Damage evaluation in constructions based on geomatic and dynamic approaches

Tesis por compendio de publicaciones[EN] It seems inevitable to confirm the steady improvement of materials and construction techniques in the field of civil engineering. The evolution from stones and bricks in masonry walls to selfcompacting concretes reinforced with steel fibers or pultruded polymers is enormous. However, it is important to remember that, similar to any living being, these construction methods are not impervious to pathological processes. Though their relevance and importance differ greatly depending on the material and the kind of pathological process, they should not be overlooked, since they will influence directly the construction’s life span. Driven by the latter, this Doctoral Thesis focuses on the development of methodologies and solutions that detect, evaluate, materialize and even foresee the pathological conditions which downgrade the bearing capacity of constructions. It endorses as well, global detection and damage assessment methodologies based on geomatics (through the use of laser-scanner and photogrammetric systems) and structure-dynamics (through the Operational Modal Analysis). In order to corroborate the applicability of the developed procedures, these have been applied in various construction types: ranging from historical buildings, vernacular architecture or buildings in an experimental phase, to “modern” constructions erected with reinforced concrete. The obtained results lead to the conclusion that the sensors that have been used, as well as the techniques and methodologies that were developed, have earned an essential role in the structural evaluation of constructions. Laser-scanner and photogrammetric systems are capable of providing “plentiful” products in terms of geometric and radiometric qualities. Nevertheless, they require complementary methods in order to mechanically materialize possible building damage (except for the results provided by strategies based on Digital Image Correlation). This need is met using structure dynamic-based techniques, specifically the Operational Modal Analysis, and the Finite Element Method. Said disciplines offer a wide range of possibilities for quantifying and detecting structural pathologies in constructions.[ES]Resulta inevitable corroborar el constante avance y perfeccionamiento en el uso de materiales y técnicas constructivas en el campo de la ingeniería civil. Desde el empleo de rocas y ladrillos en mamposterías, hasta hormigones autocompactantes reforzados con fibras de acero o polímetros extruidos. Sin embargo no ha de olvidarse, que al igual que ocurre durante el transcurso vital de cualquier ser vivo, todas estas soluciones constructivas no quedan exentas de procesos patológicos. Que si bien, adquieren importancias diferentes según el tipo de proceso y material afectado, no han de pasarse por alto, condicionando consigo la vida útil de las propias construcciones. Motivado por ello, la presente Tesis Doctoral centra sus esfuerzos en el desarrollo de metodologías y soluciones, capaces de localizar, evaluar, materializar e incluso predecir aquellas afecciones patológicas que degraden la capacidad portante de las construcciones. Abogando consigo por metodologías globales de detección y cuantificación de daños basadas en las disciplinas de la geomática (a través del empleo de sistemas láser escáner y fotogramétricos) y la dinámica de estructuras (mediante el método de Análisis Modal Operacional). Con el fin de corroborar la aplicabilidad de los procedimientos desarrollados, estos son empleados en diferentes tipos de construcciones: desde construcciones históricas y vernáculas, en fase experimental hasta construcciones “modernas” erigidas en hormigón armado. A raíz de los resultados arrojados se concluye que los sensores empleados, así como las técnicas y metodologías desarrolladas, adquieren un protagonismo esencial en el conocimiento estructural de las construcciones civiles. Por un lado, los sistemas láser escáner y fotogramétricos son capaces de suministrar productos “ricos” en cualidades geométricas y radiométricas. Sin embargo, requieren de metodologías complementarias para materializar mecánicamente (a excepción de los resultados provistos por las estrategias basadas en Correlación Digital de Imágenes) posibles afecciones patológicas. La respuesta a dicha necesidad puede ser encontrada en el empleo de las técnicas basadas en la dinámica de estructuras, más concretamente en el Análisis Modal Operacional, y el Método de los Elementos Finitos. El empleo de ambas técnicas ofrece por ende un amplio espectro de posibilidades sobre el cual cuantificar y caracterizar los daños presentes en las construccione

Integration of a wearable mobile mapping solution and advance numerical simulations for the structural analysis of historical constructions: a case of study in San Pedro church (Palencia, Spain)

