Free fall penetrometer tests in sand: Determining the equivalent static resistance

Abstract

Free Fall Penetrometer (FFP) tests provide an efficient way to determine the penetration resistance at shallow depths in sandy soils, and are being used increasingly in geotechnical, geomorphological and coastal engineering applications. A limitation of free fall penetrometers is the effect of their high velocity on the penetration resistance. This affects the drainage condition, creates a viscous-type enhancement of the mobilised strength, and also introduces inertial drag forces. It is useful if the measured FFP resistance can be adjusted back to the resistance that would be expected in a standard Cone Penetrometer Test (CPT) at the same location. With this adjustment, the resistance can b..