EL LEVANTAMIENTO, LA REPRESENTACIÓN Y EL MODELADO ESTRUCTURAL DE UN PUENTE ANTICUADO

[EN] The in opera concrete bridges characterize often the landscapes crossed by old roads and railways. In particular the arch bridges represent a product of human genius and, in some cases, of his art. In the last few years, at the SmartLab laboratory of the University of Calabria, there were developed activities in the field of surveying, monitoring and representation of structures. In the framework of these activities, Geomatics techniques for the surveying of bridges are widely used since 2014. The results of the measurements are used for documentation and representation purposes, as well as for the reconstruction of the constructive procedures. The finite element modeling of the structures has been obtained to simulate their behavior in case of earthquake. This article describes the activities relating to a bridge dated back to the 50s of the twentieth century: it is an arch bridge made of reinforced concrete. The surveying is aimed to determine the exact reconstruction of the geometry, the identification of the foundation settlement as well as the Finite Element Modeling (FEM) in order to allow structural identification and reverse engineering process. The instruments and techniques used for surveying and modeling operations, along with the deviations between models and "as built" are described.[ES] Los puentes de hormigón in opera caracterizan a menudo los paisajes atravesados por los antiguos caminos y las vías férreas. En particular, los puentes de arco, representan un producto del ingenio humano y, en algunos casos, de su arte. En los últimos años, en el laboratorio SmartLab de la Universidad de Calabria, se desarrollaron actividades en el campo de la topografia, el monitoreo y la representación de estructuras. En el marco de estas actividades, las técnicas geomáticas relativas al levantamiento de puentes se utilizan ampliamente desde 2014. Se utilizan los resultados de las mediciones con fines de documentación y de representación, así como para la reconstrucción de los procedimientos constructivos. La modelización mediante elementos finitos de la estructura se ha obtenido para simular su comportamiento en caso de terremoto. El artículo describe las actividades relativas a un puente que data de los años 50 del siglo XX: es un puente en arco de hormigón armado. El levantamiento está dirigido a la reconstrucción exacta de la geometría, la identificación de asentamiento de la cimentación y el modelado de elementos finitos que permiten la identificación de estructuras y el proceso de ingeniería inversa. Se describen las herramientas y las técnicas utilizadas durante el levantamiento con escéner làser y las operaciones de modelado, junto con las desviaciones entre los modelos y el como fue construido "as built"Artese, S.; Lerma García, JL.; Zagari, G.; Zinno, R. (2016). THE SURVEY, THE REPRESENTATION AND THE STRUCTURAL MODELING OF A DATED BRIDGE. En 8th International congress on archaeology, computer graphics, cultural heritage and innovation. Editorial Universitat Politècnica de València. 162-168. https://doi.org/10.4995/arqueologica8.2016.3559OCS16216

Experimental and Numerical Study of Free-Surface Flows in a Corrugated Pipe

A new discharge computational model is proposed on the basis of the integration of the velocity profile across the flow cross-section in an internally corrugated pipe flowing partially full. The model takes into account the velocity profiles in the pressurised pipe to predict the flow rate under free-surface flow conditions. The model was evaluated through new laboratory experiments as well as a literature datasets. The results show that flow depth and pipe slope may affect the model accuracy; nevertheless, a prediction error smaller than 20% is expected from the model. Experimental results reveal the influence of the pipe slope and flow depth on the friction factor and the stage-discharge curves: the friction factor may increase with pipe slope, while it reduces as flow depth increases. Hence, a notable change of pipe slope may lead to the variation of the stage-discharge curve. A part of this study deals with numerical simulation of the velocity profiles and the stage-discharge curves. Using the Reynolds-Averaged Navier-Stokes (RANS) equations, numerical solutions were obtained to simulate four experimental tests, obtaining enough accurate results as to velocity profiles and water depths. The results of the simulated flow velocity were used to estimate the flow discharge, confirming the potential of numerical techniques for the prediction of stage-discharge curves

Research of the Critical Capitalization Rate in Building Damage Appraisal

From the perspective of building health monitoring and property management, this research proposes some parametric measures of the capitalization rate, in order to define a range of significant values to be used in a cash flow analysis intended for monetary evaluation in partial building damage assessment. If criteria and methods for appraising partial damage to buildings are widely shared in the scientific and professional communities, the identification of the most appropriate capitalization rate is rather more controversial, and certainly more complex. The proposed approach borrows the logical principles of cash flow analysis based on the yield capitalization approach, considering both recovery costs and loss of incomes when building partial damage occurs. The procedure is a differential valuation that considers a situation before and a situation after the damage, basing on the cost approach and the income approach. In particular, two distinct conditions are considered: the case of recovery interventions and that of improvement

Innovative Methods and Materials in Structural Health Monitoring of Civil Infrastructures

Starting from the early years of the 21st century, the problem of monitoring the physical–chemical–mechanical conditions of structures and infrastructures for civil use began to be thought in a significantly different way than in the last century [...

Innovative Methods and Materials in Structural Health Monitoring of Civil Infrastructures

Starting from the early years of the 21st century, the problem of monitoring the physical–chemical–mechanical conditions of structures and infrastructures for civil use began to be thought in a significantly different way than in the last century [...

