As-built documentation of segmental lining rings in the BIM representation of tunnels

Abstract

While pending full standardisation, the application of BIM in tunnel projects still requires customised solutions for many aspects of the design and construction phases. During construction of the tunnel, the position and orientation of segmented lining rings follows the actual path of the TBM, which is prone to steering tolerances. Hence, the final location of the lining segments is not fully determined in the design stage. The contribution presents methods and examples of the as-built documentation of segmental lining rings. Positioning data from the TBM data acquisition is employed to determine the orientation and location of each installed ring. Pre-defined geometrical prototypes (families) in the BIM system are then activated, semantically assigned to the respective ring number in the tunnel and put into their actual position by means of geometrical transformation operations. For each installed segment, project information is then linked. The data include the loading history from thrust cylinders, the operation and grouting pressures as well as the segment’s life cycle documentation. This information is highly valuable in the documentation, assessment and analysis of segment damages as well as in considerations of durability and maintenance requirements in the commissioning and operation stages of the project. Key aspects of the proposed method are the connection between BIM and TBM data acquisition, the determination of geometrical transformations and the link of semantical information. Application examples demonstrate the applicability of the proposed approach.