Transcript Excavation - Health and Safety for Beginners

Excavation
Hazards & Controls
Hazards
Collapse of sides
Type of soil structure
is an important factor
What might appear to
be a safe soil
structure can change
dramatically with
changes in the
weather
Hazards - Physical
Materials falling onto people working in
the excavation
People & vehicles falling into excavation
People being struck by plant
Undermining nearby structures
Contact with underground services
Access to excavation
Hazards - Chemical
Fumes from vehicles/plant (C02)
Methane/other gases
Contaminated land/previous use?
Hazards - Biological
Leptospirosis
Previous use e.g. hospitals
Drains/sewers
Rubbish and waste
Control Measures
Tied ladder provides
safe access and egress
Guard rails to prevent
falls
Poling boards extend
above edge to act as
toeboards
Exposed services are
supported
Supported by
timbering and props
Collapse of Sides
Batter sides and ends
Support with timber, sheeting or
proprietary support systems
Use 1.2m as a guide for support, but
assess conditions at all times
Even work in shallow trenches can be
dangerous, especially if bending or
kneeling
Materials Falling into
Excavations
Do not store spoil or other materials close
to excavation – they could fall in or cause
sides to collapse
Provide guard rails and toe boards where
necessary
Wear hard hat in excavations
People & Vehicles Falling
into Excavations
Provide guard rails &
toe boards (2m)
Use stop blocks to
prevent vehicles overrunning
Keep vehicles away
from excavations
wherever necessary
People Being Struck by
Plant
Keep workers separate from moving plant
where possible
Plant operators should be trained and
competent
High visibility PPE
Undermining Nearby
Structures
Make sure excavations do not affect
footings of scaffolds or foundations of
nearby structures
Provide temporary support for structure if
necessary
Surveys of foundations and advice of a
structural engineer may be necessary
Avoiding Underground
Services
Look around for obvious signs of underground
services e.g. drains, patching of surface etc.
Use cable locators to trace any services. Mark
the ground accordingly
Use service plan
Dig trial holes by hand
Hand dig if in doubt (particularly for plastic
cables which cannot be detected)
Have emergency procedures/contact in place
Safe Access & Egress
Create steps in excavation
Provide good ladder access or other safe
ways of getting in and out of the
excavation
Fumes
Do not site petrol or diesel engined
equipment such as generators or
compressors in, or near the edge of, an
excavation unless fumes can be ducted
away or area can be ventilated
Protecting the Public
Barrier off all excavations in public places
to prevent falls
NRSWA
Where people may get onto the site out
of hours, backfill or cover excavations to
reduce risks
Supervision
A competent person must supervise the
installation, alteration or removal of
excavation support
People working in excavations should be
given clear instructions on how to work
safely
Inspections
Competent person must inspect:
At start of shift;
After any event likely to have affected strength
or stability of excavation; and
After any accidental fall of rock, earth and other
material.
A written report should be made after most
inspections
Stop work if inspection shows excavation to
be unsafe