Vega Perez-Gracia

• Dr.
• Professor at Polytechnic University of Catalonia

Moisture is one of the main causes of degradation of heritage buildings. Early detection of zones affected by moisture is crucial information for preservation and maintenance of those structures. Ground-penetrating radar (GPR) is an effective survey method to assess damage in civil engineering and structures. Several methodologies involving this te...

Soil site studies are crucial in the analysis of seismic hazard in populated areas. This study focusses on the use of the Ground Penetrating Radar as a non-destructive geophysical method to analysis the water content of a sedimentary basin of a local urban area in Cervantes Parks in Barcelona city. Main objective of this work is to understand furth...

Suitable road pavements assessment becomes essential to provide safe traffic movements of people and goods. Moreover, a reliable transportation network is a crucial aspect of economic growth. Road pavements are subjected to various factors that influence overall performance (e.g., traffic load, temperature, moisture, delami-nation of the pavement l...

Ground penetrating radar is a geophysical survey method widely applied to the assessment and monitoring of cultural heritage buildings. It is commonly used as a method of structural evaluation because it is non-destructive and noninvasive. This chapter describes the historical development of the method and explores the fundamentals and theory of gr...

Soil site studies are crucial in the analysis of seismic hazard in populated areas. Enhancing the analysis of local seismic behaviour studies is based on the understanding of changes in ground materials of the shallow geology. Ground Penetrating Radar (GPR) is used in this study as a non-destructive geophysical method to understand the characterisa...

Print Version of the Special Issue "Trends in GPR and Other NDTs for Transport Infrastructure Assessment"

The non-destructive testing and diagnosis of transport infrastructures is essential because of the need to protect these facilities for mobility, and for economic and social development. The effective and timely assessment of structural health conditions becomes crucial in order to assure the safety of the transportation system and time saver proto...

Ground Penetrating Radar was used in this study as a non-destructive geophysical method. The main objective of this research is focused on enhancing the local seismic soil site analysis. The study employs GPR images to determine changes in the ground that can be associated with changes on the seismic soil response. To determine the GPR capacity in...

The study of surface geology by means of Ground Penetrating Radar (GPR) can provide information about abrupt lateral changes in the terrain. The location of these changes is very useful in seismic nanozonation studies, since it allows determining a priori the sectors in which the measures should be intensified. The thesis analyses the effect of cha...

Cracks in rigid pavements are a frequent and critical problem, which needs to be assessed to avoid deterioration and provide comfort and security. Control of damage requires the evaluation of cracks width and depth. Several laboratory tests were used in order to determine the ability of Ground Penetrating Radar (GPR) in the evaluation of damage und...

Ground Penetrating Radar (GPR) is a prospecting method frequently used in monitoring asphalt pavements, especially as an optimal complement to the defection test that is commonly used for determining the structural condition of the pavements. Its application is supported by studies that demonstrate the existence of a relationship between the parame...

Road pavements are subject to a range of problems due to traffic and temperature variations producing cracks that propagate to the pavement surface. Cracks need to be assessed to avoid deterioration and provide confidence in the functioning of the road system. Cracks are usually maintained after visual inspection by filling with bitumen as a first...

Road pavements are subject to traffic and temperature variations producing cracks that propagate to the pavement surface, which reduces its life and decreases circulation comfort. Early identification of pavement cracks allows for suitable maintenance and rehabilitation decreasing life cycle cost and increasing pavement life. For the development of...

Cracks in road pavements are usual damages because of heavy and dense traffic. Cracks usually are hidden to visual inspections in the case of rigid pavements. In these cases, cracked cement concrete layers are located below the asphalt layer. Therefore, detection becomes a difficult task, being only possible in the case of major damage or even fail...

Corrosion is a significant damage in many reinforced concrete structures, mainly in coastal areas. The oxidation of embedded iron or steel elements degrades rebar, producing a porous layer not adhered to the metallic surface. This process could completely destroy rebar. In addition, the concrete around the metallic targets is also damaged, and a de...

Road pavements are subject to traffic and temperature variations producing cracks that propagate to the pavement surface, which reduces its life and decreases circulation comfort. Early identification of pavement cracks allows for suitable maintenance and rehabilitation decreasing life cycle cost and increasing pavement life. For the development of...

