Cyclic p-y Curves of Monopiles in Dense Dry Sand Using Centrifuge Model Tests

Abstract

In this study, centrifuge model tests were used to examine the lateral behavior of amonopile embedded in dry sand through cyclic lateral loading tests. The soil specimens used in thetests were dry Jumunjin sand with a relative density of 80% and a friction angle of 38°. A staticloading test was performed once, and cyclic loading tests were performed four times using fourmagnitudes of cyclic load (30%, 50%, 80%, and 120% of static lateral capacity). The experimentalcyclic p‐y curve was obtained through the tests, and the maximum soil resistance points that werefound for each load were used to find the cyclic p‐y backbone curve for each depth. The twovariables which are needed to define the cyclic p‐y backbone curve, i.e., the initial modulus ofsubgrade reaction (kini) and ultimate soil resistance (pu), were suggested as functions of the soil’sphysical properties and the pile. The cyclic p‐y curve of the first cycle and the 100th cycle wereformulated to present the upper limit and lower limit. The suggested cyclic p‐y curve had anoverestimated soil resistance compared with the existing API (1987) method, but the initial modulusof subgrade reaction was underestimated.