Visualization technique for liquefaction process in chamber experiments by using electrical resistivity monitoring

A new technique for real-time visualization of soil liquefaction by using electrical resistivity monitoring is presented. The technique utilizes the relationship between porosity and electric resistivity of soil, which was defined first by Archie in 1942. With the technique, the change of density (including relative density) of saturated soil with respect to depth can be monitored in real-time before, during, and after the dynamic excitation applied. A series of small chamber experiments on single-layer, two-layer, and five-layer soil models were performed and soil liquefaction was monitored in each case. The experiments show that the technique can be used successfully to visualize the change in density of saturated soil throughout the process of pore pressure build-up, liquefaction, and post-liquefaction during shaking experiments. The effects of sand properties, stratification, duration and magnitude of dynamic excitation, and application of successive dynamic excitations on the liquefaction and post-liquefaction behavior of soils are discussed. The technique is particularly promising for large-scale chamber experiments where it can be used to control and monitor relatively large soil mass in addition to determine its state of liquefaction during and after the shaking.