Dear ITA Members,
We are pleased to invite you to our next episode of the Lunchtime lecture series that will be on Tuesday 13th October at 13:00 CET. This session will focus on ‘Choice of TBM‘ in collaboration with ITA AITES Working group 14.
· TBM type selection – Introduction on different types of TBMs – Brian Fulcher
There are several types of TBMs each aligned to the anticipated ground and water conditions and the Contractor's preferred tunnelling approach including ground support and ground treatment (if any). Generally speaking, there are hard rock and soft ground TBMs each associated with specialized equipment and supporting systems. TBM technologies and equipment are continuously evolving and frequently allow for safer and more productive tunnel construction in increasingly more challenging ground and water conditions. This introduction provides a brief discussion of hard rock, mixed face, soft ground and specialized TBMs frequently used in major tunnelling projects worldwide and will segue to machine selection and use as well as several Case Studies presented as part of this session.
· Multi-criteria analysis for TBM selection – Martino Scialpi
TBM technology has evolved to a point where virtually any ground condition or combination of different ground conditions along the same alignment can now be successfully excavated and supported. While in some case the most suitable type of TBM is still relatively obvious, the increasing number of projects characterized by wide ranges of below and above ground challenges requires some more effort to determine which machine configuration would check all the boxes. This section of the webinar will illustrate the multi-criteria analysis as the tool that allows qualitative/quantitative comparison of alternative TBM methodologies and TBM selection for complex projects. This risk-analysis driven approach is based on in depth review of the geological conditions for proper characterization of related geohazards, as well as identification of other project specific factors affecting the TBM selection rationale.
· TBM selection in practice: Case studies from ACCIONA projects – Pablo Canovas
TBM selection is rarely driven by ground conditions alone. This presentation explores two practical case studies illustrating how geological, hydrogeological, operational and project-specific constraints influence the selection and configuration of mechanised tunnelling solutions. The two case studies address different TBM selection challenges: one reassesses the suitability of a TBM concept in light of actual construction experience, while the other examines the adaptation of a pre-existing machine configuration to demanding ground conditions. Particular attention is given to the trade-offs between excavation performance, groundwater and ground management, operational flexibility, machine complexity and risk, highlighting the importance of considering the complete tunnelling system when selecting the most appropriate solution.
Registration: https://www.itacet.org/