THE EFFECTS OF POROSITY AND SATURATION ON ELECTRICAL RESISTIVITY AND STRENGTH OF SOIL FOR SAND SIZE PARTICLES

Geophysical methods had become increasingly practiced in engineering site characterization as being quicker, more economical, and allow more data to be taken than the present method. Electrical resistivity was conducted by supply generated electric current to the soil and the resulting potential differences are measured. This research presents the effects of porosity and saturation on electrical resistivity and strength of soil for sand size particles. It was a study about the effects of porosity and saturation on electrical resistivity of sand size particles ranges between 0.029mm to 2.00mm. Soil sample was mixed with distilled water and left for 24 hours. The compaction test conducted with different blows in each of moisture content ranged 25% to 40%. Electrical resistivity test as well as pocket penetrometer test had been done right after the compaction test to analyzed and understand the effects of porosity, saturation and cohesion on electrical resistivity. Results show that the effects of porosity on electrical resistivity of sand size particles is when the porosity is high, it means that there is less water in the pore and the resistivity will get higher because water is the good in conductivity. When moisture content is higher, the resistivity will get lower. From test, it shows that there is no specific trend for resistivity against saturation but past studies shows that the lower the saturation, the higher the resistivity. For the cohesion, the lower the moisture content, the higher the resistivity, the higher the cohesion. This showed that the higher the compaction, the stronger the soil will be. The results of this research can be used for geotechnical site investigation by using electrical resistivity.