This work aims at enhancing the current methodologies used for generating as-built CAD models suitable for advanced numerical simulations. To this end, this paper proposes the use of a wearable mobile mapping system that allows one to improve the digitalization stage in terms of flexibility and time required. The noise showed by the resulting point cloud, based on the simultaneous location and mapping (SLAM) solution, demands a post-processing stage that introduces the use of a parameter-free noise reduction filter. This filter improves the quality of the point cloud, allowing for the adjustment of surfaces by means of parametric and non-parametric shapes. These shapes are created by using reverse engineering procedures. The results showed during this investigation highlight a novel application of this sensor: the creation of as-built CAD models for advanced numerical simulations. The results of this investigation are complemented by a valuable contribution with respect to the use of an advanced restoration solution, by means of textile reinforced mortar. To this end, the CAD model is used as the geometrical base for several numerical simulations by means of the finite element method. All this procedure is applied in a construction with structural problems.European Commission | Ref. SOE1 / P5 / P0258Junta de Castilla y León | Ref. SA075P17Junta de Castilla y León | Ref. EDU / 1100/2017European Commission | Ref. H2020-MSCA-IF-2019, n. 679 894785; proyecto AVATA

The combination of geomatic approaches and operational modal analysis to improve calibration of finite element models: a case of study in Saint Torcato church (Guimarães, Portugal)

This paper present a set of procedures based on laser scanning, photogrammetry (Structure from Motion) and operational modal analysis in order to obtain accurate numeric models which allows identigying architectural complications that arise in historical buildings. In addition, themethod includes tools that facilitate building-damage monitoring tasks. All of these aimed to obtain robust basis for numerical analysis of the actual behavior and monitoring task. This case study seeks to validate said methodologies, using as an example the case of Saint Torcato Church, located in Guimãres, Portugal

On the use minor and non-destructive methods for the safety evaluation of an historic RC bridge: the Bôco Bridge

The authors would like to express their gratitude to Tezin Nyandak and Gonçalo Escusa for their help during the experimental campaign. The work was also financed by FEDER funds through the Competitiveness Factors Operational Programme - COMPETE and by national funds through FCT – Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007633.Currently in use, the Bôco Reinforced Concrete (RC) Bridge, built in the early of 20th century, is one of the oldest RC bridges in Portugal. Its initial structural system, erected following the Hennebique system, was retrofitted in the 1960s to support heavy traffic, increasing the section of its structural components. However, the low quality of implemented retrofitting solution has promoted the presence of pathological processes, mainly concrete spalling and steel corrosion. In this context, the present paper shows the first results obtained during the second experimental campaign carried out on the bridge. This campaign comprised the use of several minor and non-destructive methods (laser scanning, operational modal analysis, and laboratory material characterization and mechanical tests), with the aim of improving the knowledge of the bridge and create an accurate numerical simulation (by means of Finite Element Model) to evaluate the safety level of this bridge. Results derived from this campaign, show a bridge with high load capacity, verifying the Ultimate Limit State.FCT -Fundação para a Ciência e a Tecnologia(POCI-01-0145-FEDER-007633)info:eu-repo/semantics/publishedVersio

Nuevas perspectivas de las fuentes de información para la Geografía Industrial

Nuevas perspectivas de las fuentes de información para la Geografía IndustrialNuevas perspectivas de las fuentes de información parala Geografía Industria

Diachronic Reconstruction and Visualization of Lost Cultural Heritage Sites

25 p.Cultural heritage (CH) documentation is essential for the study and promotion of CH assets/sites, and provides a way of transmitting knowledge about heritage to future generations. The integration of the fourth dimension into geospatial datasets enables generating a diachronic model of CH elements, namely, a set of three-dimensional (3D) models to represent their evolution in various historical phases. The enhanced four-dimensional (4D) modeling (3D plus time) pursues a better understanding of the CH scenario, enriching historical hypotheses as well as contributing to the conservation and decision-making process. Although new geomatic techniques have reduced the amount of fieldwork, when put together, the geometric and temporal dimensions imply the interpretation of heterogeneous historical information sources and their integration. However, this situation could reach a critical point when the study elements are no longer present. The main challenge is to harmonize the different historical and archaeological data sources that are available with the current remains in order to graphically rebuild and model the lost CH assets with a high degree of reliability. Moreover, 4D web visualization is a great way to disclose the CH information and cultural identity. Additionally, it will serve as a basis to perform simulations of possible future risks or changes that can happen during planned or hypothetical restoration processes. This paper aims to examine the study case of a diachronic reconstruction by means of a mobile laser system (MLS) and reverse modeling techniques for a lost urban CH element: the citadel or Alcázar gate of Ávila. Within this aim, the final model is evaluated in terms of the consistency of the historical sources to assess its suitability considering the constructive interpretations that are required to integrate heterogenous data sources. Moreover, geometric modeling is evaluated regarding the current remains and its surroundings. Finally, a web 4D viewer is presented for its dissemination and publicity. This paper is an extended and improved version of our paper that was published in the 2018 ISPRS Technical Commission II Symposium, Riva del Garda, Italy, 3–7 June 2018.S

