APPLICATION OF RESISTIVITY CPTU IN EVALUATION OF CONTAMINATION SITE FOR PESTICIDE FACTORY

Resistivity piezocone tests (RCPTU) is not only include the conventional piezocone tests, the continuous profile of electrical resistivity can also be obtained through this test. Therefore, the RCPTU has a wide application prospect in the environmental geotechnics. Electrical resistivity is a fundamental parameter to characterize the conductivity of soil, it is one of the inherent physical properties of soil. Each type of soil has an inherent resistivity, and its variation probably means that the soil is contaminated. Based on resistivity piezocone test results on a contaminated pesticide factory site, the influences of different pollutants on resistivity are analyzed in this paper. The identification of pollutants distribution and the contamination degree based on the resistivity index is also preliminary studied. Considering that the soil bulk resistivity can also be influenced by void ratio or relative density, and it is advised measured resistivity should be equivalent to a specified relative density which can be measured by RCPTU. Comparative analysis between the equivalent and inherent resistivity is conducted, and the deviation and rate of deviation are used to determine the pollutants distribution and degree of pollution. The results show that the change of resistivity can reflect the presence and degree of pollutions well.