Caracterización multi-proceso de la operatividad portuaria
- Autores: Eva Romano Moreno
- Directores de la Tesis: Javier López Lara (dir. tes.), Gabriel Díaz Hernández (dir. tes.)
- Lectura: En la Universidad de Cantabria ( España ) en 2023
- Idioma: español
- Títulos paralelos:
- Multi-process characterization of port operability
- Tribunal Calificador de la Tesis: César Vidal Pascual (presid.), Rafael Molina Sánchez (secret.), Enrique Peña (voc.)
- Programa de doctorado: Programa de Doctorado en Ingeniería de Costas, Hidrobiología y Gestión de Sistemas Acuáticos por la Universidad de Cantabria
- Materias:
- Enlaces
- Tesis en acceso abierto en: UCrea
- Resumen
- español
En la línea de atraque, el desarrollo de las operaciones portuarias está condicionado por la respuesta del sistema de buque atracado bajo la acción de los forzamientos del clima meteo-oceanográfico en el muelle. Una adecuada caracterización de la cadena de procesos implicados es fundamental para una interpretación más completa y precisa de la operatividad portuaria y la parada operativa, basada en un entendimiento completo de la física del problema. El objetivo de esta tesis es desarrollar una metodología eficiente que permita avanzar hacia una caracterización multi-proceso y multivariable de la operatividad portuaria, basada en una descripción pormenorizada de los principales procesos involucrados, desde una definición precisa del clima de oleaje espectral en el exterior del puerto, una caracterización desagregada de la respuesta de agitación multimodal y su variabilidad espacial en el puerto, y la respuesta final del sistema de buque atracado en muelle.
- English
Today, shipping is of great importance for the global economy. Any disruption in the shipping industry has a major impact on the global supply chain, with consequent economic, social and environmental repercussions. Efficient operation of global transport and supply chains, in which ports are an indispensable element and loading and unloading operations play a crucial role, is essential. Therefore, efficient and well-planned port operations are required, capable to skillfully manage and address the changing trends and requirements expected in a challenging future of global trade.
The performance (efficiency and safety) of port operations at berths is strongly conditioned by the dynamic response of the berthed ship system induced by met-ocean forcing conditions. In this sense, the port operability can be limited by the effect of certain unfavorable conditions that cause excessive moored ship motions, even inducing downtime events. Traditionally, the port operability/downtime assessment is based on recommended exceedance thresholds of specific met-ocean conditions at berths and/or ship motion parameters, according to the type of ship and port activity. These operational thresholds are usually based on efficiency and safety criteria during port operations. A proper definition of the processes involved in the response of moored ship at berths is essential for a suitable characterization of the port operability. It is a chain of highly multivariate processes, with different actors and concomitant agents involved. The dynamic response of the berthed ships is induced from a reciprocal, multidimensional and site-dependent interaction of the local met-ocean forcings with the moored ship system and its environment. In turn, the local met-ocean forcings at berths are the result of a complex interaction of the outer-harbor met-ocean conditions with the harbor configuration. Going further, the met-ocean conditions in the vicinity of harbors result from different transformation and propagation processes that they undergo from their offshore generation. Therefore, due to the high dimensionality and case-dependence of the problem, comprehensive multivariate multi-process analyses are required for port operability assessment.
