SBB Zimmerberg base tunnel

Project overview

The Zimmerberg base tunnel between Zurich main station and Thalwil passes through an urban area with minimal cover at certain points, making the driving operations for the double-track rail tunnel correspondingly challenging. Driving operations through the rock incorporated both the use of a TBM and conventional blasting. In granular soil, the tunnel was excavated using a hydro-shield TBM, and auxiliary construction measures (soil injections, pipe arch) were taken to reduce the risk of excessive settlement.

Expertise involved




Our services

Overall management and project management from project planning through to execution (including senior site management) for the Brunau‒Zurich and Brunau‒Thalwil sections.

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