Geotechnical applications and conditions of the observational method

S. van Baars and J.K. Vrijling
Delft University of Technology, Faculty of Civil Engineering and Geosciences, Delft, The Netherlands

Information observed during construction can be used to optimise the remaining parts of the construction of structure. In this article general conditions are indicated for the implementation of the Observational Method in geotechnical engineering. The most important condition is that the uncertain field condition (the observational data) must be clear to measure. For example in case of a brittle soil behaviour, there is no clear indicator to show that the load is approaching the maximum resistance. If a project fulfils all general conditions, a financial risk analysis is necessary to find out whether the Observational Method is profitable. The success of implementation varies strongly per geotechnical discipline. In this article a simplified approach for a risk analysis is given and a number of geotechnical cases are discussed for which the Observational Method can lead to a financial profit. Most of these cases are already informally implemented in daily practice.

Key words: Observational method, geomechanics, design, cost and risk analysis, Bayesian updating