ABSTRACT
The GPE line 16 projects offer the EGIS-TRACTEBEL group a unique opportunity to analyse tunnelling methods for 9 TBMs (11 TBMs in total as 2 were reused) and their impact on progress rates, in a similar context in the Paris region. In this article, a comparison of the different methods is presented, focusing on the possible impact of the designer’s choices. First of all, the dimensions of the shaft, the specifications of the machine, the working hours, etc. are considered in order to analyse the progress rates from the launch to reaching 200 m of tunnel excavation. A comparison is also made with running-in after passing through a shaft.
Given the impossibility of considering all the technical complexity and parameters to be taken into account, certain aspects, although fundamental to the design choices, have not been considered, in particular those related to the general planning of the project, and the financial and environmental costs of the complex. Especially, certain assumptions about the excavation distance considered and other simplifications have been adopted in order to complete this study.
The analysis carried out does not draw any definitive conclusions but is offered as a starting point for considerations to be acknowledged for future projects by sharing the lessons learned from the L16 project.
