Minimum Design Loads for Buildings and Other Structures provides requirements for general structural design and includes means for determining dead, live, soil, flood, wind, snow, rain, atmospheric ice, and earthquake loads, as well as their combinations, which are suitable for inclusion in building codes and other documents. This Standard, a revision of ASCE/SEI 7-05, offers a complete update and reorganization of the wind load provisions, expanding them from one chapter into six. The Standard contains new ultimate event wind maps with corresponding reductions in load factors, so that the loads are not affected, and updates the seismic loads with new risk-targeted seismic maps. The snow, live, and atmospheric icing provisions are updated as well. In addition, the Standard includes a detailed Commentary with explanatory and supplementary information designed to assist building code committees and regulatory authorities. Standard ASCE/SEI 7 is an integral part of building codes in the United States. Many of the load provisions are substantially adopted by reference in the International Building Code and the NFPA 5000 Building Construction and Safety Code. Structural engineers, architects, and those engaged in preparing and administering local building codes will find this Standard an essential reference in their practice. Note: New orders are fulfilled from the second printing, which incorporates the errata to the first printing.

Minimum Design Loads for Buildings and Other Structures

https://northumbria-test.eprints-hosting.org/id/document/266251

gprMax: Open source software to simulate electromagnetic wave propagation for Ground Penetrating Radar

The GPR (Ground Penetrating Radar) conference in Hong Kong year 2016 marked the 30th anniversary of the initial meeting in Tifton, Georgia, USA on 1986. The conference has been being a bi-annual event and has been hosted by sixteen cities from four continents. Throughout these 30 years, researchers and practitioners witnessed the analog paper printout to digital era that enables very efficient collection, processing and 3D imaging of large amount of data required in GPR imaging in infrastructure. GPR has systematically progressed forward from “Locating and Testing” to “Imaging and Diagnosis” with the Holy Grail of ’Seeing the unseen’ becoming a reality. This paper reviews the latest development of the GPR’s primary infrastructure applications, namely buildings, pavements, bridges, tunnel liners, geotechnical and buried utilities. We review both the ability to assess structure as built character and the ability to indicate the state of deterioration. Finally, we outline the path to a more rigorous development in terms of standardization, accreditation, and procurement policy.

A review of Ground Penetrating Radar application in civil engineering: A 30-year journey from Locating and Testing to Imaging and Diagnosis

Non-destructive techniques as a tool for the protection of built cultural heritage

Building Information Modelling (BIM) is a new process that is spreading in the Architecture, Engineering and Construction field. It allows the creation of virtual building models, which can be linked to numerical data, texts, images, and other types of information. Building components, such as walls, floors, etc. are modelled as “smart objects”, i.e. they are defined by numerical parameters, such as dimensions, and are embedded with other kinds of information, such as building materials and properties. Stored data are accessible and modifiable by all different professionals involved in the same project. The BIM process has been developed for new buildings, and it allows to plan and manage the whole building life-cycle. BIM for built heritage has started to be researched recently, and its use is still not widespread. Indeed, built heritage is characterised by complex morphology and non-homogeneous features, which clash with BIM’s standardised procedures. Moreover, to date, BIM does not allow fully automated procedures to model heritage buildings. This review focuses on the survey and digitisation phases, which can be seen as the initial phases of application of BIM in conservation projects. It also briefly covers the modelling stage. Here we present the main methodologies developed for BIM for built heritage. Issues about digitisation are also highlighted, principally in connection with the unavailability of automated processes. During the last 10 years, research has led to promising results; for example, videogame interfaces have been used to simulate virtual 3D tours that display in a single interface the 3D model and the database containing metadata, and new software plug-ins have been developed, to easily create “smart objects”. Nevertheless, further research is needed to establish how BIM can support the practice of building conservation. There is a gap in BIM’s information holding capacities, namely the storage of cultural and historical documentation, as well as monitored and simulated data relevant for preventive conservation. Future work should focus on the development of new tools that will be able to store and share all the relevant metadata.

