The major human activities that have transformed the Earth include agriculture and urbanization. The present study was conducted to contribute to a description of the effect on birds of urbanization and agriculture in an Indian region. Terrestrial bird assemblages were censused along a five-stage urbanisation gradient between January and April 2010-2013 near the city of Amravati, on the Deccan Plateau, Central India. Altogether, 89 species of birds were recorded, with the highest species richness in the rural areas (67 species) and lowest in the urban stage (29 species). The assemblages were significantly nested in all the five stages. Maximum cumulative species abundance (12 399 individuals over four years) was found in the urban stage, and was due to the constant presence of large groups of Rose-ringed Parakeets (Psittacula krameri). The lowest bird abundance was found in the industrial zone (4837 in total), where there was also a nearly two-fold decrease from 2010 to 2013. Thirty-six species demonstrated significant variation in their densities at least in one stage and between at least two months (p&lt;0.05). Densities of 13.9% (n=5) of those species varied significantly in two stages, that of Copsychus saularis in three stages, and of Phoenicurus ochruros, in all five stages. Urban, suburban, periurban and forest stages were characterised by relatively stable species densities (significant changes observed only for 17.2% (n=5), 17.1% (n=6), 12.9% (n=7), and 17.8% (n=16) species, respectively). The additive diversity partitioning indicated that of the overall diversity (gamma-diversity), alpha diversity (within transects located within one stage) contributed 50.1% to the total diversity, and the controbution of within-stage variability was small (2.7%). Additionally, censuses on cultivated fields were taken. In two areas under mixed cropping systems, 53 bird species were identified in the two years period between June and December, 2011 and 2012. Out of the 53 detected species, only 14 were common (recorded at ≥50% of visits). Twenty-one species were recorded at Zadgaon in crops of tur (Cajanus cajan), cotton (Gossypium arboreum) and soybean (Glycine max). Nineteen species were recorded at Bhankhed in jawar (Sorghum bicolor), cotton and mung bean (Phaseolus aureus). At Zadgaon, territorial activity was observed in four species: the House Sparrow (Passer domesticus), Jungle Babbler (Turdoides striata), Yellow-eyed Babbler (Chrysomma sinense) and Red-wattled Lapwing (Vanellus indicus). The study indicated that four bird species were found under high risk, thirteen species at medium risk and eight species at low risk due to pesticide applications in croplands. The extent of crop damage in fields of groundnut, pearl millet, peas, sorghum, and sunflower was assessed by doing actual field censuses. The sustainable solution for reducing crop damage is a need for the farmers and such techniques will help to avoid direct or indirect effects of use of lethal bird control techniques on bird species diversity. / <p>QC 20141022</p>

The emphasis on seismic design and assessment of reinforced concrete (RC) frame structure has shifted from force-based to performance-based design and assessment to accommodate strength and ductility for required performance of building. RC frame structure may suffer different levels of damage under seismic-induced ground motions, with potentials for formation of hinges in structural elements, depending on the level of stringency in design. Thus it is required to monitor the seismic behaviour and performance of buildings, which depend on the structural system, year of construction and the level of irregularities in the structural system. It is the objective of the current research project to assess seismic performance of RC frame buildings in Canada, while developing fragility curves as analytical tools for such assessment. This was done through dynamic inelastic analysis by modelling selected building structures and using PERFORM-3D as analysis software, while employing incremental dynamic analysis to generate performance data under incrementally increasing seismic intensity of selected earthquake records. The results lead to probabilistic tools to assess the performance of buildings designed following the National Building Code of Canada in different years of construction with and without irregularities. The research consists of three phases; i) regular buildings designed after 1975, ii) regular buildings designed prior to 1975, and iii) irregular buildings designed prior to 1975. The latter two phases address older buildings prior to the development of modern seismic building codes. All three phases were carried out by selecting and designing buildings in Ottawa, representing the seismic region in eastern Canada, as well as buildings in Vancouver, representing the seismic region in western Canada. Buildings had three heights (2; 5; and 10-stories) to cover a wide range of building periods encountered in practice. The resulting fragility curves indicated that the older buildings showed higher probabilities of exceeding life safety and/or collapse prevention performance levels. Newer buildings showed higher probabilities of exceeding target performance levels in western Canada than those located in the east.

