Estudio de la influencia de la rigidización longitudinal en vigas armadas de acero de canto variable bajo solicitaciones de cortante

[ANGLÈS] In steel construction is becoming increasingly common implementation of structures formed with very slender girders of varying depth to suit the design and cover large spans. The current regulations make no reference to the criteria to be followed during the design of variable depth girders. The criteria used are based on simplified models for beams of constant depth, regardless of the occurrence of certain phenomena which need not be decoupled (for example, instability of the soul, plasticizing and interaction with the bending). Following the line drawn in previous studies, this one tries to analyze the behavior of variable depth beams with longitudinal stiffeners (with different geometries) under the influence of shear stress. It will cover two aspects of this process modeling and implementation of an experimental campaign that will serve to test the validity of the model.[CASTELLÀ] En construcción metálica cada vez es más común la ejecución de estructuras conformadas con vigas armadas muy esbeltas y de canto variable para adaptarse al diseño y abarcar grandes luces. La actual normativa no hace referencia a los criterios que se deben seguir durante el proceso de dimensionamiento de vigas armadas de canto variable. Lo criterios que se utilizan se basan en modelos simplificados para vigas de canto constante, sin tener en cuenta la aparición de ciertos fenómenos que no tienen porqué estar desacoplados (por ejemplo, la inestabilidad del alma, la plastificación y la interacción con el flector). Siguiendo la línea trazada en estudios anteriores, en éste se pretende analizar el comportamiento de vigas de canto variable con rigidizadores longitudinales (con diferentes geometrías) bajo los efectos de esfuerzos cortantes. Se tratarán dos aspectos, la modelización de este proceso y la realización de una campaña experimental que servirá para contrastar la validez del modelo

Metodología para el análisis de rotura de presas con aterramiento mediante simulación con fondo móvil

Los estudios de rotura de presas permiten evaluar la peligrosidad y el riesgo por inundación asociado a un posible fallo de estas estructuras. La legislación y documentos técnicos vigentes en España marcan el camino a seguir para la correcta clasificación de la presa en función del riesgo potencial que supone para la sociedad, la economía y el medioambiente. Sin embargo, existe un vacío en las recomendaciones a seguir cuando la presa a clasificar se encuentra parcial o totalmente aterrada de sedimentos. El presente documento tiene por objeto presentar una metodología para afrontar estudios de rotura de presas aterradas mediante simulación numérica conjunta de la formación de la brecha y el transporte de sedimentos (fondo móvil). La aplicación de esta metodología a un caso de estudio real ha permitido observar cómo el hidrograma tras la rotura considerando fondo móvil es sensiblemente diferente al obtenido por la metodología estándar que considera fondo fijo dentro del vaso.Peer ReviewedPostprint (published version

Simulación de rotura de presas aterradas con fondo móvil: caso de estudio

Los estudios de rotura de presas han permitido conocer la peligrosidad y el riesgo de inundación asociado a un posible fallo de estas estructuras. La legislación y documentos técnicos vigentes en España marcan el camino a seguir para la correcta clasificación de la presa en función del riesgo potencial que supone para la sociedad, la economía y el medioambiente. Sin embargo, estos documentos no indican cómo proceder cuando la presa a clasificar se encuentra parcial o totalmente aterrada de sedimentos. El presente documento tiene por objeto presentar una nueva metodología para afrontar estudios de rotura de presas aterradas mediante un modelo numérico que permita, al mismo tiempo, simular la formación de la brecha y el transporte de sedimentos. Esta metodología ha sido aplicada a una presa en el río Llobregat (Gironella, España). Se ha podido observar cómo el hidrograma tras rotura es mayor cuando se considera el fondo móvilPostprint (published version

Experimental characterization and two-dimensional hydraulic-hydrologic modelling of the infiltration process through permeable pavements

