Browsing by Autor "Juan Saldarriaga"

Now showing 1 - 20 of 31

Advanced Geometrical Analysis of Water Distribution Networks (WDNs): A Comparison between Standard and Minimum Capital-Cost Designs
(2021) Juan Carvajal; Andrés Ariza; Juan Saldarriaga
Different researchers have comprehensively addressed the water distribution network (WDN) optimization design problem in the past years. However, in the analysis of the optimized WDN, the relationship between the geometric parameters of the network and the hydraulic parameters obtained from the optimal design has been set aside. In this research, a robust geometric analysis of optimal WDN designs by pipe cost minimization is made in order to provide a response to the possible relationships between the geometry of the network and its optimized design. In addition, geometrical analysis is performed understanding that water distribution infrastructure, represented as a spatially organized graph, is a complex network of interconnected vertices (nodes) and edges (pipes) that belong to the emerging topic of complex network theory (CNT). Therefore, CNT metrics along with other geometric aspects (e.g., pipe diameter, pipe length, fractality, branch index, among others) of the network are measured for analyzing features of the physical domain where hydraulics and optimization occurs. As a result, it was determined how the effectiveness and efficiency of optimization methodologies are affected depending on the network topology.
Algorithms of Combinatorial Optimization for the design of water distribution networks
(2005) Germán Villalba Fernández de Castro; Juan Saldarriaga
Algoritmos de Optimización Combinatoria (AOC) aplicados al diseño de redes de distribución de agua potable
(Universidad de Los Andes, 2005) Germán Villalba Fernández de Castro; Juan Saldarriaga
The ACO are methodologies to find an approximation to least cost design of water distribution network. REDES and EPANET are used for hydraulic simulation and well known problems are solved finding solutions of less cost satisfying pressure constraints. This methodology is computationally much faster when compared with other algorithms used previously to solve this problem and good solution can be found. Furthermore is possible to optimize known solutions to find better solutions. The Hanoi network problem is tested and better solutions were found than those published previously in the literature.
Analysis of Fractality in Water Distribution Networks Using Hydraulic Criteria
(2019) Kevin Vargas; Juan Saldarriaga
The fractal dimension in water distribution networks (WDN) can be seen as an indicator or a scaling factor of how much the network changes topologically, according to the scale in which it is analyzed. The fractal dimension of a considerable number of networks with different characteristics was calculated in order to study its behavior and have a better understanding of this feature. Three different criteria were used to calculate the weight of each node in the box covering algorithm used to determine the fractal dimension: topology, SumQ, and HGL*SumQ. All of the studied networks resulted to be fractal networks since the coefficient of determination (R2) of the linear fit after applying the box covering algorithm was always above 0.95. The largest values for the fractal dimension were obtained with the topology weight criterion. There was not a clear tendency in the variation of fractal dimension when modifying the networks’ demands and calculating the weights with the proposed hydraulic criteria (SumQ and HGL*SumQ).
Annlisis SIG de caracterrsticas topollgicas e hidrrulicas vs. densidad poblacional en Redes de Distribuciin de Agua Potable Caso de estudio en la ciudad de Bogott, Colombia (GIS Analysis of Topology and Hydraulic Characteristics vs. Population Density in Water Distribution Networks Study Case in Bogott City, Colombia)
(RELX Group (Netherlands), 2017) Andres C. Salazar; Juan Saldarriaga; Laura Carolina Vega Piña
Assessment of Criteria to Make Topological Changes in Water Distribution Systems under Future Water Demand Scenarios
(2018) Juan Saldarriaga; Laura C. Vega
Population growth is one of the most challenging factors around the design, operation, and renewal of water distribution systems (WDS). Nowadays, cities are subjected to many dramatic changes that may disturb the performance and original approach of urban infrastructure; among these are the informal settlements (slums) and overcrowding phenomena. This paper describes a rehabilitation methodology of real WDS that seeks to identify the proper topology changes, in terms of pipes replacement, under different demand scenarios in order to readjust the network, achieve minimum pressure requirement, and improve the hydraulic performance of the whole system. This research focuses in the assessment of two rehabilitation criteria, tested in two WDSs of different Colombian towns and three district metering area (DMA) of main Colombian cities, with an infrastructure installed at least twenty years ago. Some surrogate measures of networks reliability were taken into account to assess the rehabilitation methodology, and its results were compared with optimal designs. The EPANET toolkit, MATLAB, and REDES software were used in this research. Both criteria proved to be. Both criteria proved to be good benchmarks to improve some performance indicators in each rehabilitated network. Finally, the suitability of each criteria was analysed considering the topologic complexity as well as network capital cost.
