Structure and Process Design. Why are we getting it wrong?

Construction incident causes death of two workers

What can we learn about structure design and the safe design process?

In October 2016, two workers employed in a $25 million development at Eagle Farm Racetrack in Brisbane, were killed when an 11 tonne concrete panel fell over and crushed them.

The large concrete drainage structure, consisting of four individual concrete panels (the walls), were progressively being lifted into place with a crane when two panels fell forward, one after the other.

The men narrowly avoided the first panel falling, however they were subsequently crushed by the second panel, causing their deaths.

Structure Design and the Safe Design process. Why are we getting it wrong?

When we see incidents like this one in Queensland which resulted in the two workers being crushed to death, it makes you wonder. How, in this day and age, does this happen?

We can not help thinking about all the possible design solutions that could have been adopted to prevent the two workers being exposed to the precast panels collapsing. It raises the question – did the designer have time to think about this, to consult, to plan and to talk to people with experience? What control measures could have been put in place to mitigate the construction risks?

WorkCover Qld* proposes the following control measures

WorkCover Qld proposed the following in their Safety Alert – Concrete Wall Panels:

“Control measures to prevent such collapse are to be applied before workers enter the pit.

Concrete wall panels should not be erected unless the following has been carried out:    

• Each wall panel is provided with a minimum of two braces that are attached to the face [1] of the panel and anchored to the ground with engineer designed footings.
• Each panel is provided with an effective way to restrain the bottom of the panel when it is installed.
• The panel restraint system, including brace footing details, is to be designed and certified by a suitably qualified professional engineer (in Queensland the engineer is required to be a Registered Professional Engineer of Queensland). The engineering certification must be on site.
• Workers involved hold the appropriate high risk work licence:
  • tilt-up panels – Intermediate rigger
  • pre-cast panels – Basic rigger minimum
• A comprehensive safe work procedure (i.e. safe work method statement) is to be developed by the panel erector and verified by the principal contractor. Responsibilities of every worker (including the rigger) should be specified in the procedure. 
• The procedure should include detailed diagrams that include the relative position of the mobile crane to the panels, the sequence of panel installation, and details on the panel restraint system. 
• Prior to work commencing a pre-start meeting should take place to ensure all workers are familiar with the procedure.”

Safety in Design

This very sad, but serious incident is what Safety in Design (SiD) is all about. Eliminating hazards through good design. We all need to learn from these tragic events.

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This is an updated article from a previous Safety Alert notice from October 2016.

*Source: Injury Prevention Safety – Alerts at worksafe.qld.gov.au, first published 12 October 2016, updated 17 July 2018.