3D FEM ANALYSIS OF THE CONSTRUCTION PIT FOR A TBM-DRIVEN FLOOD DISCHARGE GALLERY

Abstract

As one speciality of the Swiss hydraulic engineering tradition, several torrent diversion schemes were undertaken dating from the 18^th century, with the aim of using the natural lake as a retention basin. The recent project of flood protection of the lower Sihl valley and the City of Zurich features a gallery of 2.1km length with a 6.6m inner diameter designed for a 330m³/s free flow, discharging into Lake Zurich in an HQ₅₀₀ event. After a short presentation of the main features of the project, the paper concentrates on the target construction pit of the TBM drive close to a major railway line at the built-up lakeside.