A cubic metre of soil weighs about a tonne and a half. It does not have to be deep to kill someone - it has to fall on them.
Dial Before You Dig Australia and have the plans on site. Struck services - gas, power, water, comms - are the other way trenches kill people.
Spoil goes at least 1 metre back from the edge, and plant stays off the edge entirely. The surcharge from a stockpile or a machine track is what turns a stable face into a collapse.
Inspect before every shift, and again after rain, after vibration, and after any change. Ground that held yesterday is not evidence it will hold today.
Excavation and trenching, shoring, confined space entry and working near services are all in the SWMS libraries - written to your state's Act, regulation and regulator. Browse the libraries →
General information to help you ask the right question - not legal advice, and not a geotechnical assessment. Ground behaviour depends on soil type, water, weather, vibration, surcharge and time. Where the answer matters, get a competent person and, for anything deep or complex, an engineered shoring design. This tool does not do either.
Obras Onsite Pty Ltd · ABN 54 698 828 821
The tools above are free and yours to use. When you need the paperwork behind them reviewed by someone who has run sites, Obras HSE Services is a live consulting business in south-east Queensland.