Electric Penetrometer for Site Investigations

Several types of penetrometers are being used for the static penetration test which have generally the same basic dimensions but differ greatly in shape and method of operation. A review is presented of the most common mechanical penetrometers, including the Begemann friction cone penetrometer, with their advantages and disadvantages. Subsequently, an electric penetrometer is fully described which contains a strain gage load cell and which permits also the measurement of side friction on a separate sleeve. The resistances are recorded directly and continuously as graphs. The penetrometer has a built-in inclinometer to check the verticality of the sounding. The method provides greater reliability of the measurements than the traditional mechanical cones as various potential sources of error have been eliminated. It allows a great degree of automation and has increased the range of applicability of the penetrometer test.