Dr. Lars Andresen (left) receiving a golden apple from Geotechnical Group Chair Walter Papp at the end of the GZA Lecture.

Dr. Andresen presented methods that are primarily applicable to the design of offshore energy structures, such as oil platforms and wind turbines. In addition to static loads from the usual sources, these structures are typically subjected to dynamic loads from waves, ice, as well as earthquakes. He explained the key features of different types of foundations, including suction anchors, torpedo anchors, jacket with skirted foundations, gravity base structures, etc. and showed examples of how Finite Element Analyses (FEA) have been used to design such structures. Cyclic shear strengths of soil are a key input parameter for foundation design of offshore structures. Dr. Andresen showed results of cyclic direct shear tests conducted at NGI that are used in the FEA analyses.

Dr. Andresen closed his presentation with his remarks and challenges related to foundation design for offshore structures. He remarked that 3-D FEA was becoming the standard and there was a growing need for quality control of analyses. According to him, it was important to model remolding of soil due to large deformation conditions.

Photo and summary by Anirban De