Lateral cyclic pile–soil interaction studies on a rigid model monopile

Abstract

The monopile foundation of an offshore wind turbine will unavoidably suffer from long-term cyclic loading during its lifetime, due to impacts from waves and wind. In this paper, a series of tests on a rigid model monopile, subjected to lateral cyclic loading, were carried out in Qiantang River silt to investigate the pile-soil interaction mechanism and accumulated deformation. The tests revealed that the accumulated displacement is closely related to the cyclic load ratio but has no obvious relationship with the relative density of the soil. In contrast, the unloading stiffness is independent of the cyclic ratio but is related to the relative density of the soil. The soil around the rigid monopile under cyclic loading undergoes a shearing stage during the first ten cycles, followed by the densification stage. The shearing stage dominates the cyclic responses of the rigid monopile, within which the total displacement in each cycle reduced obviously; the proportion of the elastic displacement to the total displacement for each cycle increases from ~0.5 to 0.95, and the soil pressures degrade to a large extent. Abstract: The monopile foundation of an offshore wind turbine will unavoidably 23 suffer from long-term cyclic loading during its lifetime, due to impacts from waves 24 and wind. In this paper, a series of tests on a rigid model monopile, subjected to 25 lateral cyclic loading, were carried out in Qiantang River silt to investigate the 26 pile-soil interaction mechanism and accumulated deformation. The tests revealed that 27 the accumulated displacement was closely related to the cyclic load ratio but has no 28 obvious relationship with the relative density of soil. In contrast, the unloading 29 stiffness is independent of the cyclic ratio but the relative density of soil. 30 Disciplines Engineering | Science and Technology StudiesThe soil around the rigid monopile under cyclic loading undergoes a shearing 31 stage during the first 10 cycles, followed by densification. The shearing stage 32 dominates the cyclic responses of the rigid monopile, within which the total 33 displacement in each cycle reduced obviously; the proportion of the elastic 34 displacement to the total displacement for each cycle increases from ~0.5 to 0.95, and 35 the soil pressures degrade to a large extent. 36 37

Distinct-element analysis of an offshore wind turbine monopile under cyclic lateral load

“…Both Figures 7 and 8 present a phenomenon whereby the principle lateral displacement occurs in the first ten cycles, for all cases, and then tends not to vary afterwards. This characteristic was also observed by Chen et al (2015). …”

Experimental Study on Pile‐Soil Interaction Response in Saturated Sand under Long‐Term Horizontal Cyclic Loading

“…e most representative one is Leblanc et al, who conducted model tests of about 10 4 cycles of cyclic loading in dry sand through a self-made long-term horizontal cyclic loading device and proposed a horizontal cyclic cumulative rotation angle prediction model, but this model is in a nonexplicit form [16]. Subsequently, Arshad et al, Chen [17][18][19][20]. Zhu et al realized cyclic loading tests of suction bucket foundation for millions of cycles, and these test results have great significance for predicting the longterm loading response law of offshore buildings [21].…”

A Simplified Nonlinear Method for a Laterally Loaded Pile in Sloping Ground

“…[1][2][3][4][5]. e lateral bearing behavior of these piles is extremely complicated due to sloping ground [6][7][8].…”