New mechanism for continuous and bidirectional displacement of heavy structures: Design and analysis

The aim of this paper is to design and study a new mechanism for moving heavy structures using the force of friction. The mechanism designed is called DCACLM and was patented in 2011. This new device is based on an inverted crawler which is able to displace heavy structures such as large span bridges in a continuous and bidirectional way. Furthermore, the DCACLM design has taken into account other important aspects such as safety and sustainability in order to develop new construction methods. Nonlinear numerical models using the Finite Element Method have been developed to study the complex structural behavior of this new mechanism. The main conclusions provide acceptable results in terms of stresses and strains for the main elements of DCACLM.the authors wish to acknowledge the financial support provided by the Spanish Ministry of Science and Innovation with funds from ALCANZA Research Project number IPT-380000-2010-12. This project has been co-financed with FEDER funds, “A Way of Making Europe”

Improvement of a functional method to determine the design thermal transmittance of building façades. Implementation in southern Spain

The thermo-hygrometric conditions to which construction materials are subjected cause their thermal performance to vary by location. These variations must be characterised in order to design building envelopes adjusted to the requirements of each situation, thus contributing to improve their energy efficiency under actual operating conditions. To this end, a functional calculation procedure that corrects the standardised thermal conductivity values of façade materials (¿-value) has been recently proposed; which considers the climatic characteristics of each location. This work proposes and validates improvements that, while preserving its functionality, overcome some limitations of the original procedure. To calculate more accurate corrections, the façade configuration and the climatic zones established by the building codes are also considered, allowing a more reliable characterisation of the design thermal transmittance of each building façade. By using climatic records gathered from 316 weather stations, a detailed isopleth map is also developed to present the applicable corrections for more than 250, 000 km2 of southern Spain. The largest ¿-value corrections are identified on the southeast coast and reach up to +6% in the summer months (with average annual corrections above +4%). This improved procedure can be extrapolated to any national building code that establishes constant values of thermal conductivity for façade materials and that defines thermal design requirements based on climatic zones

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

Performance analysis of wind fence models when used for truck protection under crosswind through numerical modeling

This paper is focused on truck aerodynamic analysis under crosswind conditions by means of numerical modeling. The truck was located on the crest of an embankment during the study. In order to analyze the performance of three wind fence models, the truck's aerodynamic coefficients were obtained and compared in two different situations either with or without the wind fences installed. In addition, the effect of both height and porosity of wind fence models on the aerodynamic coefficients acting on truck with respect to separation distance between the truck and the wind fence, was analyzed. A finite volume (or computational fluid dynamic) code was used to carry out the numerical modeling. The Reynolds-averaged Navier?Stokes (RANS) equations along with the k?? SST turbulence model were used to predict the behavior of turbulent flow. With respect to the results, the influence of the distance on the rollover coefficient is soft for all height values studied except for the lowest value (1 m of fence height), where the maximum value of rollover coefficient was obtained for the truck position closer to the fence. Regarding fence porosity, its effect on rollover coefficient is stronger for truck positions on road closer to the wind fence model.This work was supported by the OASIS Research Project that was co-financed by CDTI (Spanish Science and Innovation Ministry) and developed with the Spanish companies: Iridium, OHL Concesiones, Abertis, Sice, Indra, Dragados, OHL, Geocisa, GMV, Asfaltos Augusta, Hidrofersa, Eipsa, PyG, CPS, AEC and Torre de Comares Arquitectos S.L. and 16 research centres. The authors would also like to thank the GICONSIME research group of the University of Oviedo (Spain) for their collaboration in this research

Ultrahigh energy neutrinos at the pierre auger observatory

The observation of ultrahigh energy neutrinos (UHEs) has become a priority in experimental astroparticle physics. UHEs can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going ) or in the Earth crust (Earth-skimming ), producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). In this work we review the procedure and criteria established to search for UHEs in the data collected with the ground array of the Pierre Auger Observatory.This includes Earth-skimming as well as downward-going neutrinos. No neutrino candidates have been found, which allows us to place competitive limits to the diffuse flux of UHEs in the EeV range and above

Description of Atmospheric Conditions at the Pierre Auger Observatory using the Global Data Assimilation System (GDAS)

Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malarg\"ue and averaged monthly models, the utility of the GDAS data is shown

Design of a new prefabricated road subsurface drainage system

Water flow through road structures is a topic of great interest in civil engineering, as water is one of the factors that most affects the hydraulic and mechanical behavior of road materials. Efficient design of subsurface drainage improves the performance of road pavement. Conventional drainage systems, such as trench drains may not be wholly effective in reducing water-related problems, and in fact, may inadvertently reduce pavement performance and service life. This can be because conventional drainage is projected in saturated conditions; however, most water flow near the surface occurs under unsaturated conditions. This paper presents an experimental study to design a new prefabricated prototype for the subsurface drainage of road pavements (SubDrain). SubDrain has been designed by using rapid prototyping Selective Laser Sintering (SLS) with powder polyamide material and experimental validation tests, with the aim to evaluate the mechanical and hydraulic behavior of the prototype. The results of this study show that the new prefabricated prototype is a potential technology solution to replace the conventional trench drain systems currently used in road projects. Findings in this study are limited to a prototype tested only under laboratory conditions