Abstract:
For monopile, where single pile carries all the lateral forces and moments, predicting top displacement and slope with reasonable accuracy becomes important in design practice. In this study, linear Winkler's (1867) model is created in which monopile is modelled using beam-column element with roller support at its bottom and surrounding soil is represented by linear springs. Matlock's (1970) recommendation has been used to calculate soil spring constant from its Young's modulus estimated through shear modulus. Deflection of simulated pile has been compared for various recommendations of Gmax estimation through SPT values. Predicted deflection showed large variation questioning its accuracy. Since average strain level of the soil during loading is actually unknown, one can assume any strain level to find a desired value of G to match the same deflection for any of those Gmax correlations. Similar analysis showed a large variation in the strain level expected in different correlations. This creates discomfort in taking design decisions and requires finding a way to approximately calculate the applicable average strain level corresponding to the induced deformations at various depths of monopile.