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1.
G. Matas N. Lantada J. Corominas J. A. Gili R. Ruiz-Carulla A. Prades 《Landslides》2017,14(5):1565-1578
A rockfall is a mass instability event frequently observed in road cuts, open pit mines and quarries, steep slopes and cliffs. After its detachment, the rock mass may disaggregate and break due to the impact with the ground surface, thus producing new rock fragments. The consideration of the fragmentation of the rockfall mass is critical for the calculation of the trajectories of the blocks and the impact energies and for the assessment of the potential damage and the design of protective structures. In this paper, we present RockGIS, a GIS-based tool that simulates stochastically the fragmentation of the rockfall, based on a lumped mass approach. In RockGIS, the fragmentation is triggered by the disaggregation of the detached rock mass through the pre-existing discontinuities just before the impact with the ground. An energy threshold is defined in order to determine whether the impacting blocks break or not. The distribution of the initial mass between a set of newly generated rock fragments is carried out stochastically following a power law. The trajectories of the new rock fragments are distributed within a cone. The fragmentation model has been calibrated and tested with a 10,000 m3 rockfall that took place in 2011 near Vilanova de Banat, Eastern Pyrenees, Spain. 相似文献
2.
Aguilar-Meléndez Armando Pujades Lluis G. Barbat Alex H. Monterrubio-Velasco Marisol de la Puente Josep Lantada Nieves 《Natural Hazards》2022,110(3):1649-1691
Natural Hazards - There are personal and institutional decisions that can increase the seismic resilience of the buildings in a city. However, some of these decisions are possible if we have basic... 相似文献
3.
Influence of sample and terrain unit on landslide susceptibility assessment at La Pobla de Lillet,Eastern Pyrenees,Spain 总被引:2,自引:2,他引:0
The reliability of susceptibility maps depends largely on the quality of the information used for its evaluation. This study
seeks to analyze the influence of sample size and type on the results of discriminant analysis applied to shallow landslide
susceptibility assessment. The study also assesses the role of the terrain unit in discriminant analysis. To this end, two
databases based on fieldwork (slope unit) and GIS with 15- and 45-m grid cells (grid cell-based unit), were compared in the
same zone at La Pobla de Lillet, Spanish Eastern Pyrenees. The results show that although there is no significant influence
of the type of sample, it is necessary to use at least half of the individuals of the sample in order to obtain good results
from discriminant analysis. It is the terrain unit that exerts the biggest influence on the result of susceptibility. Some
morphometric parameters related to landslides were compared in the databases. The slope unit of the fieldwork database better
reflects the land characteristics than the regular grid used by GIS. The values of the variables obtained by GIS procedures
are smooth, obtaining mean errors for the slope angle variable of 19.5 and 33.5% for the grids of 15 and 45 m, respectively,
in the study area. One-way and T tests demonstrate that the smoothness of the values exerts a decisive influence on the discriminant results. Kappa’s analysis
shows that there is no significant equivalence between some of the categorical variables used in both databases. The use of
these variables demand the application of clearly defined criteria. The cell size should match the dimensions of the phenomenon
analyzed given the unsuitability of the grid of 45 m in this study. 相似文献
4.
Seismic hazard and risk scenarios for Barcelona,Spain, using the Risk-UE vulnerability index method 总被引:4,自引:1,他引:3
N. Lantada J. Irizarry A. H. Barbat X. Goula A. Roca T. Susagna L. G. Pujades 《Bulletin of Earthquake Engineering》2010,8(2):201-229
The vulnerability index method, in its version developed in the framework of the European project Risk-UE, has been adapted
and applied in this article, to evaluate the seismic risk for the city of Barcelona (Spain) through a GIS based tool. According
to this method, which defines five damage states, the action is expressed in terms of the macroseismic intensity and the seismic
quality of the buildings by means of a vulnerability index. The probabilities of damage states are obtained considering a
binomial or beta-equivalent probability distribution. The most relevant seismic risk evaluation results obtained, for current
buildings and monuments of Barcelona, are given in the article as scenarios of expected losses. 相似文献
5.
