Nummerische und physikalische Untersuchung der Ortsbruststabilität bei Grundwasserhaltung
Abstract
The construction of a tunnel in urban areas often takes place in shallow depths close to the ground surface. Nowadays tunnels in granular soils can be excavated as close as half of the tunnel diameter, i.e. only a few meters. A good example is the construction of railway and underground lines in Vienna. In quaternary zones ground water is usually is available, which is linked to a complex and expensive construction. On account of this the ground water table is commonly decreased during construction, remaining a partially saturated zone with negative pore pressure. This capillary effect has a positive influence on the stability of a tunnel face. One thinks of a sand castle of wet sand. This effect is often neglected in practice due to simplicity and additional safety, although it can considerably increase face stability and be therefore cost-effective. For this reason it is important to consider the properties of unsaturated soils in stability calculations. In this project we want to determine and quantify the effect of suction to find an appropriate and economical support pressure (shotcrete or shield tunneling) for the tunnel face. Furthermore the mechanisms causing failure will be investigated. Numerical simulations as well as physical experiments on a small-scale model (in a geotechnical centrifuge) will be performed.
Modellversuch Stabilität Tunnel Zentrifugenmodellversuche
Publikationen
Project staff
Wei Wu
Univ.Prof. Dr.Ing. Wei Wu
wei.wu@boku.ac.at
Tel: +43 1 47654-87311
Project Leader
01.01.2013 - 30.06.2014