ABSTRACT
In slurry shield tunnelling, detailed understanding of the support mechanism of the slurry interacting with the soil at the tunnel face is of great importance. So far, no precise statements can be made about the depositing of bentonite particles in the process of slurry penetration into the soil structure. In order to investigate the phenomena that occur during face support, an experimental set-up based on electrical resistance measurements was developed to study the penetration of slurry into saturated soil. Various tests showed that particle deposition in the grain structure occurred with almost every combination of soil and slurry. The analysis of the electrical resistance over the penetration depth of the slurry clearly showed this by the dependence of the electrical resistance of the soil-slurry mixture. When considering the penetration depth, it becomes apparent that the properties of the fluid that has penetrated the pores of the soil differs substantially from to the initial slurry due to a decreasing particle content of the slurry with increasing penetration distance.
