This paper describes an implementation of the methodology, developed in Phase 2 the recent PISA (PIle Soil Analysis) joint industry research project, for the design of laterally-loaded monopiles in layered soils. The software PLAXIS MoDeTo and PLAXIS 3D are employed to obtain the soil reaction curves that are required for the method, following the PISA ‘numerical-based’ design approach. A particular design space is selected to define the variation of the geometrical parameters assigned to the three-dimensional (3D) Finite Element (FE) calibration models. The parameters that span the design space are the embedded length (L), the outer pile diameter (D), the pile wall thickness (t) and the height above the mudline (h), where the design load is applied. The soil reaction curves are determined from the 3D FE calibration models for separate homogeneous soil conditions consisting of stiff normally consolidated clay and very dense sand. The calibration set consists of eight 3D FE models, for each homogeneous soil profile. Subsequently, the soil reaction curves are parameterised and used to calibrate a one-dimensional (1D) FE model, formulated by means of Timoshenko beam theory, which allows for fast and robust design calculations. A final design model (DM) is defined and its response is studied considering the two homogeneous profiles and four additional layered soil profiles. The results of each 1D analysis are compared with equivalent 3D FE models and a 1D FE model developed at the University of Oxford (OxPile) as part of the PISA research. The accuracy metric eta (η) is used to compare quantitatively the response among the employed models, focusing on large displacements at ground level (about D/10). The results indicate a very good match for all considered soil profiles; all computed η values exceed 90%. The research findings support the applicability of the PISA design methodology in both homogeneous and layered soil conditions. @en

Finite Element Analysis of serviceability limit states (SLS) and bearing capacity (ULS) of piled foundations involves the modelling piles in the soil, including pile-soil interaction. Embedded beams are an efficient way to model multiple piles for complex practical applications. Following initial work of Sadek & Shahrour (2004) on embedded beam elements, Turello et al (2016a,b) introduced a new embedded beam formulation with interaction surface to overcome mesh-dependence and to improve the behaviour under lateral loading. The proposed paper describes an improvement and further evolution of the embedded beam with interaction surface for practical applications. The element has been implemented in the PLAXIS finite element software, compared with previous implementations and validated against pile load test data. The paper will show that the results of the new implementation are more accurate and less mesh-dependent than the previous implementation and the load-displacement performance is much closer to the actual pile response; both in axial loading and in lateral loading. @en

Future human spaceflight exploration missions to the Moon and beyond are hypothesised to benefit from human-robotic integrated operations. The European Space Agency focuses on preparing these operations, following the objective stated in the Global Exploration Roadmap of the International Space Exploration Coordination Group. Currently, human-robotic operations aim at technology development and demonstration, yet essential questions that remain unanswered are: How can human performance be measured, and which metrics are used? This contribution aims at answering this by preparing a pilot phase focusing on human performance assessment for subjects controlling a rover. A recent study by Hosseini (2016) for ESA identified essential knowledge gaps that must be filled to assess astronaut performance for tele-operations, which is of great importance for future missions since they affect mission planning, task allocation and even tool selection. In this regard, this study proposes follow-on research in which a tele-operations experiment is conducted by driving a rover, in order to evaluate human performance in tele-operations. In the previous study, two space-to-ground and multiple ground-to-ground tele-operations experiments were analysed in which subjects controlled a rover. Data analysis studied the command time and execution time of the assigned tasks, i.e. the time it takes for the human to give the command to the rover and the time it takes for the rover to execute its tasks, respectively. Results showed that the main challenge for performance assessment is the lack of recorded parameters. The logged data is limited only to time values and success/failure results and it does not specify performance variations. Furthermore, the study concludes that many different sub-tasks were performed in a limited amount of time, resulting in scarce data per sub-task and limiting the statistical significance. Follow-on research is proposed that aims at solving for the two above mentioned issues. Firstly, the study introduces parameters, which are used to assess the performance of pilots regarding neuro-ergonomics and human factors. Secondly, an experiment is set up and is tested for its rigidity in a protocol rehearsal, prior to performing the experiment with a relatively large group of participants. It is hypothesised that this approach has the potential not only to increase the qualitative assessment of the performance, but also to increase the quantitative results essential for preparing crew training and future missions.@en