/pdf/bim-for-heritage-science-a-review-1qapcu68iz.pdf

BIM for heritage science: a review

Structural damage detection is an important issue in conservation. In this research, principal component analysis (PCA) has been applied to the temporal variation of modal frequencies obtained from a dynamic test of a scaled steel structure subjected to different damages and different temperatures. PCA has been applied in order to reduce, as much as possible, the number of variables involved in the problem of structural damage detection. The aim of the PCA study is to determine the minimum number of principal components necessary to explain all the modal frequency variation. Three estimators have been studied: T2 (the square of the vector norm of the projection in the principal component plan), Q (the square of the norm of the residual vector), and the variance explained. In the study, the results related to the undamaged structure needed one principal component to explain the modal frequency variation. However, the high damage configurations need five principal components to explain the modal frequency. The T2 and Q estimators have been arranged in order of increasing damage for all the performed experimental tests. The results indicate that these estimators could be useful to detect damage and to distinguish among a range of intensities of structural damage.

/pdf/estimators-for-structural-damage-detection-using-principal-lck1kcq6.pdf

Estimators for Structural Damage Detection Using Principal Component Analysis

This paper reports the use of an interferometric radar to support the detection of the main vibrating frequencies of a building damaged after the Mw 5.1, May 11th 2011, Lorca earthquake (Southeast Spain). The surveyed building, a reinforced concrete structure, was located in the San Fernando neighbourhood of the city of Lorca, where the earthquake caused severe damages. The radar survey was carried out some months after the earthquake. To assess the building capacity and fragility, a pushover analysis has been carried out. The building has been modelled by using the SAP2000 software. The goal of the study is to detect changes of the main natural frequencies of a specific building after the earthquake and, through a comparison of the building frequencies before and after the earthquake, to estimate the effect of the earthquake on the monitored building.

https://iopscience.iop.org/article/10.1088/1742-6596/1149/1/012024/pdf

Using an Interferometric radar to assess post-earthquake damage status of an urban building: a case study

Applications of GPR in the Study of Cultural HeritageExamples of the Ability of the Method in Assessing Different Features

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 maintenance and the visual inspection denotes different types of damage in different zones Previous to the rehabilitation, the structure was evaluated with Ground penetrating radar (GPR) The two main objectives of the survey were determining structural arrangement of walls, floor and roof, and to detect possible damage Visual inspection indicated that some of pathologies were sunken layers, cracks and zones affected by high water content Many of the damage could be caused by the seismic hazards in the area, and the humid climate The GPR assessment was carried out with a shielded 800 MHz centre frequency antenna, covering all the different zones of the building

GPR survey in heritage structures in Chile. The case study of the Museum of Contemporary art in Valdivia: GPR survey in the MCA (Valdivia, Chile)

Resumen En este art́ıculo se presenta una metodoloǵıa que permite obtener de forma automática la geometŕıa de muros de mamposteŕıa para proceder al cálculo estructural mediante elementos finitos considerando por separado las unidades estructurales (ladrillo o piedra) y el mortero. Esta geometŕıa se obtiene mediante un proceso de detección de bordes en fotograf́ıas digitales de los muros analizados. A modo de ejemplo se presentan dos aplicaciones de esta metodoloǵıa. Una de ellas es el análisis de un muro de mamposteŕıa regular de obra. La otra aplicación es el análisis de un muro de mamposteŕıa de piedra irregular. El cálculo computacional en ambos casos se ha basado en un conocido modelo de daño isótropo que permite simular el deterioro del muro de mamposteŕıa debido a la fisuración por tracción de las juntas.

Ramón González-Drigo

Papers

Estimators for Structural Damage Detection Using Principal Component Analysis

Using an Interferometric radar to assess post-earthquake damage status of an urban building: a case study

Applications of GPR in the Study of Cultural HeritageExamples of the Ability of the Method in Assessing Different Features

GPR survey in heritage structures in Chile. The case study of the Museum of Contemporary art in Valdivia: GPR survey in the MCA (Valdivia, Chile)

Análisis estructural de muros de mampostería asistido mediante fotografía digital para la generación de la malla