Battle of the Water Networks District Metered Areas
(American Society of Civil Engineers, 2019) Juan Saldarriaga; Jessica Bohórquez; David Celeita; Laura Vega; D. Páez; Dragan Savić; Graeme C. Dandy; Yves Filion; Walter M. Grayman; Zoran Kapelan
The Battle of Water Networks District Metered Areas (BWNDMA) was the latest of the Battle of Water Networks competition series held at the 18th Water Distribution Systems Analysis Conference (WDSA 2016) as part of ASCE’s Environmental and Water Resources Institute (EWRI) stand-alone conferences in Cartagena, Colombia in July 2016. In these competitions, the main objective was to address a specific problem related to water distribution systems (WDS) regarding how to optimize the design and operation of the system’s main components. This time, the competition was focused on the challenge of WDS network sectorization, that is, determination of the new district metered areas (DMAs) for an existing network. Design requirements involved constraints related to costs, pressure uniformity, and water quality. Changes in valve and pump operations were needed to supply demands at adequate pressures and acceptable water quality for the given supply scenarios: a wet season and a dry season with water shortages. Seven teams from different parts of the world participated in the BWNDMA and presented their solutions at a special session during the 18th WDSA. This article summarizes the BWNDMA teams’ approaches, outcomes, and learned lessons for solving the challenging stated problem. An analysis of some of the decisions that were taken is presented; for instance, some teams ignored the demand similarity criterion, the water age criterion, the pressure restrictions, or the constraints in the water rate that could be extracted from sources. The approaches developed in the BWNDMA represent the state-of-the-art with respect to the analysis of hydraulic conditions in DMAs of real-world water distribution networks for which it is mandatory to make efficient use of available water resources.
Biofilm behavior after successive washes in water pipes under pressure
(2005) Paula Reyes del Toro; Juan Saldarriaga
Cadastral Misinformation and Its Effects on the Hydraulic Behavior of Water Distribution Networks and Their Models Calibration
(2008) Juan Saldarriaga; Daniel Rodríguez
This article presents the results of a theoretical research on the effects cadastral misinformation on the simulation and calibration of Water Distribution Networks (WDN). It describes the developed methodology used to determine the effect that these mistakes have on the hydraulic response and calibration WDN models. Those effects were evaluated both for important pipes and different sets of unimportant pipes from the hydraulic point of view. The research proved that the Resilience Index is directly proportional to the effect produced by a mistake. In addition, the calibration methodology developed could be used to locate the cadastral mistakes. This means the hydraulic model could be used as a tool to improve water utilities WDN management. Finally, the methodology validated the use of skeletonized models.
Comparaciin entre diseeos optimizados y diseeos reales en Redes de Distribuciin de Agua Potable. Efecto del Aumento de la poblaciin a lo largo de la vida til del proyecto (Comparison between Optimal and Real Design in Water Distribution Systems (WDS). Effect of Population Growth During the Project Lifespan)
(RELX Group (Netherlands), 2017) Alejandra Posada; Juliana Robles; Jessica Bohórquez; Juan Saldarriaga
Comparación de metodologías de localización óptima de tanques de tormenta considerando Cambio Climático. Casos de estudio: Bogotá y Medellín, Colombia
(IWA Publishing, 2022) Laura J. Enríquez; Laura Pulgarín; Jorge A. Garzón; Danna Velásquez; Juan Saldarriaga
La impermeabilización del suelo debida al crecimiento urbano implica un cambio en las condiciones hidrológicas locales; adicionalmente, se espera que el Cambio Climático genere un incremento en la frecuencia de periodos intensos de lluvia en algunas regiones. Para evitar sobrecargas en los sistemas de drenaje urbano se ha propuesto el uso de tanques de tormenta para el almacenamiento temporal de agua. De esta forma, el presente trabajo busca evaluar y comparar el desempeño de dos metodologías de localización óptima de tanques de tormenta bajo escenarios de precipitación que consideran los efectos del Cambio Climático en dos ciudades de Colombia. Las metodologías usadas fueron OptSU y OptiTank, donde la primera incluye un control hidráulico y la segunda no. Así, se verificó que ambos métodos lograron reducciones mayores al 60% en las inundaciones. Asimismo, se encontró que OptSU presenta mejor desempeño en redes de alta pendiente, mientras que OptiTank tiene buenos resultados para cualquier pendiente.
