To study characteristics of ice loads acting on offshore structures, we carried out various model tests in a small ice tank installed in a low temperature experimental room. First, ice modeling test on urea doped ice was conducted, and mechanical properties of the model ice were investigated. Then, penetration tests were conducted using cone models of various inclination angles and circular pile models of various diameters. To study the relation between global ice load and local ice load, penetration tests were also carried out using a divisible model consisting of five flat plates. From this study, we could grasp characteristics of global ice loads acting on cone type and circular pile type structures, and ice failure modes of respective structures. The measured values agreed well with the calculation results by the plastic limit analysis method by Ralston and the experimental data by other investigators. This shows that even model tests in a small ice tank can provide effective experimental results. The test results further made it clear that normalized local ice load is larger than normal-ized global ice load and, therefore, that grasping local ice load is important especially in wide structures having vertical walls.
