Assessment of P-Y Approaches for Piles in Normally and Over-Consolidated Soft Clay

The load-bearing behavior of laterally loaded piles in soft clay is commonly determined by using the p-y method as recommended by the American Petroleum Institute (API). The recent application of these p-y curves for monopile foundations of offshore wind turbines necessitates their verification with regard to the large diameter and their response to small loads. Previous investigations from other researchers questioned the validity of the API approach for these conditions and recommend modified or completely new approaches. In this respect, the paper presents a comprehensive numerical study in order to assess a total of six static p-y approaches. It is concluded that none of the regarded approaches is generally valid for arbitrary soil conditions and pile dimensions. The findings from the investigation are finally used for the specification of requirements regarding a new, superior p-y approach.