At this sense, this thesis presents methodological developments for a better assessment of port operability/downtime, based on a comprehensive historical characterization of the main sea-side processes involved, from offshore to in-port berthing areas. A quasi-holistic methodology is developed based on an advanced numerical modeling approach and statistical post-processing methods for an efficient assimilation of representative historical information, both of the multimodal wave agitation climate in harbors and of the final dynamic response of moored ships at berths. First, an accurate characterization of the multimodal spectral wave climate in the vicinity of harbors, and thus of the forcing of the wave agitation modeling, is achieved, based on a real-shaped wave spectra definition approach. By means of dynamic wave downscaling from offshore to near-port, the historical time series of hourly real-shaped directional spectra are generated at different positions, representing the spatial variability of outer-harbor wave climate in the study area when forcing the wave agitation model. An important uncertainty reduction due to the offshore wave climate definition in wave agitation modeling is achieved. Secondly, a disaggregated spectral-based characterization of the historical harbor wave agitation climate is attained. A detailed frequency-direction wave spectrum definition of hourly historical wave agitation patterns within harbor basins is achieved, providing an in-depth description of the whole multidirectional and multi-reflective wave patterns occurring as a natural harbor response, related to the outer-harbor spectral wave climate. This constitutes an advance from the monoparametric/aggregated wave height parameter-based approaches, typically used for wave agitation characterization, to a multivariate and disaggregated representation of in-port waves and the multiple wave penetration and transformation processes within harbor basins. In addition, the wave agitation spectral type concept is for the first time proposed, whereby the wave agitation spectral shapes are classified into clusters, representative of the historical wave agitation response in a harbor. In this way, the long-term and spatially variable wave agitation climate within harbor basins, in relation to the multimodal outer-harbor wave climate, is efficiently and comprehensively characterized. Third, a further step is taken towards an efficient characterization of the multi-variable response of moored ship systems, including ship motions and mooring line forces, related to both the historical outer- and in-port spectral wave climate. In doing so, a comprehensive description of the main sea-side processes involved is provided, from offshore to in-port local wave forcing agents, their multidimensional interaction with the port structures and the ship, to the final induced response of the moored ship system. A multi-process and multi-variable assessment of port operability/downtime and safety in harbors is provided, allowing the identification of specific wave climate and mooring conditions triggering downtime or unsafe situations, such as multiple line breakage, even though they may not appear to be the most problematic conditions in terms of wave agitation, as well as the suggestion of tailor-made mooring plans (among those analyzed) for each situation, while visualizing the operability/downtime and safety levels relative to each system response variable. At this point, it is noteworthy to highlight an important problem entailed in this task, related to the significant levels of uncertainty that may be associated with the numerical predictions of moored ship response, due to the usual lack of relevant information about the system (e.g., initial pretension, elasticity of new or used mooring lines, hysteresis in fenders, etc.). This problem is also addressed through a multi-variable optimization method to determine the most accurate numerical configuration for predicting the moored ship response from an extensive catalog. Additionally, further characterization capturing the time variability of moored ship motion amplitudes and periods over the duration of berthing events is proposed, suggesting moving forward from classical time-averaged monoparametric characterizations.
Finally, in the search of an efficient approach for practical applications of moored ship motion prediction, based solely on the available information (e.g., prototype measurement data from field campaigns, previously generated numerical/physical modeling-based datasets, etc.), a potential inference model based on machine learning techniques is presented. Based on a comparative performance evaluation of different artificial intelligence techniques for moored ship motion prediction, the highest-performing prediction model is identified. In addition, the simplicity and robustness of the proposed prediction model as opposed to the complexity demanded by other techniques, should be highlighted. From the proposed prediction model it is possible to obtain a global characterization of port operability and port downtime events, which can be used as an assisting tool for the planning and management of berthing and port operations in port terminals.
All the methodological developments presented in this thesis are described, applied and validated in real port areas. The numerical methodology is completely applied to the Africa basin, located in Las Palmas Port (Gran Canaria Island, Spain). A different study port (Outer Port of Punta Langosteira, A Coruña, Spain) is involved in the final part of the thesis devoted to the artificial intelligence-based prediction models, because of the availability of useful information for that purpose.
In conclusion, the improvements achieved towards a multivariate and multi-process characterization of port operability, based on a comprehensive description of the main maritime processes involved, from an accurate spectral definition of outer-harbor wave climate, a disaggregated characterization of multimodal and spatially variable wave agitation response, and the final dynamic response of moored ship systems at berths, can be relevant for many practical applications in harbors. A detailed and quasi-holistic perspective of the port operability/downtime is sought, leading to enhanced assessment and/or prediction of port efficiency, safety and operability/downtime levels at berths, both for historical characterization, analysis of current situation, and for future planning, management and forecasting; increasing accuracy for the design and/or optimization of the port environment; proposal of good practice standards to minimize operational downtime, etc.
- español