Deterioration of concrete structure is consequence of aging, applied loads and weathering. In this paper, several laboratory tests were presented, compared to computational models and a field test case study. The purpose of the laboratory measurements is the analysis of the results in the case of different size cracks in concrete beams, filled with...

The study of structural safety when it is covered by important paintings requires a careful analysis without affecting the paintings. Therefore, non-destructive surveys are the only feasible method to obtain data about its state. In Cueva Pintada case, the problem requires a detailed but noninvasive analysis because this cave was dug in volcanic tu...

Combined non‐destructive techniques are applied in the study of a historical building in Barcelona. Santa Maria del Mar is a magnificent Mediterranean gothic church built between 1329 and 1383. Two of the most important characteristics of this building are the slender columns and the almost flat rooftop. This structure, used to create a visual impr...

Ground-Penetrating Radar (GPR) is a non-destructive geophysical method applied in many civil engineering applications. The knowledge of the GPR antennas behavior is crucial to obtain accurate results and comprehensive data interpretations. However, the age of the antennas and the use can modify the values provided by manufacturers. Consequently, ca...

The main objective of this paper is to drive a rotary inverted pendulum by following a desired navigation instruction. This navigation is commanded by the user through a new electromagnetic device which is allowed to perturb the pendulum from its upright position. This apparatus consists of an electronic magnetic driving circuit to introduce comman...

The analysis of clutter in A-scans produced by energy randomly scattered in some specific geological structures, provides information about changes in the shallow sedimentary geology. The A-scans are composed by the coherent energy received from reflections on electromagnetic discontinuities and the incoherent waves from the scattering in small het...

In Barcelona’s plane, there are a lot of paleochannels and infilled torrents that are not well located. There are some historical data of them but imprecise old cartography that leads to significant errors in accurately positioning. GPR assessment was combined with passive seismic measurements as a part of a global project based on the construction...

Outcome of COST Action TU1208: A glossary of Ground Penetrating Radar terms in 15 languages spoken in COST Countries

This work aims at presenting the main results achieved by Working Group (WG) 2 “GPR surveying of pavements, bridges, tunnels and buildings; underground utility and void sensing” of the COST (European COoperation in Science and Technology) Action TU1208 “Civil Engineering Applications of Ground Penetrating Radar” (www.GPRadar.eu, www.cost.eu). The p...

This paper presents a case study of the Mataro port combining GPR and conductivimerter surveys. Mataro port has lots of slab drop off in the dike that was supposed to be produced by sea flow wash out fine soil particles. The combination of both methods applied at the dike and a quay has permitted to detect perfectly the location of voids and distur...

The collapse of a tunnel and the damage in a second tunnel during the construction works, forced to the assessment of the ground in the front tunnel of the second structure, in order to avoid additional problems. The first evaluation was carried out with a borehole radar, because the structure was in a populated zone of a dense city. The uncertaint...

Cultural heritage buildings are irreplaceable vestiges of the civilizations. The cathedrals are usually a wide representation of styles and constructive techniques, being clear examples of the development and history of the societies. Geophysical surveys using different non-destructive methods (electrical resistivity tomography, ground penetration...

Applications of Ground Penetrating Radar (GPR) in civil engineering context are popular and it has been widely used to characterize the media in terms of structural arrangement and pathologies. This work presents some tests carried out under laboratory conditions on a concrete slab. The aim of this study is to evaluate the moisture content in a hom...

A short history of GPR and the main applications are described in this Chapter. The basic principles of GPR are also introduced, as well as the theory and fundamentals that govern the propagation of the GPR waves. Also the interaction of the electromagnetic pulses with the materials is examined. Finally, a review of the different operating modes fo...

This chapter is a review of some of the usual geophysical survey techniques applied in the assessment of civil engineering structures and infrastructures. The different techniques are based on the measurement of determined parameters and allow delineating the distribution of particular characteristics of the subsurface media. In this way, resistivi...

The assessment of cultural heritage requires high-resolution and non-destructive methodologies. Ground penetrating radar is widely applied in the inspection of historical buildings. However, some structures with curved surfaces make the radar data acquisition process difficult and consequently the following data interpretation. This paper describes...

Santa Maria del Mar is a magnificent gothic church built between 1329 and 1383 in a neighbourhood outside the city walls, over the remains of a more ancient church. The inhabitants of this district (merchants, downloaders of the port, ship-owners artisans and craftsmen) contributed and took part in the construction of this building. Nowadays it is...

