Judgement in geotechnical engineering practice

Professional judgement is the basis for many of the decisions taken by geotechnical engineers to make progress in the design, execution and works supervision. Judgment is a mandatory component of any engineering achievement, essential to assess the various uncertainties that inevitably affect engineering practice. Confidence in such judgements can result in small to big consequences, not only for the engineer itself, but also for others, sometimes with the risk of human loss and significant damage. The definition and the development of judgment in geotechnical engineering is discussed. The bases of the judgement are analysed in detail and the heuristics and bias, responsible for failures in the judgment, are identified. The importance of experts' judgement and codification are highlighted and ways to improve judgment are also described. The lessons learned in a case study of one accident and two incidents that have occurred during the execution of the Lisbon Terreiro do Paco metro station construction works are presented to highlight the importance of an informed decision making informed through the engineering judgement.