Diferencias en el tratamiento de la ecuaciin de continuidad para nudos en carga en EPA-SWMM (Effect of Different Treatment of Continuity Equation in Nodes for Surcharging and Flooding Simulation in SWMM)
(RELX Group (Netherlands), 2017) F. Javier Martínez-Solano; Pedro L. Iglesias‐Rey; Juan Saldarriaga; Vicente S. Fuertes-Miquel
Diseeo optimizado de redes de distribuciin de agua potable (Programa REDES) (Optimized Design of Water Distribution Networks (Software REDES))
(RELX Group (Netherlands), 2017) Juan Saldarriaga; L. López; D. Páez; Daniel Stalin Viteri Luna; Sebastián González Hernandez
Effects of adherence in the drying of brewer’s spent grain with rotating equipment
(Research Square (United States), 2023) Guilherme Henrique Alves Pinto; José Teixeira Freire; Flávio Bentes Freire; Juan Saldarriaga; Fábio Bentes Freire
Abstract Brewer's spent grain (BSG) is a biomass with a high lignocellulosic content that can be reused in thermal processes, however it has high moisture content, which avoids it from being used in these processes. Pretreatment by drying rotating equipment turns out to be a suitable alternative. This work studied the rotational drying of BSG analyzing the effects of adhesion of solids. To do this, a standard pan combined with an external blower was chosen as a rotary dryer due to the easy access to the bed and the inner surface of the dryer. In addition, this type of dryer made possible to determine the relationship between BSG moisture and adhesion force. Under the operating conditions of the experiments, the moisture content of BSG decreased from 80 to 8.6% (wb), making it possible for the biomass to be utilized in thermal processes. Moisture ratios higher than 0.6 led to greater adherence and consequent agglomeration of solids, reducing their mobility and heat transfer with the internal surface of the dryer. At the start of drying, the bed’s rotational speed rate of BSG was approximately 14 rpm, half of the maximum rate of 28 rpm, also the temperatures of the BSG and the inner wall of the tray were in equilibrium, showing that changes in biomass adhesion would take non-uniform drying.
Effects of Minimum Cost Optimization in Water Distribution Networks on Residual Chlorine and Trihalomethanes Dynamics
(American Society of Civil Engineers, 2025) Laura González; Sergio Martín Vicente Serrano; Valeria Rodríguez; Daniel Álvarez; María Alejandra González; Jaime Plazas‐Tuttle; Daniele Laucelli; Juan Saldarriaga
Water distribution networks (WDNs) are designed under parameters and restrictions that guarantee compliance with hydraulic and water quality conditions in the system. The optimized design of WDNs ensures a lower cost for the network, maintaining an adequate supply of the demand. The optimization process leads to the reduction of some diameters compared with those in nonoptimal networks, thus changing the hydraulic behavior and hence affecting the water quality performance. This study aims to evaluate the relationship between optimal and nonoptimal WDN designs concerning residual chlorine levels and the formation of disinfection byproducts, specifically total trihalomethanes (TTHMs). Seventeen networks were optimized using the optimal power use surface, and for each one of them four nonoptimal alternatives were generated using genetic algorithms. Residual chlorine and TTHM concentrations were analyzed in the different configurations of the networks according to their geometrical characteristics. Results indicate that optimized networks exhibit reduced chlorine consumption, consequently leading to lower TTHM formation. In particular, the optimized design achieved a reduction of up to 20.6% in chlorine consumption compared to the more expensive alternative. Future work will focus on evaluating water quality dynamics, considering event-based operational changes.
Estudio en montaje ffsico del flujo cuasicrrtico en tuberras de alcantarillado fluyendo Parcialmente Llenas (Study of the Quasi Critical Flow in Partially-Full Sewer Pipes Using an Experimental Model)
(RELX Group (Netherlands), 2017) Christian Vásquez; Juan Saldarriaga; Juan Sebastián Rocha
Generation of Virtual WDS to Complete Cadastral Information of Existing Systems
(2018) Juliana Robles; Juan Saldarriaga
Information related to water distribution systems (WDS) in small and intermediate cities often may be incomplete or unreliable, and data acquisition may be infeasible due to elevated time and economic costs. This lack of information can lead to inaccurate network operation and maintenance, and it can also limit the use of calibrated hydraulic models to support future designs in the system. Virtual case studies can thus be treated and used to overcome the insufficient data problems. The results are not case-specific as the obtained with benchmark networks. This paper aims to evaluate a new methodology by generating virtual networks for different cities in Colombia and then comparing resulting virtual WDS with the real systems, based on data obtained from water utilities. For both sets, network layout similarity and hydraulic factors were analysed. The results of the comparison between real and virtual networks make it possible to conclude about the applicability and limitation of this virtual generation software in small cities or DMAs in large cities, and also allows suggesting alternative solutions.
