A WebGis tool for seismic hazard scenarios and risk analysis

The WebGis development represents a natural answer to the growing requests for dissemination and use of geographical information data. WebGis originates from a combination of web technology and the Geographical Information System, which is a recognised technology that is mainly composed of data handling tools for storage, recovery, management and analysis of spatial data. Here, we illustrate two examples of seismic hazard and risk analysis through the WebGis system in terms of architecture and content. The first presents ground shaking scenarios associated with the repetition of the earthquake that struck the Lake of Garda area (northern Italy) in 2004. The second shows data and results of a more extensive analysis of seismic risk in the western part of the Liguria region (north-western Italy) for residential buildings, strategic structures and historic architecture. The adoption of a freeware application (ALOVMap) assures easy exportability of the WebGis structures for projects dealing with natural hazard evaluation

Fracture behaviour of single crystal silicon microstructures

The fracture behaviour of single crystal silicon (SCSi) microstructures is analysed based on microme-chanical torsional and tensile experiments. The uniaxial testpieces are characterised by the presence of sharp not-ches at the gauge length extremities. The critical loading conditions are reproduced in a finite element model in order to identify the analogies of the failure conditions in tension and torsion. The stress field in the vicinity of the notch tip (were cracks originate) is analyzed, and fracture mechanics parameters are determined. In the finite element model a crack, reproducing the failure process observed in the experiments, is included. The crack area is incrementally increased and the energy release rate for the critical loading conditions in tension and torsion is calculated. Based on these results a failure criterion is formulated along with a procedure for the mechanical integrity analysis of SCSi microstructures of arbitrary shape and loading condition

Stima speditiva degli scenari di danno sismico atteso per edifici in muratura mediante l’utilizzo di curve di Probit

Nel presente lavoro si presentano le curve di vulnerabilità degli edifici in muratura ricavate dall’analisi dei dati del terremoto del Friuli del 1976. In particolare le curve sono ricavate tramite l’analisi di Probit, una tecnica statistica largamente in uso nel campo delle analisi di rischio industriale e più in generale nei settori in cui si studiano fenomeni governati da una legge dose-effetto di tipo sigmoidale. Nell’articolo si mostra come tali curve possono essere direttamente impiegate per valutazioni previsionali di danno atteso su scala territoriale in quanto consentono di ricavare in modo relativamente semplice e rapido la percentuale di edifici che, sottoposti ad una determinata azione sismica, subiscono un determinato livello di danno strutturale espresso nella scala EMS-98. Nel lavoro si propone inoltre una metodologia di stima più ampia dello “scenario di danno”, basata sull’uso di una matrice di correlazione che lega l’indice di danno EMS-98 agli effetti indiretti in termini di giudizio di agibilità, riparabilità e probabilità di vittime associate. Tale matrice, anch’essa messa a punto sulla base dei dati del terremoto del Friuli, è stata validata e calibrata sui dati dalle schede AeDES compilate in occasione del terremoto Umbria-Marche

A WebGIS tool for the dissemination of earthquake data

In 2004 a new seismic hazard map of Italy (MPS Working Group, 2004) has been released by a task force that produced an amount of new or updated data, such as a new version of the earthquake catalogue (CPTI04; CPTI Working Group, 2004) and an updated seismogenic zonation. A set of WebGIS tools has been designed for the data dissemination to the scientific community and the general public. The design of the WebGIS tools focused first on the consultation of the DBM04 macroseismic database (DBM Working Group, 2005), which contains the macroseismic intensity data-points (IDP) of the earthquakes listed in the CPTI04 catalogue. The WebGIS tool design and development process had to fulfill: 1) simplicity, 2) responsiveness and 3) readiness for future extensions. The specific requirements for the macroseismic database consultation interface were: - data access by place and by earthquake; - IDP maps with queryable points; - data download in both tabular and map format; - easily upgradable content; - quick and user friendly interface

Assessing seismic damage through stochastic simulation of ground shaking: the case of the 1998 Faial Earthquake (Azores Islands)

In July 1998, an Mw = 6.2 earthquake struck the islands of Faial, Pico and San Jorge (in the Azores Archipelago), registering VIII on the Modified Mercalli Intensity scale and causing major destruction in the northeastern part of Faial. The main shock was located offshore, 8 km North East of the island, and it triggered a seismic sequence that lasted for several weeks. The existing data for this earthquake include both the general tectonic environment of the region and the teleseismic information. This is accompanied by one strong-motion record obtained 15 km from the epicentre, the epicentre location of aftershocks, and a large collection of the damage inflicted to the building stock (as poor rubble masonry, of 2-3 storeys). The present study was carried out in two steps: first, with a finite-fault stochastic simulation method of ground motion at sites throughout the affected islands, for two possible locations of the rupturing fault and for a large number of combinations of rupture mechanisms (as a parametric analysis); secondly, the damage to buildings was modelled using a well-known macroseismic method that considers the building typologies and their associated vulnerabilities. The main intent was to integrate different data (geological, seismological and building features) to produce a scenario model to reproduce and justify the level of damage generated during the Faial earthquake. Finally, through validation of the results provided by these different approaches, we obtained a complete procedure for the parameters of a first model for the production of seismic damage scenarios for the Azores Islands region

