Fracture system characterization by Pressure Probe

Abstract

Pressure Probe (PreP) is in effect a simplified penetrometer: it measures the mechanical resistivity of the soil at shallow depths dropping the probe always from the same height. The resolution of this technique is very good. It is able to detect e.g., fractures due to their decreased mechanical resistance if they are covered, but in a shallow depth with a reasonable sampling distance. An example will be demonstrated where fracture system of a slowly-moving landslide was characterized enabling also its delineation. In spite of that its maximal penetration is only about 0.5 m it may also give information from remarkable depths in case if fractures reach close to the surface indicating the borders of geological structures in larger depth. An example from India will be shown to present such results. All results have been verified by geoelectric measurements. PreP may also indicate any kind of hidden holes indirectly.