Permeable pavements are a common solution for wearing course layers in roads and urban areas. They are composed by highly porous materials with permeability several orders of magnitude above of the natural terrain. This work presents, on one hand, the experimental characterisation of the hydraulic behaviour of a permeable asphalt concrete wearing course layer and, on the other hand, the development and validation of a two-dimensional coupled hydraulic-hydrological distributed numerical model to reproduce the effect of the infiltration in the rainfall-runoff transformation and in the overland flow propagation processes. Experiments show linear and potential trends for permeability-hydraulic head relations when considering constant and variable hydraulic heads, respectively, reaching permeability up to 0.04 m/s for 1 m of hydraulic head. Experiments are reproduced numerically by incorporating new infiltration formulas, which consider the infiltration rate as a function of the hydraulic head, and a specific numerical scheme for properly dealing the mass conservation when negative values of the water depth may occur numerically due to high infiltration rates. This two-dimensional coupled hydraulic-hydrological distributed numerical model is a validated tool for simulating the effect of permeable pavements not only in the rainfall-runoff process, but also for the overland flow propagation.Peer ReviewedPostprint (published version

Evaluation of two hydro-meteorological ensemble strategies for flash flood forecasting over a catchment of the eastern Pyrenees

This study aims at evaluating the performances of flash flood forecasts issued from deterministic and ensemble meteorological prognostic systems. The hydro-meteorological modeling chain includes the Weather Research and Forecasting model (WRF) forcing the rainfall-runoff model MARINE dedicated to flash flood. Two distinct ensemble prediction systems accounting for (i) perturbed initial and lateral boundary conditions of the meteorological state and (ii) mesoscale model physical parameterizations, have been implemented on the Agly catchment of the Eastern Pyrenees with three sub-catchments exhibiting different rainfall regimes. Different evaluations of the performance of the hydro-meteorological strategies have been performed: (i) verification of short-range ensemble prediction systems and corresponding stream flow forecasts, for a better understanding of how forecasts behave, (ii) usual measures derived from a contingency table approach, to test an alert threshold exceedance, and (iii) overall evaluation of the hydro-meteorological chain using the Continuous Rank Probability Score, for a general quantification of the ensemble performances. Results show that the overall discharge forecast is improved by both ensemble strategies with respect to the deterministic forecast. Threshold exceedance detections for flood warning also benefit from large hydro-meteorological ensemble spread. There are no substantial differences between both ensemble strategies on these test cases in terms both of the issuance of flood warnings and the overall performances, suggesting that both sources of external-scale uncertainty are important to take into account

Iber applications basic guide: Two-dimensional modelling of free surface shallow water flows

[Abstract] Iber is a software package for simulating unsteady free-surface turbulent flow and transport processes in shallow water flows. This is a basic tutorial of Iber, aimed at new users who want to acquire a basic knowledge of the software. It is not intended to cover all the software’s capabilities, but rather to give a flavour of the typical applications of Iber and its main elements, so that new users can evaluate whether the software is appropriate for their needs.CONTENTS: 1. Introduction; 2. IBER; 3. Practical example 1: Street intersection; 4. Practical example 2: River flood inundation; 5. Practical example 3: Bridges and culverts; 6. Practical example 4: Dam break; 7. Practical example 5: Sediment transport: bedload; 8. Practical example 6: Wastewater discharge of CBOD and ammonia in a river; 9. Practical example 7: Sewage spill in an estuary

Design of Drainage Downspouts Systems over a Road Embankment

[EN] Numerous studies have examined the complex relationship between factors like embankment downspout spacing, height, slope, and rainfall characteristics in the quest to find the best spacing for embankment downspouts. Defining the correct spacing between road drainage elements is of utmost importance in minimizing water flow on roadways. This paper presents a methodology based on numerical methods for the design of road drainage systems using the Iber model. The objective of the work is to propose a tool and criteria for analyzing the hydraulic behavior of runoff on highways, determine the appropriate drainage behavior, and apply the methodology in a case study. This case study is based on a straight highway section with slopes up to 5%, according to Spanish road design regulations. Different dimensions are considered for the chute, drainage channel, collection nozzle, and downspout over the embankment. Tests are carried out to evaluate the separation between downspouts, the longitudinal slope, and the size of the nozzles. The results show the suitable hydraulic performance of the model, besides providing the absorption capacity of each downspout. The influence of the nozzle size, the slope, and the width of the causeway on the draughts and velocities is analyzed. The influence of downspout spacing and nozzle type on road drainage design is determined. In summary, this article presents a methodology and criteria for the design of road drainage systems and shows the results obtained in a case study using the Iber model. The results help in understanding the influence of different variables on the hydraulic behavior of road runoff and provide relevant information for proper drainage design.Aranda Domingo, JÁ.; Sánchez-Juny, M.; Sanz-Ramos, M.; Beneyto, C. (2023). Design of Drainage Downspouts Systems over a Road Embankment. Water. 15(20):1-19. https://doi.org/10.3390/w15203529119152

