21/10/2019

British-Tunnelling-Society's Young Member Evening Lecture on 7th November 2019

BeMo will be hosting the British-Tunnelling-Society's Young Member Evening Lecture on 7th November 2019.

Christoph Huber will be holding a presentation on

New Austrian Tunnelling Method in Hyperbaric Atmosphere
Christoph’s presentation will explore the challenges and innovative solutions associated with the application of New Austrian Tunnelling Method in hyperbaric atmosphere during the con-struction of Tunnel Karl-Friedrich-Strasse in Karlsruhe (Germany). The project – Shortlisted for NCE Tunnelling Festival’s ‘Innovation in Tunnel Excavation’ award – posed a unique challenge with its small overburden (approximately 7m), a poor geol-ogy consisting of gravel, sand and fine sand and layers of rolling gravel. Given the tunnel’s variable geometry (of up-to 180m² tunnel face; 15 m diameter), NATM was chosen as the preferred excavation method. However, due to the inner-city location and a very high water table, the excavation had to be carried out in a hyperbaric atmosphere, of circa 1.0 bar, which created special challenges for the application of wet mix shotcrete. Other challenges included: air losses and the corresponding air flow, and the presence of his-toric buildings along the path of the excavation (including a 125y old brick lined sewer directly above the tunnel alignment).