An experimental study was conducted to investigate the response of an ice-surrounded structure during earthquake by using an underwater shaking table. In this experiment, the interaction of an ice-surrounded structure with the soft and dense foundation and the dynamic reciprocal motion of the structure caused by an ice floe motion were investigated. It was found that the ice-surrounded structure on a dense foundation had sliding and locking motion occurred during shaking whereas on a soft foundation the displacement of the ice-surrounded structure was larger than the other cases on the dense foundation. Besides this experiment, a numerical analysis was also carried out by using FLIP (Finite element analysis of liquefaction program). The objective of this analysis was to validate the program FLIP for calculation of response of ice-surrounded structures during earthquake motions. This report describes the results of both the experimental and numerical analysis of an ice-surrounded structure subjected to earthquake motions.
In the world, there are some frozen areas in seismic zones, such as the Sea of Okhotsk. In such areas, offshore structures are subject to the seismic load, which simultaneously includes the force induced by an ice floe moving against the structure during earthquake motions. In this sense, it is important to evaluate the response of offshore structures in a frozen sea area during earthquake motions since an appropriate methodology is not available. In this study, an experimental investigation using an under water shaking table and non-linear earthquake response analysis by using the effective-stress-analysis program (FLIP) were carried out. Throughout the comparison between the experimental and numerical results, the applicability of this numerical method to check the safety of ice-surrounded structures is discussed.
