Response of flexible monopile in marine clay under cyclic lateral load

While monopile foundation is widely used at sandy site in Europe, it is designed and constructed in intertidal zone used only in China so far. Comparing with sandy site, intertidal site typically has different geological and environmental conditions due to upper layer consisting of soft marine clay and daily tide movement, which may lead to considerable difference in long-term behavior of monopile. In order to investigate the cyclic lateral behavior of monopile constructed in intertidal zone, several scaled model tests were conducted. The scaled monopile-soil system contained in-situ soil from intertidal zone was tested with a new designed loading device under static and cyclic lateral load. Behavior of monopile-soil system was obtained and analyzed, which includes assessment of cyclic deformation at pile-head, estimation of static and cyclic p-y curves, dissipation behavior of pore water pressure, evaluation of gapping effect and soil softening zone. Discussion and suggestion for available design are proposed based on the analysis work of test results.