Author(s): F. T. Christensen; P. Tryde
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Keywords: No Keywords
Abstract: Uplifting ice forces are induced in frozen-in structures when the water level changes. The classic (plane) case of a long vertical wall was first solved by Lofquist (1944,1951). A formula predicting the maximum force per unit length was derived on the basis of the theory of elasticity. In the present paper, a new formula predicting even larger forces is presented. Relatively little attention has been paid to this problem because most vertical walls subjected to vertical ice forces are part of a strong and often monolithic structure of large gravity. Such structures generally suffer less damage than lightweight structures, e. g. pilings. Lofquist assumed a crack-free ice sheet and found the maximum force by limiting the bending stress close to the wall to the flexural strength of the ice. An even larger force may be induced in the wall after formation of a crack in the ice near the wall and parallel to it. By assuming the bending moment at the wall to be zero, and by assuming that the crack at the wall can transmit shear forces, a new ultimate uplifting ice force in the wall is found. This force is 55% larger than the hitherto assumed ultimate force.
Year: 1986