ABSTRACT
The application range of EPB shields can be extended using conditioning agents. The excavated material serves as support medium during advance in closed mode and must have suitable properties, notably workability and permeability. In this research, the workability of soil-foam mixtures is investigated to elaborate a more precise material description. Up to now, the workability of soil-foam mixtures is typically tested with the Slump Test. However, this test does not provide detailed information on rheological parameters.
Therefore, soil-foam mixtures with varying characteristics were investigated using a Ball Measuring System. The test results provided information on the rheological parameters of the samples, so that the findings could be linked to the results of the slump tests. Since the Slump Test is not suitable for examining coarse-grained gravelly soils or purely cohesive soils, a new penetration test was developed to examine the workability of all mixtures of soils and conditioning agents.
