Experimentelle Untersuchungen zum Verhalten von zyklisch horizontal belasteten Monopiles

Experimental investigations of cyclic laterally loaded monopiles.

The prediction of accumulated deformations due to cyclic loading with monopile foundations of offshore wind power plants is a real challenge. Adequate predictions require profound knowledge about soil-monopile interaction behaviour due to cyclic lateral loading. A number of monopile tests are performed in the geotechnical testing pit at TU Berlin in order to investigate that interaction behaviour in more detail. Short, intermediate and long open ended steel pipe piles have been jacked into water saturated sand after instrumentation and subsequently subjected to cyclic lateral loading with varying load amplitude and simultaneously acting static vertical load. Final vertical jacking pressure and sand plugging inside the pile were measured during pile installation. Pile head displacements, pile deformations, horizontal soil displacements close to the pile shaft, pore pressures as well as settlement of the soil surface were measured during the pile load tests. The paper presents concept, preparation and execution of the pile tests and illustrates main results as well as findings from these tests.