Can Thickness Froude Number be an Influencing Parameter of Ice-Induced Pressure on Vertical Structure?

Abstract

Aspects of expressing ice-induced pressure on vertical structures in dimensionless form as a function of dimensionless influencing parameters are discussed. Based on these, a few previously published experimental data of other researchers on sheet-ice interaction with vertical structures are analyzed, with particular emphasis on the influence of thickness Froude number on dimensionless ice-induced pressure. The data analyzed in this paper, were obtained using fresh-water ice, saline ice, from field and laboratory tests, wherein the ice-thickness-based strain-rate (u/h) varied between 1.0×10-4 sec-1 and 9.0×100 sec-1 while the structure-widthbased strain-rate (u/B) varied from 3.0×10-4 sec-1 to 8.0×100 sec-1. Thus, a wide range of strain rates, from ductile to brittle deformation of ice, has been considered in the analysis. The aspect ratio (B/h) varied from 0.20 to 45 while the contact area varied between 5.0×10-5 m2 to 2.0 m2. The analyses showed that dimensionless ice-induced pressure varies as a decreasing function of increased thickness Froude number, when all other dimensionless independent parameters are held constant. The shape of the indentor was found to have no influence on the dimensionless ice-induced pressure expressed as a function of u/√(gh). The ice-induced pressure data used in this analysis are also presented in dimensional form as a function of pressure-area and as a function of aspect ratio to show the usefulness of expressing parameters in dimensionless form to understand the physics of complex ice-structure interaction problem.