PRR Project

Summary

1. TASKS TO BE ASSIGNED TO THE PROSPECTIVE EMPLOYEEThe science and technology activities (STA) in which the prospective employee will be involved include research and development (R&D) and science and technology services (STS) in the field of dynamic behaviour of concrete dams, concerning modelling and the safety of this type of structures. The main tasks to be accomplished are:a) Upgrade the current modelling capabilities of the dynamic behaviour of concrete dams research team, using existing state-of-the-art 3D numerical modelling, considering the non-linear behaviour of the system dam-foundation-reservoir under dynamic loading, in particular seismic actions. Explore the models, including monitoring data analysis.b) Improve the understanding of the prototype tests (forced vibrations and environmental tests) to assess the dynamic behaviour of concrete dams.c) Apply and develop techniques of Operational Modal Analysis (OMA) for dynamic Structural Health Monitoring (SHM) systems to predict changes of the dynamic behaviour and automatic damage detection.d) Integrate the team for the construction and testing up to failure of an innovative physical model of an arch dam with water in the LNEC’s 3D shaking table, subject to seismic actions.e) Participate in international working groups.f) Prepare research proposals and participate in national and international research projects.g) Publish papers with the research results.h) Train young researchers in MSc and PhD programs.2. SCIENTIFIC PROFILE REQUIREDGiven the tasks to be accomplished, the scientific profile required to the prospective employee should include:a) A PhD in Civil Engineering, with a strong background in structural dynamics.b) A background in numerical modelling for structural analysis using the finite element or the discrete element methods.c) Skills for experimental work, namely, in utilization, control and choice of test equipment, techniques for data treatment and interpretation of results, and similitude laws for physical scale models.d) Ability to analyse problems critically.e) Good teamwork skills in national and international environments.3. RATIONALE TO HIRE FOR THE SCIENTIFIC AREASince its founding, LNEC has been actively engaged in science and technology activities in dam engineering and currently continues to be a pioneer in the development of innovative methodologies in dam engineering. LNEC’s activities in this field have included research and development as well as science and technology services related to concrete dams and their foundations and abutments.LNEC has established itself as a reference in this field and receives continuous requests for services from government agencies and large owners of important concrete dams in Portugal and abroad.The existence, in the dynamic behaviour of concrete dams research team, of researchers with the adequate profile to accomplish the identified tasks is relevant for LNEC. Indeed, its role and responsibilities as provider of high-level science and technology services require continuous development of research to keep the high standards for which LNEC is known in this domain. It is, therefore, necessary to timely reinforce LNEC’s team and hire an Assistant Researcher.4. RELEVANCE OF THE SCIENTIFIC PROFILE OF THE PROPOSED POSITION IN THE CONTEXT OF THE STATE-OF-THE-ARTThe validation of numerical methodologies should be made by comparing numerical results with experimental data from prototype monitoring. However, when specific field data are not available, the simulation of different scenarios using physical scale models, respecting similitude laws, is very helpful. Laboratory tests in scale models have a large scope of application since they were the basis for the development and validation of numerical models. The hypotheses used in numerical simulations should be validated when dynamic loads and nonlinear material behaviour are considered. LNEC was pioneer in the use of scale models to perform failure studies of the dam body and the foundation for static loads considering nonlinear behaviour, and also to study the effects of dynamic loads on gravity dams and arch dams using shaking table tests. Also, scale models have been used to study the effects of earthquakes and cracking in the dam body, showing the versatility of such models to study damage in dams.There is a need of advanced numerical models to assess the safety of concrete and masonry dams in seismic regions, particularly for the case of older structures. Models should represent the dam-water dynamic interaction, the possibility of failure through the rock mass foundation and the effects of concrete deterioration. It is necessary to have: computationally efficient models for nonlinear time domain analysis; methods for expedite generation of complex dam-foundation-reservoir models; methods for interpretation of the dynamic response; validation of models against experimental and monitoring data.