Monopile lateral loading in dense sand: Comparison between monopile hammered in centrifuge versus PISA design model

An experimental campaign is conducted on 100g centrifuged monopile model, impact driven, into saturated dense sand, down to three embedding depths, corresponding to three slenderness ratios of 5, 4 and 3. These monopiles models are horizontally loaded after the installation without releasing the macrogravity. In this way, the stress state along the monopile shaft generated during the installation phase at 100g is maintained for the horizontal loading. These models are instrumented with optical fibres to measure the bending moment profile along the monopile and get locally the soil reaction profile. The key features of this study are: (i) The monopile behaves from pure rotation to combined rotation-flexure as the slenderness ratio enhanced from 3 to 5, inducing a less pronounced linear rotation-deflection response at ground-level. (ii) The PISA design model captures reasonably well the overall behaviour of laterally loaded centrifuged driven monopiles, even if it is less accurate for the local behaviour.