Parallel Session A-1 - Mini-Symposium: Offshore geotechnics

* Effect of installation method and tool parameters on the lateral response of scaled piles in a laboratory environment. * Evolution of lateral stiffness with cyclic loading. * Effect of initial sand density on the lateral response of monopiles.

Upscaling of screw piles has been proposed for offshore use in foundations and anchors. This upscaling can result in a significant increase in installation vertical forces (crowd force). Subsequent research has show that this can be reduced and even eliminated by using over-flighting techniques (installation advancement ratio, AR < 1.0), which can also improve the in-service monotonic uplift performance. This study using centrifuge experiments and discrete element modelling investigates cyclic performance of a screw pile installed at varying AR. It is founded that reducing AR can improve uplift cyclic performance.

The main objectives of this paper are to: (1) establish the robust and efficient simple high strain dynamic testing (HSDT) requirements for validating displacement tapered piles capacities while exploring the installation effect; (2) determine a correlation between static and dynamic bearing capacity in compression for steel tapered piles installed by jacking in sand with various relative densities.

This research aims at investigating the influence of the installation method (namely impact and vibratory driving) on the soil properties around monopiles and how it affects the lateral response of such structures. In order to comprehensively understand the different phenomena involved, this problem is investigated through both numerical modeling and laboratory testing.

Offshore wind and marine renewable energy are rapidly increasing worldwide, with a clear trend towards deep waters and harsher marine environments. This poses significant engineering challenges, including the design of support structures and foundations. It is shown how advanced numerical modelling can guide the design of the foundations in chalk.

The Coupled-Eulerian-Lagrangian (CEL) method and the Material-Point-Method (MPM) are widely used in geotechnical engineering to model large deformations. They are compared by means of simulation of cone penetration tests in this work. Even though the agreement between the two methods is generally good, it is found that the CEL method performs worse because its results show significant oscillations that are not present in the simulations with the MPM.