Trusted elements in the digital model of the tunnel

Abstract

The application of Building Information Modelling (BIM) in Tunnelling involves the generation, co-evolution, and maintenance of digital models. This often requires the collaboration of multiple stakeholders on the same digital model over multiple project phases, which, in turn, necessitates the sharing of responsibility for the same model element among those stakeholders. For example, a niche in the tunnel inner lining may be designed simultaneously by a structural engineer, by a fire safety expert who needs to install a fire hydrant in it, and by a HVAC engineer who needs a ventilation control panel in it. Shared responsibility requires trust. Lack of trust often leads to the duplication of models so that each stakeholder can work on a separate model, free from the influence of the work of others. The consequence is a break-down of model continuity and unsustainable usage of personnel and resources. In this work, we present a method for introducing trusted elements into the digital model of the tunnel. This can be accomplished by anchoring those elements to contractually relevant documents, such as the Employer Information Requirement (EIR) according to the ISO 19650 series. Trusted elements can guarantee formally that a certain contractual or technical requirement has been fulfilled, e.g., that the measurement of carbon monoxide for the emergency ventilation system is designed in accordance with ISO 23431. In addition, formal requirements within a trusted element can be tested automatically by the common data environment (CDE) of the project. In case that one stakeholder changes the trusted element so that a requirement is no longer fulfilled, an automatic alert can be issued. We present a standardized workflow for the creation and maintenance of such trusted elements in a digital model on the use case of the design of a ventilation system in a road tunnel.