deep)
Task sequence Identified hazards in task Key processes to be
followed Precautions / PPE required 3. Safety of persons on site
Traffic and mobile plant
Risk of foot injury Falling/flying objects Contaminated
atmosphere Collapse or cave-in
Persons working in areas where traffic or mobile plant is or may
be present are to be provided with and wear suitable
high-visibility garments. Persons working in traffic areas at night
are to be provided with and wear suitable reflectorised garments or
safety vests. Excavations and excavation sites will pose a high
risk of foot injury. Risk of head injury exists where plant or
machinery is used, or persons at work below ground level could be
struck by falling objects or materials.. Provide means to prevent
objects falling into an excavation or trench. Excavations and
trenches adjacent to roadways may be affected by gases from vehicle
exhausts. Excavated material should not be placed less than 600mm
from the edge of an excavation to minimise risk of collapse due to
the weight of the spoil. An excavation where a possibility of
collapse or cave-in exists should be shored, shielded , benched or
battered to prevent the collapse or cave-in.
High-visibility garment must be worn. Persons working on
construction sites must wear head and foot protection, and other
PPE as identified by risk assessment. Safety footwear must be worn.
Head protection must be worn. Provide forced ventilation to
excavation from safe area. Keep spoil, etc, away from top of trench
or excavation. Shoring must be designed to withstand all possible
loadings.
4. Trenching safety Persons falling Trench collapse or cave-in
Safe access and exit
A barricade at least 900mm high must be erected around a trench
that is 1 metre or more deep unless it is not possible or only
workers involved in the trench will be in the area; or another form
of barrier exists (such as excavated materials near the trench).
Excavated material should not be placed less than 600mm from the
edge of a trench to minimise risk of collapse due to the weight of
the spoil. Additional precautions to prevent collapse or cave in
will be necessary where surrounding ground has been disturbed or
surface loads are nearby. Ladders must be provided no more than 9
metres apart in the area where work will be carried out.
Refer to local OHS regulations and codes for trench safety
requirements on construction sites. Do not place loads or materials
in close proximity to trench face. Inspect areas close to walls,
etc, to detect any movement of ground. Ladders must extend 1 metre
above level being accessed.
PRECAUTIONS: The following precautions are to be observed, and
suitable safety signs as shown should be displayed where trenching
and excavation work is carried out.
Additional PPE which may be required when working in trench or
excavation.
ThisSafeWorkProcedurewasgeneratedon29/11/2013byASSAPtyLtdforuseonlybyCityofDarwin.