The extent and effect of forest fires on ancient remains and cultural heritage in the boreal forest of Sweden is relatively unknown and scarcely researched. The aim of this study is to examine how a forest fire affects the archaeological record, partly in terms of damage degree and partly in what ways a fire can change the conditions for field surveying in a forest landscape. The purpose is also to discuss work strategies for heritage protection in a future with an increased numbers of days with risk for fire. Analysis of field reports from nine different areas affected by forest fire in Sweden, together with a minor interview study indicate how the severity of the fire can be both harmful to the remains and heritage, but also helpful with the field surveying. If a fire intensity is high, it can cause direct thermal action and frost action (weathering) but it can also induce risk of mass wasting (erosion). However, the most recurring phenomena that endangers the archaeological record by covering and concealing the remains and heritage is forestry. This can cause great damage when the reforestation takes place, as scarification is notoriously harmful to the archaeological record. At the same time, a burnt forest landscape where no trees nor ground cover is left, heightens the possibility of finding new and previously unknown remains and heritage.

Road and rail tunnels are important parts of the modern infrastructure. High strength concrete (HSC) is commonly used for tunnels and other civil engineering structures, since it allows high load carrying capacity and long service life. In general, Swedish road and rail tunnels should be designed for a service life of 120 years. However, HSC has shown to be sensitive to severe fires in the moist tunnel environment, i.e., fire spalling may occur. Extensive research shows that addition of polypropylene (PP) fibres in the fresh concrete mix significantly reduces the risk of fire spalling. The durability of a concrete structure is mainly governed by the transport properties. Further, experimental studies aimed at understanding the protective mechanism of PP fibres indicate that fluid transport increases in connection with the melting temperature of such fibres. This might reduce the durability of fire exposed concrete with addition of PP fibres. This study aims to investigate whether the use of PP fibres has any significant effect on the durability of moderate fire exposed concrete structures. The experimental study focused on transport properties related to durability and stiffness reduction of fire exposed civil engineering concrete with and without addition of PP fibres. The study consists of three parts; (i) unilateral fire exposure in accordance with the standard time-temperature curve (Std) and a slow heating curve (SH), (ii) uniformly heating of non-restrained samples to 250oC, and (iii) moderate unilateral fire exposure, 350oC, of restrained samples. Changes in material properties caused by the fire exposure were studied by means of ultrasonic pulse velocity, full field-strain measurements during uniaxial compression core tests, polarization and fluorescence microscopy (PFM), water absorption and non-steady state chloride migration. The study shows that fire exposure influences different properties of importance for load carrying capacity and durability. To get a clear image of the fire damage one has to combine different test methods during damage assessments. Transport properties of concrete both with and without addition of PP fibres were considerably affected even at moderate fire exposure. Hence, the service life might be reduced. All series with addition of PP fibres exhibited higher water absorption compared to the series without PP fibres. The practical importance of this might, however, be small since also the water absorption of concrete without PP fibres was considerably affected for the fire scenarios considered in this study. Behind the fire exposed surface, i.e., between 30 and 60 mm, no change in water absorption was observed for concrete without PP fibres. However, higher water absorption of the series with addition of PP fibres was observed. Indicative fire tests aimed to evaluate the resistance to fire spalling during a subsequent severe fire was also conducted. The concretes with addition of PP fibres showed no signs of fire spalling, while progressive spalling was observed for the concrete without PP fibres. / <p>QC 20150603</p>

