Revisión y mejora de la caracterización del grado de impermeabilidad requerido por el CTE DB-HS1 para fachadas de edificación

El Código Técnico de la Edificación aprobado en 2006, asigna por primera vez en España diferentes requisitos básicos para los cerramientos verticales de edificación, destinados a limitar el riesgo de presencia inadecuada de humedad en el interior de los edificios. La solicitación por humedad, estimada mediante diversos parámetros climáticos, permite ajustar la exigencia de estos requisitos para cada emplazamiento y fachada. Sin embargo, estos parámetros presentan actualmente posibilidades de mejora que pueden dar lugar a una asignación más adecuada del grado de impermeabilidad y con ello, de los requisitos de diseño necesarios. Este artículo revisa estos parámetros climáticos, presenta otros utilizados internacionalmente para el mismo propósito y caracteriza en el territorio español los factores que determinan la solicitación por humedad, haciendo posible mejorar la prestacionalidad de los requisitos básicos impuestos para las fachadas de los edificios. The Spanish Technical Building Code published in 2006 regulates the basic requirements of building façades to prevent the inadequate presence of atmospheric water inside Spanish buildings. The moisture exposure estimate, based on several climate parameters, allows adjusting these requirements for every location and façade. However, the parameters used by the Spanish Code can be improved, resulting in a more appropriate estimate of the required water tightness degree and thus in an improvable allocations of the necessary design conditions. This paper reviews these parameters, presenting other internationally applied, and analyses the moisture exposure in the Spanish territory, which would allow improving the subsequent performance of the basic requirements imposed to the façades

Improvement of a System for Catchment, Pretreatment and Treatment of Runoff Water Using PIV Tests and Numerical Simulation

This paper studies how to improve the efficiency of a new system for catchment, pretreatment, and treatment of runoff water (SCPT). This system is integrated into an urban sustainable gravity settler that can decrease diffusive pollution. This study provides important advantages for the ecosystem by improving new sustainable drainage to clean runoff water. In this paper, an investigation methodology known as hybrid engineering (HE) was used. HE combines experimental tests and numerical simulations, both of them conducted on a 1:4-scale prototype. In this study, numerical simulations by the finite-volume method (FVM) and experimental tests by particle image velocimetry (PIV) were compared. A strong correlation between the numerical and experimental analysis was found. Next, the efficiency of the SCPTwas optimized by design of experiments (DOE). Analysis of experimental and numerical results and their comparison are presented in this paper.The authors wish to express their gratitude to the Spanish Ministry of Economy and Competitiveness for the research project BIA2009-08272 funding

Classification and comparison of snow fences for the protection of transport infrastructures

Blowing snow or sand transport generates serious problems such as transport infrastructures buried under snow or sand in many parts of the world. Some of the most important problems that snow and sand storms can cause include drivers getting trapped on the roads, traffic being held up indefinitely, accidents occurring and populations being isolated. Snow fences provide a solution to this problem as they can hold back the snow, preventing displacement and wind-induced drifting. In this way, they reduce these problems on transport infrastructures and improve visibility, providing safer driving conditions. In this review, a classification is proposed of snow fences based on three basic types: earth, structural and living snow fences. Among the structural ones, non-porous and porous snow fences are distinguished. The different possibilities in terms of the placement of snow fences are also analyzed. Finally, different types of snow fences have been compared under design, construction and operation criteria. This review can provide initial guidelines for technicians to choose the best snow fence for blizzard conditions

Energy Dissipating Devices in Falling Rock Protection Barriers

Rockfall is a phenomenon which, when uncontrolled, may cause extensive material damage and personal injury. One of the structures used to avoid accidents caused by debris flows or rockfalls is flexible barriers. The energy dissipating devices which absorb the energy generated by rock impact and reduce the mechanical stresses in the rest of the elements of the structure are an essential part of these kinds of structures. This document proposes an overview of the performance of energy dissipating devices, as well as of the role that they fulfil in the barrier. Furthermore, a compilation and a description of the dissipating elements found in the literature are proposed. Additionally, an analysis has been performed of the aspects taken into account in the design, such as experimental (quasi-static and dynamic) tests observing the variation of the behaviour curve depending on the test speed and numerical simulations by means of several finite element software packages

A search for point sources of EeV photons

Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical Journa

Reconstruction of inclined air showers detected with the Pierre Auger Observatory

We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than $60^\circ$ detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory.Comment: 27 pages, 19 figures, accepted for publication in Journal of Cosmology and Astroparticle Physics (JCAP