Analysis of the correlation between deformation and temperature in a concrete dam

Deformational control of structures has its greatest exponent in large dams monitoring, which, depending on their structural typology, can be subjected to movements generally based on both the pressure that they upport and the temperature.The designer usually calculates the theoretical displacements that the dam will suffer onsidering the hydrostatic thrust and the temperature, but it is also true that these displacements are theoretical and they do not often fit to the real movements, due to the uncertainties that arise during the onstruction of any dam and make the final structure have changes which can be more or less significant with respect to the originally projected one. However, it is worth mentioning that they are usually lower than those theoretically calculated. The present research work focuses on a potential correlation and the subsequent determination of an mpirical model that allows calculating the deformation by means of a polynomial fit, working on the basis of temperature observations held over 14 years. This empirical model is contrasted and validated with the observations taken during the following year, and although it is only valid for the dam where the test has been made (“La Cohilla” Dam), the methodology is suitable for any other structure

Determination of an empirical model for calculating the strain of a dam in terms of hydrostatic thrust

The deformational control of structures has its greatest exponent in the control of large dams, which depending on structural typology, can be subjected to movement generally based on the pressure that it suffers. The designer usually calculates the theoretical displacements that the dam must suffer depending on the ydrostatic pressure, function of the thrust bearing, but it is also true that this calculation is theoretical and it is not usually adjusted to the real movements, due to the uncertainties that arise in the construction of any dam and make the original project have more or less significant changes in the final construction. In favour of the builder, it must be said that the actual displacements are usually lower than the theoretical ones. The present research focuses on the determination of an empirical model that allows calculating the deformation based on practical observations of a direct pendulum over 14 years, which determines the isplacement and the pressure experienced by the dam represented by the height of water contained, by means of a polynomial adjustment. This empirical model is tested and then validated with observations over the ollowing year and, although it is only valid for the dam where the trial (La Cohilla Dam) is made, the ethodology is applicable to any other structure

Economic Valuation of Cultural Heritage: Application of Travel Cost Method to the National Museum and Research Center of Altamira

The economic assessment of non-marketed resources (i.e., cultural heritage) can be developed with stated or revealed preference methods. Travel cost method (TCM) is based on the demand theory and assumes that the demand for a recreational site is inversely related to the travel costs that a certain visitor must face to enjoy it. Its application requires data about the tourist?s origin. This work aims to analyze the economic value of the National Museum and Research Center of Altamira, which was created to research, conserve, and broadcast the Cave of Altamira (UNESCO World Heritage Site since 1985). It includes an accurate replica known as the ?Neocave?. Two different TCM approaches have been applied to obtain the demand curve of the museum, which is a powerful tool that helps to assess past and future investments. It has also provided the annual economic value estimate of the National Museum and Research Center of Altamira, which varies between 4.75 and 8.00 million € per ye

Laser Scanner 3D Modeling of El Soplao Complex for Tourism Purposes (Cantabria, Spain)

La solución de un gran número de problemas prácticos, que existen en muchas áreas de la actividad humana, pasa por realizar medidas topográficas que permiten crear modelos del mundo real, a partir de los cuales es posible conseguir un cierto conocimiento sobre los objetos que son medidos y plantear la mejor solución posible para el problema suscitado. Para realizar las medidas es importante adquirir la información de forma rápida, precisa y con costes mínimos, lo que justifica la búsqueda constante de nuevas técnicas, que permitan la medida directa y continua de forma tridimensional. Así, en los últimos años de la década de los 90, se empezó a desarrollar una técnica denominada exploración con láser escáner terrestre. La aparición de estas tecnologías altera sustancialmente los métodos de trabajo y, por tanto, los resultados, siendo éstos notablemente más satisfactorios. El láser escáner modifica la concepción de levantamiento tridimensional, al obtener mediante barrido láser miles de puntos en un corto espacio de tiempo con excelentes precisiones. En base a un escaneado tridimensional de los objetos existentes en el terreno, los productos derivados de la toma de datos son múltiples, mostrando precisiones en la posición relativa de los puntos de entre 5 y 10 milímetros, a una distancia menor de 100 metros, dependiendo de la densidad de escaneado y distancia al objeto. La aplicación de esta nueva tecnología se presenta como la mejor alternativa para cubrir las expectativas de rapidez y comodidad en la captura de observables que permitan el desarrollo de bases de datos, realmente fieles, y que posibiliten conservar en formato digital la información suficiente para el mantenimiento e incluso la reconstrucción del objeto tomado. En el presente artículo se describen los trabajos realizados en este sentido en el complejo minero en el que se ubica la Cueva El Soplao (Cantabria- España), con vista a su utilización para la actividad turística

Metric contrast of thermal 3D models of large industrial facilities obtained by means of low-cost infrared sensors in UAV platforms