Monitoring a Landslide with High Accuracy by Total Station: A DTM-Based Model to Correct for the Atmospheric Effects

For the monitoring of large landslides, total stations equipped with an Electronic Distance Meter (EDM) are widely used. To obtain the atmospheric parameters, required along the line of sight of every measure, the data collected by a weather station close to the instrument are usually adopted. Even after these corrections, the results obtained in the monitoring of areas with complex topography don’t reach the accuracies theoretically attainable by the high-end instruments. The article proposes a method for removing the errors due to the influence of microclimate on the measurements obtained by a high-end EDM, in order to get the maximum accuracy obtainable from such instruments. The method is based on an atmospheric model, set up by using the climatic data and a digital terrain model (DTM) of the landslide area. The methodology has been applied to a landslide in southern Italy. Over 38,000 distances, acquired for each monitored point, were used. The results demonstrate the effectiveness of the method: the standard deviations of the distances after their correction, show a reduction, ranging from 20% to 50%, with respect to the most diffused procedures; furthermore, the obtained accuracy equals the one declared by the manufacturer of the instrument for measurements in optimal conditions

TLS for Dynamic Measurement of the Elastic Line of Bridges

The evaluation of the structural health of a bridge and the monitoring of its bearing capacity are performed by measuring different parameters. The most important ones are the displacements due to fixed or mobile loads, whose monitoring can be performed using several methods, both conventional and innovative. Terrestrial Laser Scanner (TLS) is effectively used to obtain the displacements of the decks for static loads, while for dynamic measurements, several punctual sensors are in general used. The proposed system uses a TLS, set as a line scanner and positioned under the bridge deck. The TLS acquires a vertical section of the intrados, or a line along a section to be monitored. The instantaneous deviations between the lines detected in dynamic conditions and the reference one acquired with the unloaded bridge, allow to extract the displacements and, consequently, the elastic curve. The synchronization of TLS acquisitions and load location, obtained from a Global Navigation Satellite System GNSS receiver or from a video, is an important feature of the method. Three tests were carried out on as many bridges. The first was performed during the maneuvers of a heavy truck traveling on a bridge characterized by a simply supported metal structure deck. The second concerned a prestressed concrete bridge with cantilever beams. The third concerned the pylon of a cantilever spar cable-stayed bridge during a load test. The results show high precision and confirm the usefulness of this method both for performing dynamic tests and for monitoring bridges

Monitoring of Bridges by a Laser Pointer: Dynamic Measurement of Support Rotations and Elastic Line Displacements: Methodology and First Test

Deck inclination and vertical displacements are among the most important technical parameters to evaluate the health status of a bridge and to verify its bearing capacity. Several methods, both conventional and innovative, are used for structural rotations and displacement monitoring; however, none of these allow, at the same time, precision, automation, static and dynamic monitoring without using high cost instrumentation. The proposed system uses a common laser pointer and image processing. The elastic line inclination is measured by analyzing the single frames of an HD video of the laser beam imprint projected on a flat target. For the image processing, a code was developed in Matlab® that provides instantaneous rotation and displacement of a bridge, charged by a mobile load. An important feature is the synchronization of the load positioning, obtained by a GNSS receiver or by a video. After the calibration procedures, a test was carried out during the movements of a heavy truck maneuvering on a bridge. Data acquisition synchronization allowed us to relate the position of the truck on the deck to inclination and displacements. The inclination of the elastic line at the support was obtained with a precision of 0.01 mrad. The results demonstrate the suitability of the method for dynamic load tests, and the control and monitoring of bridges

Un Gis per la conservazione e la valorizzazione della via Annia - Popilia

This paper describes a methodology for implementing a GIS for the protection of artifacts, which also have historical-artistic significance, located along the route of Via Annia, better known as the ancient Roman road of Via Popilia. The aim of the work-group's research is to contribute to the development of a methodological process, with a view to the conservation and enhancement of Cultural Heritage. On a territorial scale, layer implementation will include information on geotechnical, hydro-geological, structural, urban and historical-artistic features. At the level of the single artifact, data entry is obtained through field work information gathering concerning historical and artistic relevance, location and structural aspects, and, furthermore, to develop a monitoring card, with an indication of the state of the art and critical points to be kept under control. Investigations are also to be carried out periodically with a view to necessary interventions for purposes of safety and structural recovery. Maintenance data will also be useful for future restoration and conservation projects. The pilot project concerns the case study of Ponte Sant'Angelo, known as the "Hannibal Bridge" (a Roman bridge from the 2nd century B.C.) and located between the municipalities of Altilia and Scigliano, in the province of Cosenza. The GIS can be used as an aid for the realization of tourism/related activities (guides, itineraries, on-site training, educational workshops, sites of special scientific interest, etc.)

Survey, diagnosis and monitoring of structures and land using geomatics techniques: theoretical and experimental aspects

Scuola di Dottorato Scienza e Tecnica “Bernardino Telesio, Ciclo XXVIII,a.a. 2015-2016The Geomatics techniques for the detection and representation of the land and objects have seen an exceptional development in recent years. The applications are innumerable and range from land planning to geophysics, from mitigation of landslide risk to monitoring of artifacts, from cultural heritage to medicine. With particular regard to the structures and to the land, the technologies used can be divided into three categories: techniques based on the acquisition and processing of images, techniques based on the measurement of angles and distances, and combinations of the foregoing. After an overview of Geomatics techniques and their basic theoretical concepts, a number of aspects have been thoroughly investigated. There follows a series of applications of the techniques described. Finally two new applications for deflection measurement of bridges under dynamic load are presented.Università della Calabri