Author(s): Mauri Maattanen; Juhani Hoikkanen
Linked Author(s): Mauri Määttänen
Keywords: No Keywords
Abstract: The Kemi-I lighthouse in the Gulf of Bothnia was furnished with a conical test structure and instrumented to measure ice loads starting in winter 1984/85. From the very beginning it was seen that the failure mode of level ice differed from that observed in scale model tests: a stable pile-up of ice was forming in front of the structure. In addition, the total measured ice force did not correspond to the forces obtained from model tests or analytical calculations. In subsequent research efforts, model ice properties were improved ti observe more closely the effects of snow friction on top of the ice sheet, and to give more realistic ice cracking patterns and failure modes. A new theoretical model to study ice pile-up effects to ice forces on a conical structure was developed. Existing methods were also modified and their validity studied. The new ice force calculation procedure based on an elastic wedge resting on elastic foundation. Bending moments caused by the edge load and distributed pile-up loads in the wedges are calculated using FEM. The total force integration logic is based on ice edge crushing and the ice wedge bearing capacity. The new ice force calculation procedure is compared with results of full-scale measurements and scale model tests. Comparisons between the new procedure and former calculation methods are presented. Also the effects of geometry and ice properties on ice load are shown. The correspondence between the calculations and measurements appears to be good.
Year: 1990