Freshwater mussels are particularly susceptible to injury from exposure to hazardous substances due to their sessile nature and filter feeding biology. There have been various Natural Resource Damage Assessment and Restoration (NRDAR) cases in the United States involving injury to freshwater mussels due to releases of hazardous substances into rivers and streams. Restoration of mussels in these cases typically involves propagation of mussels at a hatchery facility and their subsequent stocking or release at restoration sites. However, determination of the services lost due to injury to mussel populations and the appropriate level of restoration (and associated costs) to recover those losses has varied among NRDAR cases. Standardized methods would facilitate injury determination and restoration planning for future cases involving injury to mussels. The purpose of this research was to use two of the earliest and largest NRDAR cases (Certus, Inc. and Lone Mountain Processing, Inc. (LMPI)) involving injury to mussels to: 1) determine whether restoration for these cases was sufficient and 2) analyze restoration efforts for application in future NRDAR cases (i.e., lessons learned and development of standardized methods). This study represents the first evaluation of mussel restoration efforts in a NRDAR context. In general, 4.8% to 6.1% of juvenile mussels that excysted from host fishes in the hatchery survived to be eventually released at restoration sites. Further, based on expected survival and recruitment rates of released mussels, monitoring of restoration sites found 43% to 15% of the expected number of mussels. Understanding reasons for this discrepancy between expected and estimated survival is critical for determining the level of restoration success. If released mussels are either establishing and/or recruiting outside of monitoring area but otherwise alive and breeding, then they should count towards successful restoration. In contrast, if released mussels have either high mortality over time or are dying shortly after release, then expected gains from these mussels should not count towards successful restoration. I developed a mussel-specific Resource Equivalency Analysis (REA) for use in future NRDAR cases that compares the loss of services, using Discounted Mussel Years (DMYs) as units, to the expected gain in services from restoration. Applying this analysis to the Certus and LMPI NRDAR cases suggests that mussel restoration was successful (i.e., expected DMYs gained are greater than those lost), even when it was assumed that 75% of released mussels were dying after being released at restoration sites. Finally, a cost analysis of two mussel propagation facilities found that the yearly cost per mussel released at a restoration site ranged from $4.36 to $96.48. The suite of species propagated each year varied. As some species are more difficult to propagate than others, the cost per mussel varied widely. These data will facilitate the determination of restoration costs in future cases. Together, this information provides a starting point for consistently estimating restoration effort and costs for future NRDAR cases involving freshwater mussels. / Doctor of Philosophy / Freshwater mussels provide numerous ecosystem services. Most importantly, they purify large volumes of water, and provide habitat and food for other animals. However, they are highly vulnerable to chemical spills because they cannot move long distances quickly and they are directly exposed to toxic substances if they filter water. There have been many cases in past decades where vulnerable mussel populations were exposed to chemical spills. When these populations are injured, the services they provide are lost until the population can be restored to pre-spill conditions. Restoration of mussel populations usually involves raising juvenile mussels in hatchery facilities and then releasing them in areas where populations were injured. Determining the appropriate level of restoration needed to restore populations has varied widely among cases. A standardized approach would facilitate determination of restoration and restoration costs. I used data from two cases (Certus, Inc. and Lone Mountain Processing, Inc.) where mussel populations were injured due to a chemical spill to: 1) determine whether restoration for these two cases was successful and 2) develop tools and draw insights for use in future cases where mussels are injured. This study represents the first evaluation of restoration success of freshwater mussels in a NRDAR context. On average, 4.8% to 6.1% of juvenile mussels produced at two Virginia hatchery facilities survived to be released at restoration sites. Further, of the mussels released, only 43% to 15% of the expected mussels were found in later years. These "missing" mussels are either leaving and/or breeding outside of their release areas, or they are dying and failing to provide important ecosystem services. Further study is needed to determine the degree to which each of these is the case. I also developed a mussel-specific method of determining how much restoration is needed to provide the amount of ecosystem services as pre-spill conditions (called Resource Equivalency Analysis or REA). Application of REA to these two test cases (Certus, Inc. and Lone Mountain Processing, Inc.), I showed that restoration for these cases was successful, even if as much as 75% of released mussels are dying after being released at restoration sites. Finally, I found that the cost of successfully releasing a mussel ranged from $4.36 to $96.48 per mussel. This information is useful for estimating the cost of restoration plans in future chemical spills that injure freshwater mussels.

