Eppenberg Tunnel: Convertible TBM for Rock and Soft Soil
A bottleneck exists between Gretzenbach and Wöschnau as the sole remaining twin-track section on the Berne–Olten–Zurich rail route. The SBB intends eliminating the Olten–Aarau bottleneck by the end of 2020 with a four-track upgrade. In this way, the availability and capacity will be enhanced and greater flexibility achieved. Towards this end, various part-projects, TP1 to TP11 (Fig. 1) are foreseen. By and large, they embrace structures at Olten junction, a fourth track between Dulliken and Däniken and, at its core, the 3 km long Eppenberg Tunnel as well as extensive measures for linking things up [2].
The Eppenberg Tunnel with its connections to the existing track system is included in Lot A of the overall project. This project consists of the part-projects TP1 to TP3 and TP8, which are executed within the awarded construction contract. TP1 represents the core, the actual Eppenberg Tunnel; the other part-projects constitute operations for integrating/connecting the trenchless tunnel in the overall system (Fig. 2) [1].
1 Project Section TP1
The following article deals at length with part-project TP1. The mined section of the Eppenberg Tunnel is located between km 44.500 (east portal) and km...