ABSTRACT
Tunnel lining designs are complex, requiring the combination of both geotechnical and specialist structural skills, often demanding thousands of hours of design effort for a single detailed design. The design is computationally demanding, and much of the design process needs to be performed consistently across different projects. As such, the initial development costs of an automation tool for tunnel lining design is justified to realise long-term benefits of improved design quality and time savings.
TunLIN is one such automation software that has been developed by the author and in-house team at Jacobs. At the core of TunLIN, the essential tasks which are required for all (or almost all) tunnel lining designs are performed from the fewest number of user inputs, and importantly, inputs are only ever defined once and in a format that is easily auditable. The calculations that TunLIN performs are processed in coded modules, using multiple programming languages. The source coding is fully auditable, protected and secure, with past revisions backed up. The user interaction with TunLIN is managed through AutoDesk Dynamo, specifically through the Civil 3D platform. Here, the project topographical and geospacial information can be pulled into TunLIN directly from the Civil3D alignment, or, alternatively, this information can be input by the user through tables within an Excel user input file. This single source of truth also contains material and action factors, load combinations, soil model, joint model amongst others. TunLIN can perform tunnel design using closed-form methods, or it can autonomously generate Finite Element models in SAP2000 or Plaxis; including extracting results and performing post processing.
This paper presents an overview of how TunLIN could be used to design a section of in-situ concrete tunnel lining for a new build nuclear power project using SAP2000, in particular how TunLIN could be a benefit on such a project where designs must undergo the greatest rigour and due-process.
