A Digital Twin Concept for Civil Infrastructure

In broad terms, a digital twin is a continuously updated virtual representation of some targeted physical reality. The objective of this technical note is to contribute to the current/ongoing efforts of delineating the digital twin concept within the civil engineering domain. An adult digital twin concept is described and exemplified for this purpose–applicable to mature civil infrastructure and with the primary aim of monitoring changes in state over time. The analysis advocates for clearly separating the real and virtual spaces by focusing on objective physical entities as state descriptors, i.e., entities that are not inherently coupled to any specific modeling framework. Also, the analysis emphasizes that model updating consists of two distinct activities, namely parameter updating (Type I) and formulation updating (Type II)—with the latter type requiring research attention.