Quantum Correlations in the Minimal Scenario

In the minimal scenario of quantum correlations, two parties can choose from two observables with two possible outcomes each. Probabilities are specified by four marginals and four correlations. The resulting four-dimensional convex body of correlations, denoted $\mathcal{Q}$, is fundamental for quantum information theory. It is here studied through the lens of convex algebraic geometry. We review and systematize what is known and add many details, visualizations, and complete proofs. A new result is that $\mathcal{Q}$ is isomorphic to its polar dual. The boundary of $\mathcal{Q}$ consists of three-dimensional faces isomorphic to elliptopes and sextic algebraic manifolds of exposed extreme points. These share all basic properties with the usual maximally CHSH-violating correlations. These patches are separated by cubic surfaces of non-exposed extreme points. We provide a trigonometric parametrization of all extreme points, along with their exposing Tsirelson inequalities and quantum models. All non-classical extreme points (exposed or not) are self-testing, i.e., realized by an essentially unique quantum model. Two principles, which are specific to the minimal scenario, allow a quick and complete overview: The first is the pushout transformation, the application of the sine function to each coordinate. This transforms the classical polytope exactly into the correlation body $\mathcal{Q}$, also identifying the boundary structures. The second principle, self-duality, reveals the polar dual, i.e., the set of all Tsirelson inequalities satisfied by all quantum correlations. The convex body $\mathcal{Q}$ includes the classical correlations, a cross polytope, and is contained in the no-signaling body, a 4-cube. These polytopes are dual to each other, and the linear transformation realizing this duality also identifies $\mathcal{Q}$ with its dual.Comment: We also discuss the sets of correlations achieved with fixed Hilbert space dimension, fixed state or fixed observable

Application of a prioritisation scheme for seismic intervention in schools buildings in Italy

A risk management framework has recently been developed to assign priorities for the rehabilitation of school buildings in Italy, and to give timescales within which retrofit or demolition must take place. Since it is not practical to carry out a detailed assessment of the 60,000 Italian state and public schools, the framework is a multiple-level procedure which aims to identify the highest-risk buildings based on filters of increasing detail, and reduces the size of the building inventory at each step. The first risk ranking is based on a strength deficit, which measures the difference between the current design forces defined for the building site and an estimation of the level of seismic resistance which was required at the time of design. The second ranking is based on lateral strength calculations that are already available for a large portion of the Italian masonry building stock, and that are obtained from a survey form that is familiar to Italian engineers. Finally, a simplified displacement-based methodology is used to give a more accurate assessment of seismic risk based on a limited amount of geometrical and material data. The final assessment leads to a capacity ratio and a risk rating, which are used within a transparent procedure to assign priorities for seismic intervention, and timescales within which detailed assessment leading to retrofit or demolition must take place. The first step of the methodology has been applied herein to the school building stock within two Regions in Italy and preliminary results are presented

THE 9TH JULY 1998 FAIAL EARTHQUAKE: COMPARISON OF STOCHASTIC FINITE FAULT DAMAGE SIMULATION WITH SURVEYED DATA

The Azores earthquake, July 9, 1998 (Mw 6.2) caused a large damage to the stock of old masonry buildings, with maximum felt intensity Is=VIII (MMI). A stochastic strong ground motion (SM) was simulated on the islands struck by the earthquake using published fault solution, to derive maps of average Peak Ground Acceleration (PGA) at bedrock. Detailed analysis was done at the Horta station comparing stochastic-computed and observed PGA, PGV, Response Acceleration Spectra and Response Spectrum Intensity (SI) values. Although recordings on Faial (Horta) and Terceira Islands are not enough to fully constrain the simulation parameters, they can define the range of possible variation. Relationships between PGA and MMI were used to retrieve intensity. Retrieved and observed intensities allowed to derive an average damage index according to the EMS-98 classification

