Abstract
This paper considers geotechnical site investigations for offshore structures in chalk areas of the North Sea and the Baltie Sea. Chalk is a soft limestone rock. its engineering behavior may be idealized as for most other rock types. High-level comments are provided on applicability of offshore geotechnical investigation methods for chalk. Significant judgement will remain for characterization of discontinuous rock behavior. Offshore structures in these chalk areas will mostly include support structures resisting high cyclic VHMT actions (Vertical, Horizontal, Moment, Torsion). A case study for low density chalk illustrates opportunities and challenges for a steel jacket structure subject to high cyclic VHM actions.