We focus on 3 hazards associated with piling works
1. Operator Competency
2. Ground Conditions
3. Fall Protection for piling Activities
There is no requirement to hold a High Risk licence to operate a piling rig. This is perplexing given that piling rigs are one of the most dangerous pieces of plant used in construction and there have been many fatalities associated with piling rig operations.
Head contractors must be satisfied that operators are competent. This could be done by:
Reviewing an operator’s logbook of hours worked on a particular machine type or
Obtaining a Verification of Competency statement, showing specific checks have been made related to operator competency on different rig types that has been signed off by a “Subject Matter Expert” i.e. an operator who has been in the industry for some time and knows the ins and outs of safe rig operations.
We asked one of our client piling company directors for his thoughts on piling safety. This is what he had to say:
“I honestly think the biggest safety concern in piling and in the industry is inexperience of operators. People need to really consider who they put into their piling rigs. There are too many companies that think a piling rig is just like an excavator. When in fact it is very different. In my opinion, a piling rig can be the most dangerous machine in our industry. This is made even harder with no actual ticket needed to operate one and inexperienced operators.” Sylvan Brooker, LTE Construction Group
Whilst the Industry Standard for Piling work and foundation engineering sites provides excellent information for piling companies, principle contractors and workers, there is a great variation in the industry as to what is considered acceptable fall protection for open piles.
Fall protection is usually provided by installing one or a combination of:
Guard railing, commonly referred to as pile guards, top hats, gates or sheep pens.
Pile hole covers
These controls are used in conjunction with barricades and signage to keep unrelated workers from the area.
While there is no specific standard for pile guards and pile hole covers, these are considered fall protection Engineering Controls and as such, should be approved by an engineer. The following should be considered:
Guard Rails for Pile Holes
Guard rails, as when used for fall protection in general construction, must be engineered to relevant Australian Standards. This also applies to pile guard rails. (Refer: AS1657 Fixed platforms, walkways, stairways and ladders – design, construction and installation or Refer: AS4994 Temporary edge protection – General requirements.)
The distance between guard rails should not exceed 450mm. the distance from the lowest rail to the ground should also be no greater than 450mm. the maximum height of the guard rail should be between 900mm and 1100mm as required for construction handrails throughout the site.
Stability of pile guards should also be factored:
What is supporting the pile guards?
Are they pinned to the ground?
Is the ground suitable to maintain the guards?
Does the joining of gates together to form a sheep-pen provide sufficient impact capacity?
Pile Hole Covers
Pile hole covers, when used as fall protection, need to have the capacity to support a person, should the person stand or fall on the cover. While there is no defined capacity for a pile hole cover, an assessment would require an engineered approved pile hole cover with the ability to meet this capacity.
When selecting pile hole covers, consideration should be given to the material used, commonly this is steel mesh or reinforcing mesh.
The mesh must have a gauge of steel suitable to meet the required capacity
The cover may require reinforced edges to provide stability when spanning a bored hole
The cover must be large enough to span the hole completely with enough overlap on the surrounding ground to ensure stability of the pile hole cover
The cover, if not within guard rails, must be secured to prevent movement. Often pegs or pins are used to secure the cover. Ground conditions must be suitable to hold the pegs or pins firmly in position.
Generally, covers should extend at least 1.5 times the pile hole diameter, but this would depend on a number of factors such as material used, pile hole size, reinforcing and securing methods.
The best means of ensuring that pile hole covers are appropriate is to have an engineer assess and design the covers for the conditions of use. Providing and installing fall protection devices for piles holes must be covered in a SWMS.
What the Safety Regulator Won't Like to See
Victoria document Piling work and foundation engineering sites Industry Standard https://pilingfederation.org.au/wp-content/uploads/2017/08/Piling-Works-Industry-Standard.pdf
Ground Conditions/Working Platform
Piling rigs can weight up to 120 tonnes and can be 44 metres high. It is critical the rig remains stable while operating and during movement. To ensure rig stability a competent person (e.g. a geotechnical engineer) should inspect the working platform after it has been constructed, approve it for use and issue a Working Platform Certificate.