Implementación de herramientas computacionales para el diseño de redes de distribución de agua potable y de drenaje urbano
(2022) Eliana Patricia González Puello; Laura Serje Martínez; Juan Saldarriaga
En los últimos años se ha visto un notorio incremento en la implementación de herramientas computacionales como apoyo en el diseño de sistemas de acueducto y alcantarillados, tanto a nivel empresarial, como en el proceso de formación de futuros diseñadores. Estas herramientas son de suma importancia en cursos relacionados con el diseño de sistemas de drenaje urbano y de distribución de agua, ya que, no solo permiten optimizar los costos de estas redes, sino también permiten obtener gráficos e incluso, videoclips mostrando el futuro funcionamiento del sistema. Atendiendo lo anterior, el Centro de Investigación en Acueductos y Alcantarillados-CIACUA de la Universidad de los Andes, ha desarrollado dos herramientas. En primer lugar, el software REDES, enfocado en el diseño optimizado de redes complejas de distribución de agua potable, a partir de cinco metodologías de diseño y la segunda herramienta, UTOPÍA, centrada en el diseño optimizado de redes de drenaje urbano teniendo en cuenta la minimización de los costos, y no menos importante, se cuenta con varios programas, incluidos en el libro Hidráulica de Tuberías del ingeniero Juan Saldarriaga. Con el fin de probar el rendimiento del programa UTOPÍA, se realizaron varias pruebas con diferentes casos de estudio y softwares similares, donde se ha obtenido un costo inferior al reportado en la literatura técnica; mientras que, el programa REDES se ha utilizado para dar solución a problemáticas relacionadas con RDAP, e incluso, se han generado propuestas enfocadas a la modificación de módulos que mejoren y aumenten la aplicabilidad del software en variadas situaciones obteniendo resultados satisfactorios. Lo anterior lleva a concluir que en la actualidad se ha vuelto imprescindible el desarrollo de capacidades relacionadas con el uso de herramientas computacionales que faciliten el proceso de aprendizaje y mejoren los resultados obtenidos para un diseño de acueducto/alcantarillado.
Localización de puntos de monitoreo de calidad de agua en sistemas de distribución
(2014) Juan Saldarriaga; María Ximena Hernández; Cesar Prieto; Mauricio Jurado; Sara Gacharná; D. Páez
"Durante años, particularmente en los países en desarrollo, las empresas prestadoras del servicio (EPS) de agua potable han utilizado procedimientos empíricos para localizar, en sus redes de distribución, los puntos en los cuales deben hacerse muestreos periódicos, a fin de garantizar que cumplen con los estándares mínimos de calidad de agua. A pesar de que hoy en día estas empresas cuentan con excelentes herramientas informáticas para modelar la dinámica del agua en las redes, así como la evolución de la calidad de agua, no se tienen suficientes datos que permitan escoger en forma científica dichos puntos. En particular, no se cuenta con los coeficientes de decaimiento del cloro tanto de cuerpo como de pared. A pesar de esta limitación, se han desarrollado e implementado metodologías con el objetivo de diseñar redes de sensores que garanticen un constante monitoreo de la calidad del agua en los sistemas de distribución, pero que implican una alta incertidumbre. En la investigación objeto de este artículo se desarrolló una metodología que permitiera en ese ambiente de pocos datos escoger los puntos de monitoreo de calidad (PMC) de agua que respondieran simultáneamente a dos problemas típicos de las redes de distribución: por un lado, se buscaba garantizar la calidad del agua, medida por un residual de cloro, haciendo uso de un software desarrollado para este estudio; por otro lado, detectar problemas de coloración del agua (fenómeno por el cual el agua que llega a un conjunto de usuarios tiene un color diferente al transparente, afectando la percepción de calidad por parte de dichos usuarios) debido al desprendimiento de biopelículas, haciendo uso del programa TEVA-SPOT (Berry et al ., 2008). Este último enfoque puede desarrollarse bajo la optimización de múltiples funciones objetivo, según el tipo de protección que se desee garantizar, contra los eventos de coloración. La nueva metodología fue aplicada exitosamente en los 37 sectores hidráulicos en los que se encuentra dividida la red de agua potable de la ciudad de Bogotá, Colombia (aproximadamente ocho millones de habitantes). Finalmente, aunque el estudio se realizó para los 37 sectores, se tomó, a manera de ejemplo para este documento, uno de estos sectores como red tipo. Los resultados evidencian que ambas metodologías son confiables y que el diseño de la red de sensores depende del objetivo que se busque optimizar."
Medidas de protección contra la socavación local en pilas de puente
(Universidad de Los Andes, 1999) Francisco Plata; Chandra Nalluri; Juan Saldarriaga
The purpose of this present research is to analyze the effect of some protective structures used against local scour at bridge piers. The effects of using flat plates of different geometric shapes are studied. Experiments demonstrated that the efficacy of the tested elements increases when these are installed at the same level as the bed, as well as when their shapes conform to the patterns of scour basin around the pier. The maximum depth of scour in the presence of protective structures is found on the sides of the pier at a distance from it.