Guidance launched to reduce risk resulting from numerical modelling
Improving skill and care to maximise the benefits of using numerical modelling in geotechnical applications is the aim of a new guidance document published by industry standards body Ciria.
The C791 document - The management of advanced numerical modelling in geotechnical engineering - is aimed at those who commission and manage numerical modelling rather than specialists that undertake the work.
“Numerical modelling is now routinely carried out in geotechnical engineering and if not used properly it can be dangerous,” said Mott MacDonald global practice leader – geotechnics Anthony O’Brien, who co-authored the guide with Geotechnical Consulting Group senior partner Kelvin Higgins.
The authors point to the 2004 collapse of a section of the Nicoll Highway in Singapore during construction as an example of the risks around poor use of numerical modelling. O’Brien adds: “However, if used with skill and care there can be enormous benefits. The new guide aims to outline the information that the project manager and senior engineers need to assemble and, importantly, the processes that need to be put in place for a successful outcome: the 10 steps to better numerical modelling.”
Higgins said: “With increasing reliance placed on the outputs from numerical modelling for design and project planning, it is important for a project manager to have effective procedures in place to manage the use of these methods. The 10 steps is a relatively simple process and can help to demystify numerical modelling. It enables numerical modelling to be well planned and organised and to facilitate an appropriate level of checking and review.”
The guidance creates a framework for people who oversee the process, provide the information needed for this task and use the results of the numerical modelling.
The guidance sets out what numerical modelling is and how to specify a model, as well as how to gather the right information to build, run, calibrate and check a model.
According to Higgins and O’Brien, it is key that any assumptions or idealisations are clearly communicated to the design team as a whole so that it can assess how the results of the model may be used. The new guidance contains a chapter devoted to this process.
“Sometimes numerical modelling is considered to be a black box,” said Higgins. “But this is unsafe and the project management community should consider such an approach to be unprofessional. If the guidance in this publication is followed, then the black box can be eliminated.”