Seismic Vulnerability Analysis in 3D City Models (3DCM)

UID/SOC/04647/2013 SFRH/BPD/76893/2011Lisbon is a city with high seismic risk, having been hit in the past by strong earthquakes. That’s the reason why several seismic vulnerability studies have been made devoted to the buildings of the capital, aiming the creation of different scenarios that depend on the magnitude and source location of the earthquake. The results of these studies have been presented as maps resulting from crossing information contained in 2D layers and presented in a GIS environment. 3D City Models (3DCM) intend to associate a database of a city to a rigorous geospatial representation and close to the visible reality in an urban environment, combining geometry and semantics. As such, they may include tools that convey attribute analysis at different levels, allowing the generation of new knowledge on a phenomenon or its effects, not only at the statistical level but also in terms of visual impact on the object. In this project it is intended to extend into the third dimension a seismic vulnerability study of the buildings of Lisbon held in 2D and explore the gains of spatial analysis in 3D representations. The various parameters that contribute to assess seismic vulnerability of buildings may be analyzed individually or simultaneously. The application of this tool will be demonstrated in a pilot area of Lisbon.publishersversionpublishe

Monitorização Sísmica do Território do Parque Arqueológico do Vale do Côa (PAVC)

info:eu-repo/semantics/publishedVersio

The 1909 Benavente (Portugal) earthquake : search for the source

The Lower Tagus River Valley has been affected by severe earthquakes comprising distant events, as in 1755, and local earthquakes, as in 1344, 1531, and 1909. The 1909 earthquake was located NE of Lisbon, near Benavente, causing serious damage and many losses. Mw 6.0 has been assessed for this earthquake and a reverse faulting focal mechanism solution has been calculated. Poor epicenter location, possible directivity and site effects, low fault slip rates, and the thick Cenozoic sedimentary cover make difficult correlation with regional structures. The focal mechanism indicates an ENE reverse fault as source, though it does not match any outcropping active structure suggesting that the event could have been produced by a blind thrust beneath the Cenozoic sedimentary fill. Hidden sources, inferred from seismic reflection data, are a possible NE structure linking the Vila Franca de Xira and the Azambuja faults, or the southern extension of the later. Evidence of surface rupturing is inhibited by the thick Holocene alluvial cover and the high fluvial sedimentation rate, though a slightly depressed area was identified in the Tagus alluvial plain W of Benavente which was investigated as possible geomorphic evidence of co-seismic surface deformation. A high-resolution seismic reflection profile was acquired across a 0.5 m high scarp at this site, and two trenches were opened across the scarp for paleoseismic research. Some deformation of dubious tectonic origin was found, requiring further studies

Sesame Project - Deliverable D08-02 - WP02 H/V technique : experimental conditions - Final report on Measurement Guidelines

In the following we report the final results for WP02-Measurement Guidelines. This work was conducted under the framework of the SESAME Project (Site Effects Assessment Using Ambient Excitations, EC-RGD, Project No. EVG1-CT-2000-00026 SESAME), Task A (H/V technique), Work Package 02 (WP02 – Measurement Guidelines).European Commission – Research General Directorate Project No. EVG1-CT-2000-00026 SESAMEPublished4.1. Metodologie sismologiche per l'ingegneria sismicaope

3D City Models as a Visual Support Tool for the Analysis of Buildings Seismic Vulnerability: The Case of Lisbon

Abstract 3D city models associate a database of a city to a rigorous geospatial representation that is close to the visible reality by combining appearance, geometry, and semantics. As such, these models may include tools that convey attribute analysis, not only at the statistical level but also in terms of visual appearance of the objects, thus allowing the generation of new knowledge about a phenomenon or its effects. Lisbon is a city with a moderate level of seismic risk, and has been hit in the past by strong earthquakes. Several seismic vulnerability studies of buildings have been carried out in Lisbon. These studies generate different scenarios that consider the magnitude and source location of potential earthquakes. The results of these studies were presented as maps obtained from crossing information contained in 2D layers and presented in a GIS environment. In the present study a seismic vulnerability assessment of Lisbon’s buildings held in 2D is extended to the third dimension, which refines the resolution and the set of parameters and explores the gains of spatial analysis in 3D representations. The numerous parameters that contribute to assess seismic vulnerability of buildings may be analyzed individually or simultaneously as well as in multiple seismic scenarios. Although covering all residential buildings in Lisbon, the application of the 3D city model is demonstrated with more detail in three pilot areas