If an ice sheet adfreezes to a structure with a circular cross section, such as the pile of a pier or a mooring pile, that is set in the water of a cold region, vertical ice loads acts on the structure if there is fluctuation in the water level due to the tide or other factors. Thus, the possibility of the occurrence 'of vertical ice loads must be considered when designing structure, s that will be subjected to ice loads. The vertical ice load acting on a single pile structure can be estimated by using the theoretical calculation method proposed by the authors. However, at present, there is no theoretical method for calculating vertical ice loads acting on a multi-leg structure. In the present study, field experiments were carried out for the first time on ice loads acting on multi-leg structures in an attempt to establish a theoretical method for calculating ice loads acting on such structures.
The vertical ice load acting on a single pile structure can be estimated by the theoretical calculation method proposed by the authors Terashima et al. (1997, 1998), the accuracy of which was verified by their results of the first field experiments conducted on the uprooting of piles in a full-scale model. However, apart from the theoretical analysis performed by Kerr (1978) and laboratory experiments conducted by Christensen (1986), there have been almost no studies on vertical ice loads acting on the piles of a multileg structure. In the present study, therefore, field experiments were carried out for the first time on vertical ice loads acting on multi-leg structures in an attempt to establish a theoretical method for calculating ice loads acting on such structures.
