Impact of the Economic Recession on Toll Highway Concessions in Spain

After joining the European Union in 1986, Spain experienced steady economic growth that enabled the country to grow at a greater pace than other European countries. During this period, the government of Spain opted for major investments in public infrastructure by taking advantage both of the funding provided by the European Union and of several types of public-private-partnership (PPP) approaches. Within this framework, the government of Spain between 1996 and 2004 procured a series of toll highway concessions. These concessions entered into operation a few years before the global economic recession made itself felt in Spain. The concession contracts signed between the government and some private consortia allocated most of the risks (expropriation, construction, and traffic) to the private sector. In this paper the impact that the economic recession has had on the business performance of the concessionaires is assessed, and the effectiveness of the measures adopted by the government to help the concessionaire to avoid bankruptcy is analyzed. It was found that some of the guarantees offered by the legal framework to the concessionaires in case of bankruptcy are prompting an outcome that could negatively affect the users. In addition to that, some suggestions as to how to better allocate risk in toll highway concessions in the future are provided.

Traffic uncertainty in toll motorway concessions in Spain

This study assessed the inaccuracy of the traffic estimates for toll motorway concessions in Spain. It was found that the estimates conducted by both the government and the concessionaire showed a significant bias towards overestimating traffic. The level of overestimation in Spain is even greater than that reported by other studies based on worldwide data. The notorious levels of overestimation entail severe burdens to the economics of the concessionaires that often prompt renegotiations of the contracts, which are often accepted by the government. These renegotiations usually end up with toll changes or extension of the concession terms, which have to be ultimately borne by future motorway users. It is postulated herein that the bias towards overestimating traffic in toll motorways in Spain is mostly caused by strategic issues rather than by modelling errors.

Implantación de nuevos sistemas electrónicos de cobro de peaje en España

El sistema de cobro de peaje de las principales autopistas españolas únicamente posibilita que los usuarios realicen el pago de la tarifa del peaje, en el mejor de los casos ralentizando la marcha de sus vehículos, u obligándoles a parar en las playas de peaje. Este artículo hace un recorrido de los distintos sistemas de cobro de peaje existentes, analizando la perspectiva técnica y legal. Como consecuencia, se realizan una serie de recomendaciones que posibiliten la implantación del free flow como sistema de cobro electrónico de peaje referente en España; aprovechando las ventajas que este novedoso sistema ofrece.

Efficiency and spatial equity impacts of high-speed rail extensions in urban areas

Urban areas benefit from significant improvements in accessibility when a new high speed rail (HSR) project is built. These improvements, which are due mainly to a rise in efficiency, produce locational advantagesand increase the attractiveness of these cities, thereby possibly enhancing their competitivenessand economic growth. However, there may be equity issues at stake, as the main accessibility benefits are primarily concentrated in urban areas with a HSR station, whereas other locations obtain only limited benefits. HSR extensions may contribute to an increase in spatial imbalance and lead to more polarized patterns of spatial development. Procedures for assessing the spatial impacts of HSR must therefore follow a twofold approach which addresses issues of both efficiency and equity. This analysis can be made by jointly assessing both the magnitude and distribution of the accessibility improvements deriving from a HSR project. This paper describes an assessment methodology for HSR projects which follows this twofold approach. The procedure uses spatial impact analysis techniques and is based on the computation of accessibility indicators, supported by a Geographical Information System (GIS). Efficiency impacts are assessed in terms of the improvements in accessibility resulting from the HSR project, with a focus on major urban areas; and spatial equity implications are derived from changes in the distribution of accessibility values among these urban agglomerations.

Nueva pasarela peatonal en Móstoles sobre la autovía A5

El presente Proyecto de Construcción se enmarca dentro de las labores de urbanización del sector 5 de Móstoles, y que incluye la Construcción del Nuevo hospital (convirtiendo a Móstoles en el segundo municipio de Madrid con dos hospitales, después de la ciudad de Madrid), del Parque Científico Móstoles Tecnológico y de un recorrido peatonal que discurre entre ambas infraestructuras y la Universidad existente (Universidad Rey Juan Carlos de Móstoles). La construcción del recorrido peatonal cuenta con el problema de la existencia, entre el Hospital y el Parque Científico, de la Autovía del Suroeste A-5, que crea un importante efecto barrera a la comunicación entre ambas infraestructuras. Como solución a este problema, el presente Proyecto propone la construcción de una estructura que permita el paso de los peatones desde el Parque Científico hasta el Hospital y viceversa, y que a la vez permita mitigar el efecto barrera producido por la Autovía.