Ground penetrating radar (GPR) is frequently used in pavement assessments, mainly using the evaluation of wave travel times. However, GPR data provide further information that could be used in order to determine the inner conditions and characteristics about materials. In this paper, the possible analysis of the frequency spectrum of GPR signals is...

Seismic microzonation of urban areas is used to be determined from few soils? response measurements in each area. In consequence, results can be considered correct only in the case of possible depth-dependent soils, being the existence of lateral soil changes the cause of imprecision. Ground-penetrating radar (GPR) could be a useful tool to determi...

The work presents a case study applied to the analysis of columns in cultural heritage. The GPR assessment of columns in three different places of a Modernista set of buildings allows determining the differences in constructive solutions. The study of the church denotes that the columns are masonry structures with four metallic reinforcements along...

The work presents a methodology that combines a first GPR survey and a subsequent measurement of seismic ambient noise vibration. The GPR signal characteristics used in this analysis are two: the amplitude of the background noise in the A-scans, and the frequency content of the received signal. The background noise could be consequence of three mai...

http://www.iwagpr2015.eu/sites/default/files/IWAGPR%202015%20Final%20Program%20completo.pdf

The Museum of Contemporary Art of Valdivia is located in an area characterized by high seismic vulnerability. The building and the surrounding area were truly affected by the 1960 earthquake. The edification, built in 1855, is next to the River Valdivia, which undergoes high fluctuation in the salinity. Moreover, the structure suffers of lack of ma...

The Santa Creu and Sant Pau hospital is a monumental ensemble built in Barcelona between 1901 and 1930 on the site where six small medieval hospitals were founded in 1401. It is a complex of buildings which represent the art nouveau architecture in Barcelona. It was declared World Heritage site by the UNESCO in 1997. In the previous eight decades o...

This paper describes the application of ground penetrating radar (GPR) in the study of the shallow geology of urban environments, applying the survey in Barcelona city. The objective is to determine the existence of clusters of granular materials that could be related to paleochannles or subterranean streams. The method proposed for this study is t...

A considerable number of studies about GPR applications in building inspection can be found in the literature. New advances in software development, laboratory tests under controlled conditions and numerous cases studies are representative works in this field of knowledge. Some applications are focused on rebar detection, on concrete building asses...

Preservation and maintenance of transport infrastructure is a global concern that affects social and economic development in all countries. During the last decades, there has been a continuous increase in the use of non-destructive testing (NDT) applied to many aspects related to civil engineering field. Ground Penetrating Radar (GPR) has become an...

Coastal geology in Barcelona City is formed by Quaternary sediments overlying Tertiary strata. The Quaternary plane is crossed by paleochannels and streams, all of them under the city structures and constructions. Boreholes demonstrate differences in the grain size distribution of the materials from the different geological structures. In this work...

A large number of buildings in Barcelona city were built during the XIX Century, using wooden beams and masonry. Nowadays, these structures, some of them declared architectural heritage, suffer damages and important deterioration. Geophysical surveys by means of ground-penetrating radar could provide valuable information on the most damaged areas o...

Columns are one of the most usual supporting structures in cultural heritage buildings. This work presents the study of different columns using ground-penetrating radar (GPR) combined with seismic tomography. These columns belong to a Gothic Cathedral and to a Modernista Building. In the first case, columns are constructed with regular ashlars. GPR...

Determining the behavior of a structure estimated by means of finite elements analysis requires not only an in-depth knowledge of its geometry and dynamic properties but also an experimental validation to corroborate the adequacy of the characteristics of the structure. Most of the current structural identification techniques are based on linear me...

Columns are one of the most usual supporting structures in a large number of cultural heritage buildings. However, it is difficult to obtain accurate information about their inner structure. Non-destructive testing (NDT) methodologies are usually applied, but results depend on the complexity of the column. Non-flat external surfaces and unknown and...

Columns are one of the most usual supporting structures in cultural heritage buildings. This work presents the study of different columns using ground-penetrating radar (GPR) combined with seismic tomography. These columns belong to a Gothic Cathedral and to a Modernista Building. In the first case, columns are constructed with regular ashlars. GPR...

