Mark Creighton, CGL Director took part in an exclusive round table discussion on the observational method at the GE Basements Conference in October.

Since the launch of the new Ciria C760 guidance on embedded retaining wall design, the industry has been encouraged to use the observational method. Senior consultants and contractors discussed how the industry could benefit from the observational method, and identified some of the barriers against using the technique.

Collaboration is key to success and Mark commented the industry was not sharing as much data as it should or probably could. As an example he explained how sharing data on schemes across London could benefit all.

“We think we understand London ground conditions, but there are things we are continuing to learn as we develop deeper. People are reluctant to share geotechnical information and it’s a terrible shame.”

Other managers commented that trigger levels are being set too low in order to address the risks of movement in a project. It was agreed around the table that a lack of long term baseline monitoring ahead of construction made it difficult to improve specification and design briefs.

Mark added “For infrastructure projects we can afford to invest in that monitoring, but in a commercial building project…there just isn’t the time to have six weeks of baseline monitoring before the programme kicks in. It comes down to clients being willing to invest in monitoring from the onset rather than just seeing it as a protective measure.”

They also discussed various other hurdles and forces including: winning client confidence, improving the brief, perception of the industry, quality of data and the future of observational method.

Ground Engineering Magazine has just released a full article on the discussions at