Viaducto sobre el río Irati

En este documento se describe de manera resumida el proceso seguido para la redacción del proyecto de construcción del Viaducto sobre el río Irati, en la autovía del Pirineo A-21, tramo Venta de Judas - Yesa (en el término municipal de Liédana, Navarra).

Improving probabilistic flood forecasting through a data assimilation scheme based on genetic programming

Opportunities offered by high performance computing provide a significant degree of promise in the enhancement of the performance of real-time flood forecasting systems. In this paper, a real-time framework for probabilistic flood forecasting through data assimilation is presented. The distributed rainfall-runoff real-time interactive basin simulator (RIBS) model is selected to simulate the hydrological process in the basin. Although the RIBS model is deterministic, it is run in a probabilistic way through the results of calibration developed in a previous work performed by the authors that identifies the probability distribution functions that best characterise the most relevant model parameters. Adaptive techniques improve the result of flood forecasts because the model can be adapted to observations in real time as new information is available. The new adaptive forecast model based on genetic programming as a data assimilation technique is compared with the previously developed flood forecast model based on the calibration results. Both models are probabilistic as they generate an ensemble of hydrographs, taking the different uncertainties inherent in any forecast process into account. The Manzanares River basin was selected as a case study, with the process being computationally intensive as it requires simulation of many replicas of the ensemble in real time.

Meteocean Influence on Inland and Coastal Floods in the East of Spain

The Santa Irene flood, at the end of October 1982, is one of the most dramatically and widely reported flood events in Spain. Its renown is mainly attributable to the collapse of the Tous dam, but its main message is to be the paradigm of the incidence of the maritime/littoral weather and its temporal sea-level rise on the coastal plains inland floods. The Santa Irene flood was attributable to a meteorological phenomenon known as gota fría (cold drop), a relatively frequent and intense rainy phenomenon on the Iberian Peninsula, particularly on the Spanish E to SE inlands and coasts. There are some circumstances that can easily come together to unleash the cold drop there: cold and dry polar air masses coming onto the whole Iberian Peninsula and the north of Africa, high sea-water temperatures, and low atmospheric pressure (cyclone) areas in the western Mediterranean basin; these circumstances are quite common during the autumn and, as it happens, in other places around the world (E/SE Africa). Their occurrence, however, shows a great space-temporal variability (in a similar way to hurricanes on Caribbean and western North Atlantic areas or also in a similar way to typhoons). In fact, all of these are equivalent, although different, phenomena, able to have a different magnitude each time. This paper describes the results of a detailed analysis and reflection about this cold drop phenomenon as a whole, on the generation of its rains, and on the different natures and consequences of its flood. This paper also explains the ways in which the nearby maritime weather and the consequential sea level govern floods on different zones of any hydrographical basin. The Santa Irene case can be considered as a paradigm to explain the influence of nearby maritime climatic conditions on flooding phenomena not only in coastal but also in upward inland areas.

Diagnosing Causes of Water Scarcity in Complex Water Resources Systems and Identifying Risk Management Actions

From the water management perspective, water scarcity is an unacceptable risk of facing water shortages to serve water demands in the near future. Water scarcity may be temporary and related to drought conditions or other accidental situation, or may be permanent and due to deeper causes such as excessive demand growth, lack of infrastructure for water storage or transport, or constraints in water management. Diagnosing the causes of water scarcity in complex water resources systems is a precondition to adopt effective drought risk management actions. In this paper we present four indices which have been developed to evaluate water scarcity. We propose a methodology for interpretation of index values that can lead to conclusions about the reliability and vulnerability of systems to water scarcity, as well as to diagnose their possible causes and to propose solutions. The described methodology was applied to the Ebro river basin, identifying existing and expected problems and possible solutions. System diagnostics, based exclusively on the analysis of index values, were compared with the known reality as perceived by system managers, validating the conclusions in all cases

A simple genetic algorithm for calibration of stochastic rock discontinuity networks