A Laboratory device is designed to emulate the Segway motion, modifying the Furuta pendulum experiment. To copy the person on the Segway transportation unit to the Furuta pendulum, a second pendulum is added to the main one. Using LMI theory, the control objective consists to manipulate the base of the Furuta pendulum according to the inclination o...

Microzonation is widely used in seismic risk evaluations to define the predominant period values, which are usually associated with extended areas of a few hundred meters. However, the representative values corresponding to these areas are obtained from few measurements in each area. Thereby, results are accurate only in the case of depth-dependent...

Geophysical prospecting surveys are being increasingly used in non-destructive evaluations of structures, and several methods can be applied in the evaluation of cultural heritage buildings. However, accurate studies of cultural heritage structures usually need the application of combined techniques, historic and structural knowledge also being nec...

Ground penetrating radar has been fully applied in civil engineering problems. This paper presents a case study applied to a railway line evaluation. The aim of the job was to study the stability of part of a railway line, using ground penetrating radar images. Radar data was processed in order to optimize the images, and different possible causes...

High-resolution methods are required in the non-destructive study of historical buildings, archaeological sites and cultural heritage structures in general. Ground-penetrating radar (GPR) is widely used in such studies. However, radar images of archaeological sites and cultural heritage architecture tend to be unclear and are difficult to interpret...

This article presents the characterization of a mediaeval bridge located in Fillaboa, Galicia (northern Spain). The study of this bridge involves data acquisition about the structure (geometry, visual inspection of damages, and nondestructive testing), the evaluation of the possible damage mechanisms compatible with the observed cracks and fissures...

The non-destructive study of historical buildings, archaeological sites and other Cultural Heritage structures requires high resolution methodologies and a good knowledge of the potential of the different methods. Laboratory measurements provide valuable information about the ability to detect different targets and to determine structural problems,...

Ground penetrating radar has been converted in one of the most common non-destructive geophysical surveys applied to civil engineering and the evaluation of structures. However, required resolution in these kind of studies use to be elevated. In this paper, experimental measurements under controlled lab conditions and in plain media are presented....

Barcelona is placed in a basin delimited by the Mediterranean Sea (E), the Collcerola Mountains (W) and the rivers Besos (N) and Llobregat (S). The city was built on Quaternary alluvial deposits and on the Tertiary and Palaeozoic materials of the surrounding mountains. The Quaternary materials are preponderant in the plane of the city, presenting a...

Ground-penetrating radar (GPR) is a geophysical and close-range remote sensing technique based on the use of radar pulses to obtain cross-section images of underground features. This method is characterized by the transmission of an electromagnetic short length pulse (1-2 ns), presenting a centre frequency ranging from 10 MHz to 2.5 GHz. The princi...

This paper presents a methodology developed to obtain the geometry of masonry walls. The methodology is based on the automatic recognition of boundaries. The geometry is used to perform the numerical simulation of the cracking process due to tensile stresses in joints. Masonry units are considered as linear elastic elements, and the non-elastic pro...

The aim of this study was to apply Nakamura's technique to Valencia city center, after some preliminary tests in Barcelona. Previous studies of Barcelona had measured periods in restrictive conditions and in various types of material ranging from very soft soil (with a predominant period of approximately 2 s) to rock (0.3 s), and under different me...

This paper describes an integrated near-surface geophysical study carried out in order to obtain high-resolution images of the shallow subsurface under and around the Cathedral of Mallorca. The study was a part of a global project focused on determining the state of the building structure and on evaluating the Cathedral's dynamical behaviour (natur...

High-resolution ground-penetrating radar (GPR) evaluations of structures are usually carried out using antennas with high nominal centre frequencies (between 1 and 2 GHz). A comprehensive characterization of such an antenna would make it possible to determine the capabilities of a system and obtain accurate data interpretations. This paper describe...

Historical and heritage buildings have been remodelled lots of times in his large history, especially for old private ones. For some years these historical buildings have been used for other public o private uses than the one which were designed. Especially important are the remodelling carried out during the last few decades, using extensively con...

This paper summarizes various approaches to determine the spatial resolution (SR) in non-destructive ground-penetrating radar (GPR) studies and compares the results obtained in these approaches to experimental data acquired in two different media. In one of the experimental measurements, we used 0.4 mS/m conductivity water, which is a low-attenuati...

