Historical overview of CPT-based design methods

The Cone Penetration Test (CPT) is used for many decades in order to evaluate the pile bearing capacity. Pieter Barentsen developed the CPT around 1930 in order to investigate the soil resistance. However, Boonstra was the first, in 1940, to used the cone resistance of the CPT as the unit pile bearing capacity. From this moment, the CPT became very important in the evaluation of the pile bearing capacity. An overview is given about the most common pile design methods, which are based on the in-situ Cone Penetration Test (CPT). This overview will start with the evolution of the CPT, followed by a brief presentation of the methods in use. An important part, in pile design methods, is the averaging procedure of the cone resistance over an influence zone around the pile tip. Since the pile tip is much wider than the tip of the CPT cone, the influence zone of the pile is also much larger, therefore the cone resistance has to be averaged over the influence zone around the pile tip. Unfortunately, the definition of this zone is different for each method in use. Finally, several methods for the pile tip bearing capacity near the interface of a soil layer will be discussed, including related methods from De Beer [1] and White & Bolton [2]