On the Use of Historical Flights for the Urban Growth Analysis of Cities Through Time: The Case Study of Avila (Spain)

17 p.Historical aerial images are a unique and relatively unexplored means of deriving spatio-temporal information for scenes and landscapes. Such historical imagery can be combined with photointerpretation and image-based 3D modelling techniques, providing the fourth dimension of time to 3D geometrical representations. This allows urban planners, historians, and other specialists to identify, describe, and analyse changes in scenes and landscapes. Urban growth has an important impact on the sustainable development of cities. An important step for the analysis of urban growth is the identification of different urban sectors. To this end, this paper proposes a methodology for the 4D urban growth analysis of cities through time using a free and open source software developed by the authors. This approach uses the latest advances in photogrammetry, including the so-called incremental Structure from Motion, to evaluate the urbanistic changes of a city by means of confronting two-point clouds from different eras. The objectives of this paper are twofold: (i) first, the processing of historical aerial images using modern photogrammetric techniques; (ii) second, deriving spatio-temporal information for urban cities, offering a method for researchers to identify changes over time. In order to validate this method, the urban growth of the city of Avila between 1956 and 2017 was assessed taking the historical American flight of 1956 and the digital aerial flight of 2017. The results were statistically assessed according to georeferencing quality, confirming that the approach developed can be used to support urban growth analysis through time and providing relevant data in 2D and 3DS

Non-destructive means and methods for structural diagnosis of masonry arch bridges

Within the precepts defended by the International Charter of Kraków, this paper aims at presenting a fully non-destructive multidisciplinary approach able to characterize masonry bridges at three different levels: i) geometrical level; ii) material level and; iii) structural level. To this end, this approach integrates the terrestrial laser scanner, the sonic and impact-echo methods, the ground penetrating radar and the multichannel analysis of surface waves. All these data are combined with reverse engineering procedures, allowing the creation of suitable as-built CAD models for advanced numerical simulations. Then, these numerical models are contrasted and updated through the data provided by the ambient vibration tests. To validate the methodology proposed in this paper, the Roman bridge of Avila was used as study case. This bridge shows a complex mixture of constructive techniques (masonry, cohesive material, Opus Caementicium and reinforced concrete). Thus, the numerical model was considered for performing predictive structural analysis.Junta of Castilla y León | Ref. SA075P1

Differences in maternal and neonatal cardiometabolic markers and placenta status by foetal sex. The GESTAFIT project

Aims: To explore the differences in some maternal-neonatal metabolic markers and placenta status by foetal sex. Methods: One hundred thirty-nine Caucasian pregnant women from the GESTAFIT project and their new-borns were included in the present cross-sectional study. Serum cardiometabolic markers (i.e. lipid and glycaemic profile and uric acid) were analysed at late pregnancy and at birth. In placenta, telomeres length, proportion of deleted mitochondrial-DNA and mitochondrial-DNA density, some minerals and interleukin 8, epidermal growth factor, fibroblast growth factor-2 and vascular endothelial growth factor were measured. The study was run between November 2015 and April 2018. Results: Mothers carrying a male showed higher serum triglycerides than mothers carrying a female at late pregnancy (p < .05). Serum total and low-density lipoprotein cholesterol were greater in males’ umbilical cord blood artery compared to females’ new-borns (both, p < .05). Mothers of males and male new-borns presented higher uric acid than mothers of females and female new-borns at birth (p < .05). Female’s placentas presented greater placental-newborn weight ratio, manganese content and fibroblast growth factor-2 (all, p ⩽ .05), and evidence of statistical significance in telomeres length, which were 17% longer (p = .076). Conclusion: Our findings show weak differences in some cardiometabolic and placental status markers by foetal sex. Notwithstanding, we observed a slightly more proatherogenic profile in both, mothers carrying males’ foetuses and male new-borns. We also found lower serum uric acid and better placenta status in mothers carrying a female. These findings indicate that foetal sex might need to be considered for a more personalized follow-up of pregnancies.Regional Ministry of Health, Junta de Andalucia PI-0395-2016University of GranadaJunta de AndaluciaEuropean Commission SOMM17/6107/UGRPlan Propio de Investigacion 2016, Excellence actions (Units of Excellence: Unit of Excellence in Exercise and Health