Evaluation of volumetric rock fragments content in soil based on electrical resistivity tomography

In order to evaluate the performance of electrical resistivity tomography applied for estimating rock fragments content，the application of estimation approach to volumetric rock fragments content in stony soils was investigated by numerical simulation. The stony soils were assumed to be biphasic medium with rock fragments embedded in fine earth. Electrical resistivity tomography measurements were simulated by using finite difference analyses on numerical models. The rock fragments inside models were non-jointed and random distributed, effect of rock fragments size and soil water condition were taken into consideration. The results show that the effective electrical resistivity is a function of rock fragments content if the resistivity of the two phases is known, this is in agreement with theoretical prediction. The result approves the applicability of electrical resistivity tomography for volumetric rock fragments content estimation. The approach is better applicable for the condition of wet soils, and can be an important tool for soil basic research and provide references for soil classification and quality evaluation.