Approved for public release; distribution in unlimited. / An imaging radar, like ISAR, offers a combatant the capability to perform long range surveillance with high quality imagery for positive target identification. Extending this attractive feature to the battle damage assessment problem (BDA) gives the operator instant viewing of the target's behavior when it is hit. As a consequence, immediate and decisive action can be quickly taken (if required). However, the conventional Fourier processing adopted by most ISAR systems does not provide adequate time resolution to capture the target's dynamic responses during the hit. As a result, the radar image becomes distorted. To improve the time resolution, time-frequency transform (TFT) methods of ISAR imaging have been proposed. Unlike traditional Fourier-based processing, TFT's allows variable time resolution of the entire event that falls within the ISAR coherent integration period to be extracted as part of the imaging process. We have shown in this thesis that the use of linear Short Time-Frequency Transforms allows the translational response of the aircraft caused by a blast force to be clearly extracted. The TFT extracted images not only tell us how the aircraft responds to a blast effect but also provides additional information about the cause of image distortion in the traditional ISAR display.

Introdução: A avaliação do dano ou prejuízo estético na área forense tornou-se um tema de grande importância nos últimos anos, principalmente devido à atenção que a sociedade de hoje dedica à estética, a harmonia do corpo, ou à \"beleza\" do ser humano. A aparência estética tem influência nas esferas sociais, no trabalho, bem como nas relações interpessoais. Cotidianamente, um grande número de pessoas são vítimas de acidentes de trânsito e de trabalho, violência urbana, traumas pela prática desportiva, e também do erro profissional, as quais apresentam sequelas de ferimentos sediados na região maxilo-facial, e oriundos destas ocorrências. Com o aumento dessas lesões, aumentaram também a preocupação com o conteúdo dos laudos e a justa avaliação destas lesões em consequência da perda estética. Uma dificuldade para os peritos nesse tipo de avaliação são os múltiplos detalhes no exame pericial, e muito em razão da carência de padronização de protocolos e de uma metodologia adequada capaz de abordar o dano estético de maneira objetiva. Objetivo: Valendo-se de metodologia analítica específica de impressão do impacto de prejuízo estético (método AIPE adaptado transculturalmente para o Brasil - Fernandes et al, 2016) o presente trabalho voltou-se ao estudo comparativo da percepção de dano estético em quatro grupos distintos de profissionais sendo eles: Profissionais da área do Direito, médicos, cirurgiões-dentistas, e outros profissionais que não das áreas da saúde e do Direito, representando as pessoas comuns da sociedade, com intuito de verificar a homogeneidade ou não de impressões, e assim fomentar e proporcionar uma melhor aplicabilidade na Justiça. Metodologia: Os profissionais voluntários receberam presencialmente do pesquisador o método AIPE que foi aplicado numa série de casos de prejuízo estético facial simulado. Resultados: Participaram do estudo 391 pessoas, sendo elas 93 do Direito, 93 da Medicina, 107 da Odontologia e 98 de outras áreas profissionais. Os grupos mostraram diferenças de opinião, onde os grupos Direito e Medicina, próximos entre si nas valorações, exprimiram mensurações significativamente menores comparativamente aos grupos Odontologia e Outros profissionais, que também foram próximos entre si nas valorações. Os profissionais com mais de 35 anos valoraram mais que os de menos de 35 anos de idade (p<0.05). Não houve variação de opinião significante entre homens e mulheres. Conclusão: O estudo demonstrou ser possível a análise da impressão do impacto do dano estético pelo método