Gili J. A. Ruiz-Carulla R. Matas G. Moya J. Prades A. Corominas J. Lantada N. Nez-Andrs M. A. Buill F. Puig C. Martnez-Bofill J. Sal Ll. Mavrouli O. 《Landslides》2022,19(5):1009-1029
Landslides - Fragmentation is a common feature of rockfall that exerts a strong control on the trajectories of the generated blocks, the impact energies, and the runout. In this paper, we present a... 相似文献
6.
Vulnerability index and capacity spectrum based methods for urban seismic risk evaluation. A comparison 总被引:3,自引:2,他引:1
This article contributes to the development and application of two latest-generation methods of seismic risk analysis in urban
areas. The first method, namely vulnerability index method (VIM), considers five non-null damage states, defines the action
in terms of macroseismic intensity and the seismic quality of the building by means of a vulnerability index. The estimated
damage degree is measured by semi-empirical functions. The second method, namely capacity spectrum based method (CSBM), considers
four no damage states, defines the seismic action in terms of response spectra and the building vulnerability by means of
its capacity spectrum. In order to apply both methods to Barcelona (Spain) and compare the results, a deterministic and a
probabilistic hazard scenario with soil effects are used. The deterministic one corresponds to a historic earthquake, while
the probabilistic seismic ground motion has a probability of exceedence of 10% in 50 years. Detailed information on the building
design has been obtained along years by collecting, arranging, improving, and completing the database of the dwellings of
the city. A Geographic Information System (GIS) has been customized allowing storing, analysing, and displaying this large
amount of spatial and tabular data of dwellings. The obtained results are highly consistent with the historical and modern
evolution of the populated area and show the validity and strength of both methods. Although Barcelona has a low to moderate
seismic hazard, its expected seismic risk is significant because of the high vulnerability of its buildings. Cities such as
Barcelona, located in a low to moderate seismic hazard region, are usually not aware of the seismic risk. The detailed risk
maps obtained offer a great opportunity to guide the decision making in the field of seismic risk prevention and mitigation
in Barcelona, and for emergency planning in the city. 相似文献
7.
Ground-shaking scenarios and urban risk evaluation of Barcelona using the Risk-UE capacity spectrum based method 总被引:1,自引:0,他引:1
J. Irizarry N. Lantada L.G. Pujades A.H. Barbat X. Goula T. Susagna A. Roca 《Bulletin of Earthquake Engineering》2011,9(2):441-466
The Capacity Spectrum Based Method developed in the framework of the European project Risk-UE has been applied to evaluate
the seismic risk for the city of Barcelona, Spain. Accordingly, four damage states are defined for the buildings, the action
is expressed in terms of spectral values and the seismic quality of the buildings, that is, their vulnerability, is evaluated
by means of capacity spectra. The probabilities of the damage states are obtained considering a lognormal probability distribution.
The most relevant seismic risk evaluation results obtained for Barcelona, Spain, are given in the article as scenarios of
expected losses. 相似文献
8.
Seismic damage evaluation in urban areas using the capacity spectrum method: Application to Barcelona 总被引:8,自引:0,他引:8
Alex H. Barbat Luis G. Pujades Nieves Lantada 《Soil Dynamics and Earthquake Engineering》2008,28(10-11):851
Conceptual aspects related to seismic vulnerability, damage and risk evaluation are discussed first, together with a short review of the most widely used possibilities for seismic evaluation of structures. The capacity spectrum method and the way of obtaining seismic damage scenarios for urban areas starting from capacity and fragility curves are then discussed. The determination of capacity curves for buildings using non-linear structural analysis tools is then explained, together with a simplified expeditious procedure allowing the development of fragility curves. The seismic risk of the buildings of Barcelona, Spain, is analyzed in the paper, based on the application of the capacity spectrum method. The seismic hazard in the area of the city is described by means of the reduced 5% damped elastic response spectrum. The information on the buildings was obtained by collecting, arranging, improving and completing a broad database of the dwellings and current buildings. The buildings existing in Barcelona are mainly of two types: unreinforced masonry structures and reinforced concrete buildings with waffled-slab floors. The ArcView software was used to create a GIS tool for managing the collected information in order to develop seismic risk scenarios. This study shows that the vulnerability of the buildings is significant in Barcelona and, therefore, in spite of the low-to-moderate seismic hazard in the region, the expected seismic risk is considerable. 相似文献
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