Abstract：Slurry penetration is the key process of filter-cake formation on excavation face of slurry shield. The characterization methods of soil electrical resistivity can reflect the state of slurry penetration timely and effectively. The electrical resistivity of soil-slurry mixtures were tested by resistivity measurement devices using the two-electrode AC (alternating current) electrical method. The influence of pore water, CMC (sodium carboxymethylcellulose), particle gradation of soil, electrodes distance and slurry concentration on soil electrical resistivity was studied. The results indicate that, the electrical resistivity of soil decreased with increasing of slurry concentration; seawater and CMC both induced the decreasing of soil electrical resistivity, but the action mechanisms of seawater and CMC on bentonite particles are different. The addition of seawater makes the phenomenon of flocculation and aggregation of bentonite particles, and the addition of CMC enhances the ability of ion directed migration in slurry. Contact resistance can also influence on soil electrical resistivity. In order to gaining the reliable soil electrical resistivity, the test should be conducted more than once with different electrode distance.
