Can somebody give some light in what the PY curve term is? I suppose it refers to Load-Settlement Curve but I'm not sure. Any reference would be appreciated.
p-y Curves are developed using P = Modulas of Subgrade Reaction x the pile width and y = deflection along the pile length. The method is utilized in some software and oftentimes tends to give a false sense of precision. This problem comes about due to crude estimations of the soil Modulas of Subgrade Reaction, usually derived from vague tables and/or the soil strata are so generalized that a simple chart would give reasonable results. In theory, given good information, the method ought to give a very good picture of the actual pile capacity and the pile deflection. My call is for insisting on good information (soil stratification and modulas for each major strata) to begin with.
PY curves are for the lateral deflection of piles.
For the vertical movement of piles use t-z curves.
See article:
Leland M. Kraft, Jr.; Takaaki Kagawa; Ricard P. Ray
Geotechnical Division of Proceedings of the American Society of Civil Engineers, GT Nov, 1981, pp 1543-1561