Este artículo propone un método para llevar a cabo la calibración de las familias de discontinuidades en macizos rocosos. We present a novel approach for calibration of stochastic discontinuity network parameters based on genetic algorithms (GAs). To validate the approach, examples of application of the method to cases with known parameters of the original Poisson discontinuity network are presented. Parameters of the model are encoded as chromosomes using a binary representation, and such chromosomes evolve as successive generations of a randomly generated initial population, subjected to GA operations of selection, crossover and mutation. Such back-calculated parameters are employed to make assessments about the inference capabilities of the model using different objective functions with different probabilities of crossover and mutation. Results show that the predictive capabilities of GAs significantly depend on the type of objective function considered; and they also show that the calibration capabilities of the genetic algorithm can be acceptable for practical engineering applications, since in most cases they can be expected to provide parameter estimates with relatively small errors for those parameters of the network (such as intensity and mean size of discontinuities) that have the strongest influence on many engineering applications.

Reordenación del frente costero de la Bahía de Alcudia para recuperación de embarcaciones deportivas

El objeto del presente proyecto es el diseño y definición de las obras necesarias para la construcción de una instalación de varadero para la reparación y servicio a las embarcaciones deportivas en el Puerto de Alcudia.

Presa en el río Ésera

El objeto del presente proyecto es la realización de las obras necesarias para garantizar, con alta probabilidad, el agua que necesita la zona regable del Canal de Aragón y Cataluña, lo cual permitirá el desarrollo de cultivos de mayor rendimiento económico, que mejorarán el nivel de vida de la población asentada en la zona. la Presa del Esera es una obra necesaria para avanzar en la consecución del mínimo imprescindible de 8.000 m3/ ha y año ayudando al embalse de Joaquín Costa a la atención de los riegos del Canal de Aragón y Cataluña, y como beneficios adicionales, se pueden citar: la descarga del embalse de Santa Ana y la posibilidad de un interesante aprovechamiento hidroeléctrico.

Presa de La Marmota sobre el río Manzanares

El objetivo de este proyecto es satisfacer la demanda de abastecimiento de agua de las nuevas urbanizaciones de Colmenar Viejo y del futuro parque tecnológico de Tres Cantos, ya que ésta se va a ver aumentada por la creación de nuevos planes parciales que se están desarrollando en los términos municipales de Colmenar Viejo y Tres Cantos. A parte del abastecimiento, se persiguen otros objetivos de carácter secundario, pero muy importantes que son: •Proporcionar el agua necesaria para que en épocas de estiaje no exista ningún problema de sequía en la zona. •Mantener y potenciar la calidad medioambiental de la zona por lo que en todo momento se cuidarán los aspectos medioambientales, intentando siempre minimizar la repercusión de la obra en el entorno. •Creación de empleo en la zona durante la construcción y la explotación de la presa. Además del trabajo generado por las industrias usadas para la ejecución de la obra como la central de hormigonado, la extracción en canteras, la central de áridos... •Permitir el crecimiento urbanístico proporcionando el agua necesaria

Modelling of chloride transport in non-saturated concrete : from microscale to macroscale