AIPE por grupos de profissionais de diferentes formações onde foram evidenciadas as diferenças de percepção entre eles. O trabalho incorporou o tema, com intuito de unificar o entendimento de conceitos e também propiciar discussões no âmbito do Poder Judiciário e demais envolvidos, como a sociedade, pacientes e peritos na busca das melhores formas da ciência, bom senso e justiça nas avaliações do dano estético facial. O estudo demonstrou que a percepção do dano estético facial dos cirurgiões-dentistas alinha-se ao senso comum da sociedade (outros profissionais), contemplando assim a perspectiva de laudos mais condizentes, quando redigidos por estes profissionais. / Introduction: In the field of forensics, the evaluation of the aesthetic damage has become a subject of great importance in recent years. This is mainly due to the attention that the today\'s society dedicates to esthetics, the harmony of the body, or the \"beauty\" of the human being. Aesthetic appearance has an influence in social, professional, as well as interpersonal relationships. Every day, a significant number of people are victims of traffic and work-related accidents, urban violence, sports traumas, and also medical errors, which result in disfigurement and residual scarring in the maxillofacial region. With an increasing number of incidents and resulting lesions, there has a been a rising concern with the content of the reports and the whether correct evaluation of these lesions was performed regarding the consequential aesthetic loss from these lesions. Some of the difficulties for experts in this type of assessment are the quantity of details needed, combined with the lack of standardized protocols and adequate methodology capable of addressing the aesthetic damage objectively. Objective: Using the specific analytical methodology of impression of the impact of aesthetic damage (AIPE method cross-culturally adapted for Brazil - Fernandes et al., 2016) the work focuses on the comparative study of the perception of aesthetic damage in four distinct groups of professionals: law professionals, doctors, dentists, and others no Health and no Law professionals who represent a miscellaneous group in society with a view to verify the homogeneity or otherwise of impressions, and thus fostering and providing greater applicability in court. Methodology: The volunteer professionals were presented by the researcher with the AIPE method, which they applied to a series of simulated facial aesthetic damage cases. Results: In total, 391 people participated in the study; 93 in Law, 93 in Medicine, 107 in Dentistry and 98 were \"Other areas Professionals\". The groups showed differences in theirs opinion where the Law and Medicine groups were similar to each other in theirs evaluations, expressing significantly smaller measurements compared to the Dentistry group and Other professionals group, who also similar to each other. Evaluations by the professionals who were older than 35 were closer in range than those by the professionals less than 35 years of age (p <0.05). There was no significant difference in opinion between men and women. Conclusion: The study showed that it is possible to analyze the impression of the impact of aesthetic damage by the AIPE method by groups of professionals from different fields where the differences of perception between them were evidenced. The work regarding the assessment of facial aesthetic damage, was done in order to unify the understanding of concepts and also to foster discussions within the judiciary system (including society, patients, and experts) in the search of fairness, optimal use of science, and common sense. The study showed that the perception of facial aesthetic damage by dentists is aligned with the common sense of society (other professionals), thus suggesting a more appropriate perspective in reports drafted by these professionals.

