The Pipeline Ice Risk Assessment & Mitigation JIP (PIRAM) developed aset of engineering models and design procedures for implementation intoindustry best practices for risk mitigation and protection of pipelineinfrastructure from ice keel loading. The models established the pipelinemechanical behaviour in response to ice keel load events, and assessedengineering concepts for protection and risk mitigation strategies. Improvedmethodologies for contact frequency and ice keel loads determination formedpart of the integrated model.
Pipeline protection against ice gouging is overviewed. A review of subgougeresponse and physical model tests provided a basis for refinement of threedimensional continuum finite element analyses of steady state gouging includingthe implementation of an effective stress based soil plasticity constitutiveroutine. A fully coupled ice, seabed and pipeline interaction model is used tocalibrate a simpler pipeline design approach for design purposes. Thestructural model, improved by considering 3D interaction effects, comparesstrains within the pipeline to those from continuum analyses and from physicalmodel tests. The PIRAM pipeline model provides the engine for the probabilisticassessment of pipeline cover depth using a GIS-based decision-support-systemfor route planning.