ABSTRACT
In EPB-TBM tunneling, the excavated materials are conditioned for improving the workability of the soil for the purpose of applying pressure to the tunnel face. The workability is defined as the plasticity of the collected soil in the pressure chamber and is an index for the applicability of the EPB machine in different grounds. The effective agents in workability of soil are Consistency Index (Ic), water content, fine grains percentage and Foam Injection Ratio (FIR). The workability of soil can be estimated by the slump test, where the appropriate values for slump vary from 10 cm to 20 cm. In this research, the effect of consistency index on the soil conditioning and related workability are investigated by laboratory slump tests in three different water contents of 10% (IC = 1 to 1.25), 15% (IC = 0.75 to 1) and 20% (IC = 0.5 to 0.75). The main variables of this study are water content and FIR. The results show with increasing IC, the slump values of conditioned material decrease and by selecting a proper value of FIR in a specified IC, it is possible to sufficiently condition the excavated soil.
