CORRELATION OF ELECTRICAL RESISTIVITY WITH UNCONFINED COMPRESSIVE STRENGTH , Cu FOR SANDY SIZE PARTICLES

Stability and the integrity of the ground area of many constructed and natural structures have been the key studies of geotechnical engineering. Implementing soil investigation in order to precisely determine the engineering properties of the soil that made up the ground area is crucial for a proper design and successful construction of any structures. Geotechnical investigation, in typical conventionally means would involve borehole sampling and many tedious methods which are costly, time-consuming and invasive to ground area. Alternatively, geophysical method of surveying subsurface rocks in ground area provide more rapid, cost effective, convenient and non-invasive as substitute mechanism. Geoelectrical survey provides attractive mechanism as its shows promising relation with many geotechnical parameters of the soils. In addition to that, we also benefited from its feature which can evaluate spatial and temporal variation of moisture and heterogeneity of subsoil. However, in order to employ such means for geotechnical investigation, study must be done to see the correlation of soil parameter with the soil electrical resistivity, which is the fundamental concept of geoelectrical survey. We can later predict the soils proportion and behaviour based on electrical resistivity parameter. Despite many study done on many geotechnical parameter of the soil with its correspond resistivity value, there are lack of study that determine the correlation soil strength parameter with it resistivity value. This research particularly aimed to establish the correlation of electrical resistivity with unconfined compression strength, cu. Another essential aim of the research is to study the relationship of other soil geotechnical parameter, such as moisture content, porosity and saturation of sandy size particles with the resistivity value. Soil samples were prepared at certain moisture content and applied with different number of compaction blows. We then tested the soil’s electrical resistivity tests and its unconfined compressive strength.. All the pertinent data were collected and analysed. The results of the tests illustrate crude but distinct relationship between electrical resistivity and unconfined compressive strength, cu of the soils. The increment of soil resistivity shows the similar pattern to the soil unconfined compressive strength. We later observed similar interaction of the selected parameters (moisture content, number of compaction blows, saturation) with the soils resistivity value. Overall results showed as the resistivity in soil increases, the moisture content decrease. The increment in resistivity also shows the increment in saturation rate and compaction blows number.