A CUDA Fortran GPU-parallelised hydrodynamic tool for high-resolution and long-term eco-hydraulic modelling

Eco-hydraulic models are wide extended tools to assess physical habitat suitability on aquatic environments. Currently, the application of these tools is limited to short river stretches and steady flow simulations. However, this limitation can be overcome with the application of a high-performance computing technique: graphics processing unit (GPU) computing. R-Iber is a GPU-based hydrodynamic code parallelised in CUDA Fortran that, with the integration of a physical habitat module, performs as an eco-hydraulic numerical tool. R-Iber was validated and applied to real cases by using an optimised instream flow incremental methodology in long river reaches and long-term simulations. R-Iber reduces the computation time considerably, reaching speed-ups of two orders of magnitude compared to traditional computing. R-Iber allows for overcoming the current limitations of the eco-hydraulic tools with the simulation of high-resolution numerical models calculated in a reasonable computation timeframe, which provides a better representation of the hydrodynamics and the physical habitat.The contract of the D.D.-S. is funded by the International Center for Numerical Methods in Engineering (VAC-2021-1).Peer ReviewedPostprint (published version

Desarrollo de una herramienta para simular obstrucciones en flujos con Iber

Los modelos de simulación hidráulica en lámina libre han supuesto un revulsivo para el análisis de inundaciones, entre otros. Su evolución está permitiendo realizar simulaciones cada vez más complejas, y por ende más realistas, a pesar de las simplificaciones que han sido necesarias para la obtención de las ecuaciones que gobiernan el flujo. La consideración de obstrucciones al flujo tales como vegetación, vehículos, etc., puede ser tratado de diferentes maneras (aumento de la rugosidad, secciones equivalentes, etc.). En este trabajo se presenta una nueva herramienta en Iber que permite simular obstrucciones al flujo considerando el porcentaje de obstrucción que suponen respecto a la sección completa. Se ha testado la herramienta mediante casos teóricos y reales con buenos resultados.Postprint (published version

A machine learning-based surrogate model for the identification of risk zones due to off-stream reservoir failure

Approximately 70,000 Spanish off-stream reservoirs, many of them irrigation ponds, need to be evaluated in terms of their potential hazard to comply with the new national Regulation of the Hydraulic Public Domain. This requires a great engineering effort to evaluate different scenarios with two-dimensional hydraulic models, for which many owners lack the necessary resources. This work presents a simplified methodology based on machine learning to identify risk zones at any point in the vicinity of an off-stream reservoir without the need to elaborate and run full two-dimensional hydraulic models. A predictive model based on random forest was created from datasets including the results of synthetic cases computed with an automatic tool based on the two-dimensional numerical software Iber. Once fitted, the model provided an estimate on the potential hazard considering the physical characteristics of the structure, the surrounding terrain and the vulnerable locations. Two approaches were compared for balancing the dataset: the synthetic minority oversampling and the random undersampling. Results from the random forest model adjusted with the random undersampling technique showed to be useful for the estimation of risk zones. On a real application test the simplified method achieved 91% accuracy.This work was partially funded by the Spanish Ministry of Science, Innovation and Universities through the Projects ACROPOLIS (RTC2019-007343-5), TRISTAN (RTI2018-094785-B-I00) and DOLMEN (PID2021-122661OB-I00), as well as by the Spanish Ministry of Economy and Competitiveness, through the “Severo Ochoa Programme for Centres of Excellence in R & D” (CEX2018-000797-S), and by the Generalitat de Catalunya through the CERCA Program.Peer ReviewedPostprint (published version