Safety in Design in Geotechnical Engineering
Scott Lines, Senior Geotechnical Engineer, Red Earth Engineering
The resources industry is considered an inherently hazardous industry, it’s a complex system where people often work under high pressure for long hours, often in a remote environment. There are significant risks to the health and well-being of the workers involved. To mitigate these risks safety must be prioritised in every phase of operations, including from the conceptual to the detailed design phase.
The critical role of safety in design
Safety in design plays a critical role. It is an important process that refers to the incorporation of safety considerations and measures right from the conceptual phase of a project and is carried throughout. The approach aims to identify and eliminate or mitigate potential hazards before they become real-life threats. Most jurisdictions have legislated safety in design, requiring some form of a systematic approach to the design of structures, plants, and materials. Throughout this article, we will touch on key steps for successfully incorporating safety in design, common pitfalls, and why this is important to geotechnical professionals.
Closing the gap between work imagined and work completed
A core recommendation for ensuring safety in design is ensuring that all key stakeholders have a seat at the table. This includes people with the relevant knowledge and experience being engaged early and regularly. Safety in design is more than a workshop and once-off report/worksheet. It is an ongoing commitment throughout the project lifecycle to maximise the safety outcomes. To achieve this goal, it is important this includes those closest to the actual work, the people performing the tasks. Within the resources industry, there is often a gap between the work imagined and work completed, having those who complete the task involved in safety in design minimises this impact. Furthermore, all too often a key safety recommendation in the design phase is to shuffle the responsibility of managing the hazard downstream with an outcome vaguely stating something along the lines of “Risk Assessment to be completed prior to starting the task.” Instead of critically engaging with the hazards to mitigate or eliminate them. An example is the 2020 Grosvenor incident; the Risk Assessment for spontaneous combustion was scheduled to be complete as a separate activity from the goaf drainage Risk Assessment (for those unfamiliar, goaf is a term used to describe the part of the mine from which the coal has already been removed and is subsequently allowed to collapse). The spontaneous combustion Risk Assessment was delayed until two and a half months after production started, the serious incident occurred during this time. The Board of Inquiry would later conclude “that a spontaneous combustion-initiated methane explosion was the probable cause of the first pressure wave”.
This follows into the next issue surrounding safety in design. A significant number of controls put in place are still administrative. A recent review into fatal accidents in the Queensland mines and quarries determined that 62% of the controls put in place after a serious accident (one that could result in hospitalisation or death) were administrative controls only (Brady Review, 2019). Administrative controls are some of the weakest controls possible. Although this review focused on why mine workers died over the course of 2000 to 2019 in Queensland, there is no reason to assume that controls used in safety in design are more effective than those imposed following a serious accident. Research by Russell McMullan (2019) into safety in design in the New Zealand transportation industry concluded that safety in design had limited influence on safety outcomes. Despite some excellent guidelines and procedures being available, safety in design is still often considered late in the project for major design changes to take place.
Consider uncertainly at all costs
When considering geotechnical hazards and risks there can be a large amount of uncertainty, geotechnical investigations often comprise less than 1% of the total project costs (with research by Littlejohn in the 1990s pointing to a figure nearer to 0.1%). A more recent example closer to home is Snowy Hydro 2.0 having $100 million set aside for geotechnical investigation on a project that is currently projected to cost $12 billion, a tunnelling project at that! Based on this information, having a large amount of uncertainty of geotechnical hazards and risks should not be surprising. Such uncertainty must place more emphasis on ensuring safety in design features prominently within the project at all stages. Particularly early during the project at the conceptual stage, when the costs of enacting potential changes are considerably less; see Figure 1 for a conceptual representation. Throughout any project, the team should be asking themselves repeatedly, “Can we make it safer?”
Figure 1: Cost of changes and opportunity to influence safety throughout a project (Russell, 2019).
Another aspect of the geotechnical industry, or the resources industry overall, is the nature of continuous change. Resources follow a boom-to-bust cycle; projects are constantly being moved around, brought forward, pushed out, or there is personnel change or scope creep. This compounds the uncertainty and requires robust change management procedures. Each time a design is changed, the change management system should trigger a review of how the change impacts safety. For example, within the tailings space, the introduction of the Global Industry Standard on Tailings Management (GISTM) has highlighted the need to ensure design intent verification (Requirement 6.2) is being met and the implementation of a formal change management system, with the addition of periodic delivery of a Deviance Accountability Report (DAR) from the Engineer of Record (Requirement 6.5). Similarly, most companies have their own change management system in place. Ensuring consistency and proper application is the hard part.
Conclusion
Overall, safety in design is a critical process that needs to be incorporated early and continuously. Implementation of safety in design should not be restricted based on budget or schedule constraints, thrown into a spreadsheet at the conclusion of a detailed design report, but should instead feature prominently throughout the project.