Introdução: A avaliação do dano ou prejuízo estético na área forense tornou-se um tema de grande importância nos últimos anos, principalmente devido à atenção que a sociedade de hoje dedica à estética, a harmonia do corpo, ou à \"beleza\" do ser humano. A aparência estética tem influência nas esferas sociais, no trabalho, bem como nas relações interpessoais. Cotidianamente, um grande número de pessoas são vítimas de acidentes de trânsito e de trabalho, violência urbana, traumas pela prática desportiva, e também do erro profissional, as quais apresentam sequelas de ferimentos sediados na região maxilo-facial, e oriundos destas ocorrências. Com o aumento dessas lesões, aumentaram também a preocupação com o conteúdo dos laudos e a justa avaliação destas lesões em consequência da perda estética. Uma dificuldade para os peritos nesse tipo de avaliação são os múltiplos detalhes no exame pericial, e muito em razão da carência de padronização de protocolos e de uma metodologia adequada capaz de abordar o dano estético de maneira objetiva. Objetivo: Valendo-se de metodologia analítica específica de impressão do impacto de prejuízo estético (método AIPE adaptado transculturalmente para o Brasil - Fernandes et al, 2016) o presente trabalho voltou-se ao estudo comparativo da percepção de dano estético em quatro grupos distintos de profissionais sendo eles: Profissionais da área do Direito, médicos, cirurgiões-dentistas, e outros profissionais que não das áreas da saúde e do Direito, representando as pessoas comuns da sociedade, com intuito de verificar a homogeneidade ou não de impressões, e assim fomentar e proporcionar uma melhor aplicabilidade na Justiça. Metodologia: Os profissionais voluntários receberam presencialmente do pesquisador o método AIPE que foi aplicado numa série de casos de prejuízo estético facial simulado. Resultados: Participaram do estudo 391 pessoas, sendo elas 93 do Direito, 93 da Medicina, 107 da Odontologia e 98 de outras áreas profissionais. Os grupos mostraram diferenças de opinião, onde os grupos Direito e Medicina, próximos entre si nas valorações, exprimiram mensurações significativamente menores comparativamente aos grupos Odontologia e Outros profissionais, que também foram próximos entre si nas valorações. Os profissionais com mais de 35 anos valoraram mais que os de menos de 35 anos de idade (p<0.05). Não houve variação de opinião significante entre homens e mulheres. Conclusão: O estudo demonstrou ser possível a análise da impressão do impacto do dano estético pelo método AIPE por grupos de profissionais de diferentes formações onde foram evidenciadas as diferenças de percepção entre eles. O trabalho incorporou o tema, com intuito de unificar o entendimento de conceitos e também propiciar discussões no âmbito do Poder Judiciário e demais envolvidos, como a sociedade, pacientes e peritos na busca das melhores formas da ciência, bom senso e justiça nas avaliações do dano estético facial. O estudo demonstrou que a percepção do dano estético facial dos cirurgiões-dentistas alinha-se ao senso comum da sociedade (outros profissionais), contemplando assim a perspectiva de laudos mais condizentes, quando redigidos por estes profissionais. / Introduction: In the field of forensics, the evaluation of the aesthetic damage has become a subject of great importance in recent years. This is mainly due to the attention that the today\'s society dedicates to esthetics, the harmony of the body, or the \"beauty\" of the human being. Aesthetic appearance has an influence in social, professional, as well as interpersonal relationships. Every day, a significant number of people are victims of traffic and work-related accidents, urban violence, sports traumas, and also medical errors, which result in disfigurement and residual scarring in the maxillofacial region. With an increasing number of incidents and resulting lesions, there has a been a rising concern with the content of the reports and the whether correct evaluation of these lesions was performed regarding the consequential aesthetic loss from these lesions. Some of the difficulties for experts in this type of assessment are the quantity of details needed, combined with the lack of standardized protocols and adequate methodology capable of addressing the aesthetic damage objectively. Objective: Using the specific analytical methodology of impression of the impact of aesthetic damage (AIPE method cross-culturally adapted for Brazil - Fernandes et al., 2016) the work focuses on the comparative study of the perception of aesthetic damage in four distinct groups of professionals: law professionals, doctors, dentists, and others no Health and no Law professionals who represent a miscellaneous group in society with a view to verify the homogeneity or otherwise of impressions, and thus fostering and providing greater applicability in court. Methodology: The volunteer professionals were presented by the researcher with the AIPE method, which they applied to a series of simulated facial aesthetic damage cases. Results: In total, 391 people participated in the study; 93 in Law, 93 in Medicine, 107 in Dentistry and 98 were \"Other areas Professionals\". The groups showed differences in theirs opinion where the Law and Medicine groups were similar to each other in theirs evaluations, expressing significantly smaller measurements compared to the Dentistry group and Other professionals group, who also similar to each other. Evaluations by the professionals who were older than 35 were closer in range than those by the professionals less than 35 years of age (p <0.05). There was no significant difference in opinion between men and women. Conclusion: The study showed that it is possible to analyze the impression of the impact of aesthetic damage by the AIPE method by groups of professionals from different fields where the differences of perception between them were evidenced. The work regarding the assessment of facial aesthetic damage, was done in order to unify the understanding of concepts and also to foster discussions within the judiciary system (including society, patients, and experts) in the search of fairness, optimal use of science, and common sense. The study showed that the perception of facial aesthetic damage by dentists is aligned with the common sense of society (other professionals), thus suggesting a more appropriate perspective in reports drafted by these professionals.

