What’s the risk?

2 November 2017

This month I am stealing a comment hook from the British Tunnelling Society again. At the October meeting, the evening’s lecture was on the management of risk in tunnelling and major infrastructure projects.

The recording will be available from the Institution of Civil Engineers website, and I bring it up because in this issue of Tunnels and Tunnelling International we have put together a special focus on geotechnical risk in tunnelling. Readers interested in the topic might like to visit the website for bonus content (www.ice.org.uk).

The section in the magazine begins on and contains fi ve articles. The fi rst is an interview with a geotechnical expert regarding the role of the ground model and the potential for change in how construction plans for ground conditions. It also goes into what the specialists like to see in a project.

The second is an article looking at the relationship between site investigation spending and level of risk, as far as it is possible to work out such a relationship. It touches on the transition to a risk-sensitive approach to such investigation, rather than just a budget planning exercise.

The third is an article that looks at some of the software packages available in the fi eld, and some of the aims of the developers, which include helping designers to achieve a better understanding of lining behaviour, interaction with the ground, and a collective, collegial approach to data use.

The fourth comes from the British Geological Survey’s (BGS) Hazard & Resilience Modelling Team, which has developed a new shrink-swell 3D dataset, called ‘BGS GeoSure Shrink–Swell 3D’ that delivers an insight into the properties of the subsurface. The shrink–swell 3D data is a regional hazard susceptibility map that identifi es areas of potential shrink–swell hazard, in three dimensional space, at intervals down to 20m in the London and Thames Valley area.

Finally, we have a case study from Canada, as Toronto is preparing to build 22km of tunnels to improve waterways in the Great Lakes Basin. Mark Bruder of R.V. Anderson Associates Limited, Daniel Cressman of Black & Veatch, and Robert Mayberry with the City of Toronto outline the geotechnical investigation program for the Don River and Central Waterfront Wet Weather Flow System.

Risk management is an important and evolving fi eld in the industry and possibly one that we have not covered enough in recent years. High profi le events and legal cases always bring it to the front of everyone’s minds, but it has benefi ts for the technical solution provided for a project, as well as protecting companies and individuals when a project or activity does not go entirely to plan.