A Probabilistic High-Pressure Zone Model for Local and Global Loads During Ice-Structure Interactions

Abstract

For temperate ice regions, guidance provided by current design codes regarding ice load estimation for thin ice is unclear, particularly for local pressure estimation. This is in part due to the broader issue of having different recommended approaches for estimating local, global, and dynamic ice loads during level ice interactions with a given structure based on region, scenario type, and a variety of other conditions. It is essential from a design perspective that these three scenarios each be evaluated using appropriate definitions for local design areas, global interaction area, and other structural details. However, the need for use of different modeling approaches for ice loads associated with each of these scenarios is not based on ice mechanics but rather has largely evolved as a result of complexities in developing physics-based models of ice failure in combination with the need to achieve safe designs in the face of limited full-scale data and the need for implementation in a probabilistic framework that can be used for risk-based design assessments. During a given interaction, the ice is the same regardless of the design task at hand. In this paper, a new approach is proposed based on a probabilistic framework for modeling loads from individual high-pressure zones acting on local and global areas. The analysis presented herein considers the case of thin, first-year sea ice interacting with a bottom-founded structure based on an empirical high-pressure zone model derived from field measurements. Initial results indicate that this approach is promising for modeling local and global pressures.

The Dynamic Failure Behaviour of High-Pressure Zones during Medium-Scale Ice Indentation Tests

“…For many of the existing ice-structure interaction models [30][31][32], one of the primary difficulties lies in linking the model parameters with fundamental ice mechanics; however, incorporating the hpz failure mechanisms can address this limitation. Recent models of non-simultaneous ice failure [33,34] have been extended to account for the dynamic coupling effects described, providing promising new approaches for modelling dynamic ice-structure interaction processes of interest for offshore structure design.…”

A Framework for Integrating Life-Safety and Environmental Consequences into Conventional Arctic Shipping Risk Models

“…It is noted that while significant progress has been made in developing probabilistic ice load models to link vessels' ice exposure, extreme ice loads, and ice class selection [12][13][14][15][16], design aspects are outside the scope of the operationally focused work presented here.…”