Dynamic ice forces of slender vertical structures due to ice crushing

The dynamic ice forces and structure vibrations generated by crushing failure of ice sheet were investigated by full-scale tests conducted on a cylindrical compliant monopod platform in Bohai Bay, China. The load panels recorded three ice force modes distinguished by ice speed, which cause structure quasi-static, steady-state and random vibrations respectively. Based on the tests data, the physical process of dynamic ice forces in crushing failure was probed, by analysis of mechanical behaviour of ice under compressive loading related to relative loading speed of ice-structure interaction. It is proved that the three ice force modes takes place in loading speeds which make ice fail in ductile, ductile–brittle transition and brittle range respectively. In addition, the key problem from the structure design point of view involved in each ice force mode is discussed.