Corrosion of steel bars embedded in concrete has a great influence on structural performance and durability of reinforced concrete. Chloride penetration is considered to be a primary cause of concrete deterioration in a vast majority of structures. Therefore, modelling of chloride penetration into concrete has become an area of great interest. The present work focuses on modelling of chloride transport in concrete. The differential macroscopic equations which govern the problem were derived from the equations at the microscopic scale by comparing the porous network with a single equivalent pore whose properties are the same as the average properties of the real porous network. The resulting transport model, which accounts for diffusion, migration, advection, chloride binding and chloride precipitation, consists of three coupled differential equations. The first equation models the transport of chloride ions, while the other two model the flow of the pore water and the heat transfer. In order to calibrate the model, the material parameters to determine experimentally were identified. The differential equations were solved by means of the finite element method. The classical Galerkin method was employed for the pore solution flow and the heat transfer equations, while the streamline upwind Petrov Galerkin method was adopted for the transport equation in order to avoid spatial instabilities for advection dominated problems. The finite element codes are implemented in Matlab® . To retrieve a good understanding of the influence of each variable and parameter, a detailed sensitivity analysis of the model was carried out. In order to determine the diffusive and hygroscopic properties of the studied concretes, as well as their chloride binding capacity, an experimental analysis was performed. The model was successfully compared with experimental data obtained from an offshore oil platform located in Brazil. Moreover, apart from the main objectives, numerous results were obtained throughout this work. For instance, several diffusion coefficients and the relation between them are discussed. It is shown how the electric field set up between the ionic species depends on the gradient of the species’ concentrations. Furthermore, the capillary hysteresis effects are illustrated by a proposed model, which leads to the determination of several microstructure properties, such as the pore size distribution and the tortuosity-connectivity of the porous network. El fenómeno de corrosión del acero de refuerzo embebido en el hormigón ha tenido gran influencia en estructuras de hormigón armado, tanto en su funcionalidad estructural como en aspectos de durabilidad. La penetración de cloruros en el interior del hormigón esta considerada como el factor principal en el deterioro de la gran mayoría de estructuras. Por lo tanto, la modelización numérica de dicho fenómeno ha generado gran interés. El presente trabajo de investigación se centra en la modelización del transporte de cloruros en el interior del hormigón. Las ecuaciones diferenciales que gobiernan los fenómenos a nivel macroscópico se deducen de ecuaciones planteadas a nivel microscópico. Esto se obtiene comparando la red porosa con un poro equivalente, el cual mantiene las mismas propiedades de la red porosa real. El modelo está constituido por tres ecuaciones diferenciales acopladas que consideran el transporte de cloruros, el flujo de la solución de poro y la transferencia de calor. Con estas ecuaciones se tienen en cuenta los fenómenos de difusión, migración, advección, combinación y precipitación de cloruros. El análisis llevado a cabo en este trabajo ha definido los parámetros necesarios para calibrar el modelo. De acuerdo con ellas, se seleccionaron los ensayos experimentales a realizar. Las ecuaciones diferenciales se resolvieron mediante el método de elementos finitos. El método clásico de Galerkin se empleó para solucionar las ecuaciones de flujo de la solución de poro y de la transferencia de calor, mientras que el método streamline upwind Petrov-Galerkin se utilizó para resolver la ecuación de transporte de cloruros con la finalidad de evitar inestabilidades espaciales en problemas con advección dominante. El código de elementos finitos está implementado en Matlab® . Con el objetivo de facilitar la comprensión del grado de influencia de cada variable y parámetro, se realizó un análisis de sensibilidad detallado del modelo. Se llevó a cabo una campaña experimental sobre los hormigones estudiados, con el objeto de obtener sus propiedades difusivas, químicas e higroscópicas. El modelo se contrastó con datos experimentales obtenidos en una plataforma petrolera localizada en Brasil. Las simulaciones numéricas corroboraron los datos experimentales. Además, durante el desarrollo de la investigación se obtuvieron resultados paralelos a los planteados inicialmente. Por ejemplo, el análisis de diferentes coeficientes de difusión y la relación entre ellos. Así como también se observó que el campo eléctrico establecido entre las especies iónicas disueltas en la solución de poro depende del gradiente de concentración de las mismas. Los efectos de histéresis capilar son expresados por el modelo propuesto, el cual conduce a la determinación de una serie de propiedades microscópicas, tales como la distribución del tamaño de poro, además de la tortuosidad y conectividad de la red porosa.

Aparcamiento subterráneo en el Hospital Clínico San Carlos de Madrid

El presente documento tiene por objetivo la explicacion y justificacion de todos aquellos elementos que conforman el proyecto de construccion del Aparcamiento subterraneo en el Hospital Clinico San Carlos. En primer lugar se ha realizado el Estudio Previo de Soluciones, en el que se han estudiado distintas alternativas posibles para la realizacion del aparcamiento subterraneo. Tras haberlas disenado, descrito, y contrastado, se escogio la que conllevaba el mejor compendio de virtudes segun los parametros o conceptos establecidos. Una vez escogida la solucion, en la fase de estudios que nos ocupa, se procedio a redactar el proyecto de construccion propiamente dicho. Esto implica desarrollar la solucion a fondo, definiendo todos sus elementos. Para ello, se preciso de unos estudios con gran nivel de detalle que sirvieron de base para los el diseno, los calculos, y el desarrollo tecnico que ello conlleva.