Ground-penetrating radar (GPR) is a non-destructive geophysical technique that is used to analyse soils and structures by providing continuous images of the interior of the media being analysed. In this paper, we present the methodology and results of a study of the reinforced concrete base of a large block of flats, where flow water and flooding a...

The campus of the College of Industrial Engineering of Barcelona was recently declared an Architectural Heritage Site due to the value of its Modernista buildings, which were built in 1868 under the direction of the architect Rafael Guastavino (1842–1908). The site housed one of Europe's largest textile factories during the 19th century and was lat...

This paper describes the ground-penetrating radar (GPR) survey carried out on the Roman theatre of Sagunto (Valencia, Spain) following recent restoration work in 1991. The structure has been substantially altered a number of times: it was remodelled during the Roman and Moorish periods, partially destroyed during the Peninsular War (1808–1814) and...

Traditional architectonic heritage elements are fragile and irreplaceable resources, signs of the ancient ways of life and the history of the modern societies, and essential valuable elements of the own landscape of a region. Accurate updated documentation might be the basis for any conservation or restoration intervention over architectonic herita...

Ground-penetrating radar (GPR) is a high resolution surveying method applied to civil engineering, surface geology, archaeology and other disciplines. Mainly it is used solving the direct problem and obtaining a model of the studied medium. Otherwise, the study of the inverse problem could provide other valuable information: the electromagnetic pro...

Ground-penetrating radar (GPR) is a high resolution surveying method applied to civil engineering, surface geology, archaeology and other disciplines. Today, GPR is an effective technique for investigating the integrity of concrete structures. As a non destructive technique, it is particularly suited for the assessment of large structures such as p...

Ground-Penetrating Radar has become a popular non-destructive and non-invasive tool in different kind of applications: civil engineering, archaeology, concrete and masonry analysis, etc. The selection of the antenna frequencies depends on the application, but each antenna has a radiation pattern and some characteristics that have influence in the f...

Este proyecto tiene la finalidad de adaptar los contenidos y recursos docentes a las necesidades actuales, permitiendo así, aplicar el modelo pedagógico de enseñar a aprender. Como método en la relación enseñanza-aprendizaje, se plantea aplicar el rol del profesor como guía en el proceso de aprendizaje para lo que se prepara un material de estudio...

Dentro del proyecto de estudio de la vulnerabilidad sísmica de la Ciutat Vella de Valencia se ha estudiado la respuesta de suelo de esta y su afectación a los edificios de vivienda existentes. Debido a la baja sismicidad de la zona, las características urbanísticas y al bajo coste, la respuesta de suelo se ha calculado mediante el método del cocien...

The Ground-penetrating radar (GPR) analysis of some modernist buildings of the Technical Industrial School of Barcelona allow us to obtain valuable information of the underground constructions, corresponding to ancient structures of the preceding factory. The actual school is building on the modernist industrial complex. Many changes in the structu...

Ground penetrating radar (GPR) is a suitable method to study shallow ground anomalies based on the propagation of electromagnetic waves. The characteristics of the received signal depend on the electromagnetic properties of the materials, which depend on the type of matter of the medium and their physical properties (mainly water content and porosi...

Este estudio recoge los principales resultados del trabajo sobre modelización de la anelasticidad en la Península Ibérica a partir de ondas de Coda correspondientes a una selección de 935 registros sísmicos digitales registrados en 27 estaciones pertenecientes al Instituto Geográfico Nacional (IGN). Los sismos disponibles para este estudio ocurrier...

Ground-penetrating radar, GPR, is a remote sensing technique based on the use of radio&micro waves to obtain cross-section images of underground features using in-situ sensors. GPR principles of operation are based in the ability of low frequency radar waves to penetrate into non-conductive medium, usually subsoil but also walls, concrete or wood....

This paper describes the ground-penetrating radar (GPR) survey performed inside the Cathedral of Valencia, Spain. It is part of historical studies performed in the Cathedral in order to add information to old maps and documents in the Cathedral Archives and also to analyze the extent and importance of potentially destructive moisture areas that wer...

Local area networks (LANs) are important for an enterprise to hold a competitive edge. Many companies have therefore converted terminal-based computing systems to LAN-based distributed data processing systems. This paper proposes a design methodology for distributed databases connected by a LAN. Two primary objectives of the methodology are: (i) to...