La difesa dai terremoti in Lombardia: stato dell’arte e prospettive

L’INGV (http://www.mi.ingv.it/) svolge in Lombardia ricerche nel campo della mitigazione del rischio sismico, mediante studi mirati al miglioramento delle conoscenze sulla storia sismica, sul modello strutturale legato al regime tettonico in atto e alla definizione del moto del suolo atteso. Accanto alle indagini necessarie alla caratterizzazione sismogenetica e dei possibili effetti dello scuotimento sismico, si pone l’attività di monitoraggio sismico, che la Sezione di Milano-Pavia espleta mediante la rete accelerometrica (RAIS, http://rais.mi.ingv.it/) che consta di 20 postazioni distribuite in prevalenza sul territorio regionale. In un recente lavoro di sintesi - di studi pluriennali su fonti storiche e di revisioni critiche di materiali pubblicati - si è tentato di colmare l’evidente carenza conoscitiva sulle caratteristiche della sismicità storica dell’area lombarda. Tale carenza è particolarmente evidente se si rapportano le informazioni oggi disponibili sui terremoti del passato in quest’area con quelle relative al settore veneto-friulano. La regione analizzata, compresa tra il bacino del fiume Adda e il Lago di Garda, è stata caratterizzata da alcuni terremoti con Mw>5.5 (es., 1117, Veronese; 1222, Brescia; 1901, Salò) e vari eventi con Mw compresa fra 4.8 e 5.5 (es., 1065, Brescia; 1396, Monza; 1642, Bergamo). Per molti degli eventi sismici fino al 1700 le informazioni sono desumibili soltanto da scarse fonti storiche. La determinazione epicentrale e l’attribuzione della magnitudo per tali eventi sono da considerarsi, pertanto, con una certa cautela al fine di definire le caratteristiche sismiche del territorio. I terremoti del 1117 e del 1222, in tale contesto, rappresentano un’eccezione rispetto ai dati generalmente disponibili. E tuttavia vari problemi tuttora aperti rendono assai difficile l’utilizzo della distribuzione del danno attribuibile a questi eventi nella prospettiva di un’affidabile parametrizzazione. Le indagini geologico-strutturali e di geologia del Quaternario, finalizzate a definire un quadro strutturale compatibile con il regime tettonico in atto, sono necessarie per giustificare la storia sismica e, in sostanza, per definire il comportamento sismogenetico della regione. Le geometrie dei sistemi di faglia attivi alpini sono ora sufficientemente noti. Le conoscenze permettono di formulare ipotesi sismotettoniche relative all’origine dei terremoti dell’area gardesana e del Bresciano. In via di definizione sono invece le geometrie dei fronti appenninici, cui sono attribuibili i terremoti al di sopra della soglia nel settore padano. Le ricerche attuali sono altresì indirizzate ad una migliore caratterizzazione del complesso settore compreso tra la parte meridionale del Lago di Garda (area di Sirmione), Verona e Mantova, all’interno del quale potrebbe collocarsi l’area epicentrale del terremoto del 1117 (o una delle aree epicentrali, qualora si considerasse questo evento come rappresentato da una sequenza sismica). Uno dei settori regionali con maggiore frequenza di eventi sismici è l’area gardesana occidentale, per questo motivo la rete di monitoraggio presenta una notevole densità di postazioni nel Bresciano e se ne è pianificato l’addensamento nel Veronese. Nel corso del 2007, la rete ha consentito la registrazione di 516 forme d’onda relative a 28 eventi locali e regionali (di cui una decina localizzati nell’area citata) con magnitudo da 1.3 a 4.2, di cui sono stati calcolati i parametri di interesse ingegneristico. L’analisi delle registrazioni ha permesso di ricavare informazioni utili per il calcolo di scenari di scuotimento. Un esempio di taali applicazioni è rappresentato dallo scenario realizzato utilizzando come terremoto di riferimento l'evento del 24 Novembre 2004 (M 5.2)

Anti-fibroblast antibodies detected by cell-based ELISA in systemic sclerosis enhance the collagenolytic activity and matrix metalloproteinase-1 production in dermal fibroblasts

Objectives. Antibodies binding to the surface of fibroblasts (anti-fibroblast antibodies: AFA) have been described in systemic sclerosis (SSc). We aimed to assess the effect of AFA on extracellular matrix (ECM) turnover and whether AFA were associated with anti-topoisomerase-I antibody. Methods. IgG were purified from AFA-positive and AFA-negative sera selected within 20 SSc and 20 healthy individuals, and tested on normal dermal fibroblasts, at protein and mRNA level, for their capacity to induce collagen deposition or degradation. Results. Fibroblasts stimulated with AFA-positive but not with AFA-negative and control IgG showed an increased capacity to digest collagen matrix and produce metalloproteinase-1 (MMP-1) while their production of total collagen, type I collagen and tissue inhibitor of metalloproteinase-1 (TIMP-1) was unaffected. The steady-state mRNA levels of MMP-1, COL1A1 and TIMP-1 paralleled the protein levels. AFA-positive IgG did not induce Smad 2/3 phosphorylation, indicating that this transforming growth factor-β signalling pathway was not involved. IL-1 and tumour necrosis factor (TNF) neutralization did not reverse the enhanced production of MMP-1, suggesting a direct effect of AFA on fibroblasts. Finally, anti-topoisomerase-I antibodies were present in 11 of 12 AFA-negative IgG, and an anti-topoisomerase-I monoclonal antibody failed to enhance MMP-1 production, thus indicating a lack of correlation between AFA and anti-topoisomerase-I antibody. Conclusions. These results indicate that SSc antibodies binding to fibroblasts enhance matrix degradation and MMP production events that may favour inflammation but do not directly impact on fibrosis developmen