Integrated workflow with mobile mapping survey and BIM approach to digitalize subway infrastructures

The planning and management of underground public transport is a central challenge for industrialized countries. Since an increasing number of human activities is polarized in metropolitan areas, the effort put into the digitalization for management of the underground lifelines is growing. This paper presents an innovative methodology (SCANtoBIM) to carry out digitization, inspection, and diagnostics of existing underground tunnels to obtain a digital model without disruptions. The multi-dimensional survey system (ARCHITA) allows for collecting data about the tunnel geometry, structural, and functional conditions. Data digitalization and analysis give as-built CAD models and Building Information Models (BIMs). Within the framework of the Management and Identification of the Risk for Existing Tunnels, the proposed process helps the infrastructure manager during the facility service life. The workflow for the digitalization and diagnosis from mobile mapping data has been implemented to obtain a BIM model representing more than 40 km-long metro tunnels.