Monitoring for maintenance or studies of energy efficiency in buildings, large infrastructure, industrial facilities, etc., are common nowadays. These kind of studies are developed with inspections which determine the state of the facilities that are analysed. The difficulty is increased along with the size and complexity of the facility itself, and even more when the attribute to be surveyed is not noticeable or responsive for the human eye. In recent years, a series of techniques that rely on different sensors mounted on UAVs allow detecting problems that are associated with facilities of large dimensions. Almost all of them work in the visible band (RGB), but the generation of thermal 3D models permits detecting any heat anomaly related to the functioning of these facilities. This research proposes a methodology and workflow for the generation and Metric Contrast of Thermal Models (MCTM). This methodology is metrically applied to a mining-industrial facility in which thermal conditions have great influence for a proper functioning. For this metric contrast, several distances have been measured in the field and compared to those obtained from the models. The average difference between the true magnitude and those obtained from the RGB and thermal models are 5 and 31 cm, and their standard deviations are 7 and 29 cm, respectively. The comparison between the RGB and the thermal model provides an average distance between points is 0.19 m, and for 75% of the points the distance is lesser than 0.35 m. Although the RGB model is more accurate, the precision of the thermal model is enough for the objectives se

Influence of vertical movement in bathymetries and its influence on the measurement conditions

Bathymetries constitute a fundamental element of building objects settled on land submerged land: dikes, docks, underwater pipelines; in addition to dredges, volume of reservoir, etc. In civil engineering the bathymetry affect areas of small extent in which measures should be the most accurate as possible, influencing many factors in its precision. Among these factors can be distinguished: speed of sound in water, positioning system, vessel movements (pitch and roll) and vertical movement of the boat. Vertical movement of the vessel is perhaps one of the least studied factors, but their influence on the accuracy of bathymetries could be very important depending on swell conditions and depth that exists at the time of measurement. This paper defines a mathematical model based on measurements of bathymetry observed with GPS that lets you define wave conditions that found the boat according to its trajectory and speed. From this point, the article quantifies the effect of the vertical movement of the boat to correct its effect on the measured depths with an echo-sounder. Finally, from the results it is possible to obtain a set of recommendations about operations to measure a bathymetry depending on the accuracy that you should obtain

Determination of an empirical model for the deformation of a dam on the basis of the hydrostatic thrust and temperature

The deformational control of structures has its main exponent in the geometric control of large dams. Considering the constructive typology, they can suffer deformation, which is function of the hydrostatic thrust and the temperature that supports the dam under usual circumstances. The project designer usually calculates the deformation that the dam will suffer on the basis of thrust and temperature, but this calculation is theoretical, and it must be contrasted with the real data about deformation that are periodically observed in the dam, in order to certificate the adequate evolution of the structure through time. This research work is focused on the determination of an empirical model that allows the calculation of the deformation on the basis of the simultaneous observations of a direct pendulum that have been recorded with the correspondent temperatures during 14 years. This empirical model is later contrasted and validated with the records taken during the subsequent year. Although it is only valid for the dam where the tests were held (La Cohilla Dam, Cantabria, Spain), the methodology is suitable for any other structure. The main contribution of this research is the methodology itself, which allows obtaining an empirical model that determines the expected deformation, whatever the conditions of hydrostatic thrust and temperature are. It complements the theoretical model that the project designer has established, which is done just for a certain set of conditions of these variables

Optimization of Photogrammetric Flights with UAVs for the Metric Virtualization of Archaeological Sites. Application to Juliobriga (Cantabria, Spain)

ABSTRACT: Three-dimensional models are required to virtualize heritage sites. In recent years, different techniques that ease their generation have been consolidated, such as photogrammetry with Unmanned Aerial Vehicles (UAVs). Nonmetric cameras allow relatively inexpensive data collections. Traditional aerial photogrammetry has established methodologies, but there are not commonly used recommendations for the selection of parameters when working with UAV platforms. This research applies the Taguchi Design of Experiments Method, with four parameters (height of flight, forward and lateral overlaps, and inclination angle of the sensor) and three levels (L9 matrix and nine flights), to determine the set that offers the best metric goodness and, therefore, the most faithful model. The Roman civitas of Juliobriga (Cantabria, North of Spain) was selected for this experiment. The optimal flight results of the average signal-to-noise ratio analysis were height of 15 m, forward and lateral overlaps of 80%, and inclination of 0° (nadiral). This research also highlights the noticeable contribution of the inclination in the accuracy of the model with respect to the others, which is 16.4 times higher than that of the less relevant one (height of flight). This leads to propose avoiding inclination angle as a variable, and the sole development of nadiral flights to obtain accurate models

Bathymetries, history of an evolution in precision and performance

Bathymetries are a fundamental element in civil engineering when the work to be made must be based on the study of submerged terrain. In this sense, they are necessary in many situations: marine constructions such as dikes, docks, etc; dredging volume control, river flood study, etc. Traditionally bathymetries have been a difficult and costly job both in time and effort. However, over time and supported by the development of topographic and geodetic technologies, they have undergone an important transformation and progress in both precision and performance. In this sense, this article reviews the evolution of the different topographic techniques used over time, emphasizing the investigation and study of the accuracies and efficiencies typical of them; especially those that are used today. In this way, it can be concluded that, with the appropriate methodology, currently, bathymetries can be made with centimeter accuracy and with an efficiency that can exceed several square kilometers each day depending on the desired accuracy and the conditions of the bottom to be measured