Tunnelling in urban areas causes short-term and long-term ground movements under existing buildings. Finite element analysis provides a useful option for assessing the likely extent of damage induced in these buildings. Although finite element analysis is suggested to be used in the later phases of the building damage assessment procedures employed in practice, only the effect of short-term ground movements is typically considered and there are no detailed guidelines on the specification and complexity of the modelling. This thesis addresses the tunnel-soil-building interaction problem and the effect of long-term consolidation, as well as demonstrating the application of 3D finite element analysis with appropriate simplifications for practical assessment purposes. Finite element models are developed to quantify the effect of shallow tunnelling on an example masonry building founded on strip footings, considering both single- and twin-tunnel scenarios in a typical London soil profile. Total stress and effective stress analyses are adopted with specific modelling procedures to focus on the short-term and long-term response respectively. The analyses use a non-linear model for the masonry, and allow slippage and gapping at the soil-footing interface. Two advanced constitutive models for the soil (the extended Mohr-Coulomb model and the modified two-surface kinematic hardening model) are implemented with customized stress update schemes. The finite element results present the interaction between the soil and the building by comparing with the greenfield ground response. The horizontal coupling between the foundation and the ground is shown to be relatively weak. The dominant deformation mode of the building varies with the tunnel configuration (i.e. single or twin tunnels) and the tunnel eccentricity. Strain localization is found around the explicitly modelled window and door openings. The long-term consolidation is sensitive to the permeability of the tunnel lining. The building response to long-term ground movements is further affected by the tunnel-tunnel interaction in the case of twin-tunnel configuration. Performing 3D analysis of a single facade and foundation provides useful damage predictions, without the need to model a complete building. The proposed result processing methods such as characteristic strain and damage bar chart are practical tools for assessment. The study highlights some limitations of the elastic beam assessment method, which is often adopted in the early phase of the damage assessment process.

Changes in load characteristics, deterioration with age, environmental influences and random actions may cause local or global damage in structures, especially in bridges, which are designed for long life spans. Continuous health monitoring of structures will enable the early identification of distress and allow appropriate retrofitting in order to avoid failure or collapse of the structures. In recent times, structural health monitoring (SHM) has attracted much attention in both research and development. Local and global methods of damage assessment using the monitored information are an integral part of SHM techniques. In the local case, the assessment of the state of a structure is done either by direct visual inspection or using experimental techniques such as acoustic emission, ultrasonic, magnetic particle inspection, radiography and eddy current. A characteristic of all these techniques is that their application requires a prior localization of the damaged zones. The limitations of the local methodologies can be overcome by using vibration-based methods, which give a global damage assessment. The vibration-based damage detection methods use measured changes in dynamic characteristics to evaluate changes in physical properties that may indicate structural damage or degradation. The basic idea is that modal parameters (notably frequencies, mode shapes, and modal damping) are functions of the physical properties of the structure (mass, damping, and stiffness). Changes in the physical properties will therefore cause changes in the modal properties. Any reduction in structural stiffness and increase in damping in the structure may indicate structural damage. This research uses the variations in vibration parameters to develop a multi-criteria method for damage assessment. It incorporates the changes in natural frequencies, modal flexibility and modal strain energy to locate damage in the main load bearing elements in bridge structures such as beams, slabs and trusses and simple bridges involving these elements. Dynamic computer simulation techniques are used to develop and apply the multi-criteria procedure under different damage scenarios. The effectiveness of the procedure is demonstrated through numerical examples. Results show that the proposed method incorporating modal flexibility and modal strain energy changes is competent in damage assessment in the structures treated herein.