ABSTRACT
When tunneling with EPB shields in coarse-grained soils, the flow behavior of the support medium is a decisive criterion for effective face support. On one hand, the support material should possess fluid-like properties ensuring a homogeneous pressure transfer to the face and on the other hand, it needs to exhibit sufficient stiffness for transportation and tipping. Usually, the flow behavior of conditioned soils is assessed using a concrete slump test, whereby a slump range of 10 to 20 cm is recommended by literature. The rheological characterization of soil-foam-mixtures is evaluated analytically. For this, measurements from numerous slump tests are considered. In addition, numerous rheological investigations with Ball rheometers are considered with conditioned sands to get direct measurements of rheological properties. These results can be used for the calibration of a large scale experimental setup. By conducting experiments on different scales, information on the flow behavior of conditioned soil can be transferred from the laboratory scale to the real-world TBM scale.
