Severe Earthquakes (severe + earthquake)

Distribution by Scientific Domains

Selected Abstracts

Erdbebenertüchtigung des Feuerwehrgebäudes in Basel durch schwimmende Lagerung

BAUTECHNIK, Issue 8 2009
Hugo Bachmann Prof. Dr. sc. techn.
Baumechanik; Bauwerkserhaltung/Sanierung; Structural Mechanics; Maintenance and Renovation Abstract Kürzlich wurde das Hauptgebäude der Berufsfeuerwehr Basel-Stadt aus dem Jahre 1943 auf spezielle Erdbebenlager aus Gummi und auf Gleitlager gestellt. Es handelt sich um die erste derartige Erdbebenertüchtigung eines bestehenden Gebäudes nördlich der Alpen. Im Vergleich zu einer konventionellen Verstärkung waren die Baukosten bedeutend geringer, und es war keine temporäre Ausquartierung des Betriebes in ein teures Provisorium erforderlich. Zudem ist die resultierende Erdbebensicherheit erheblich größer und die Schadensanfälligkeit bei schweren Erdbeben wesentlich geringer als es bei einer konventionellen Verstärkung der Fall wäre. Seismic upgrading of the fire brigade building in Basel by base isolation. Recently, the main building of the professional fire brigade of the city and canton Basel-Stadt built in the year 1943 was placed on special seismic elastomeric bearings and on sliding bearings. This is the first such seismic upgrading of an existing building in the north of the Alps. Compared to a conventional strengthening the buildingcosts were significantly smaller, and no temporary transfer of the operation into an expensive provisional building was necessary. Moreover, the resulting seismic safety is considerably higher and the vulnerability to a severe earthquake essentially smaller than in case of a conventional strengthening. [source]

Psychological effects of the November 1999 earthquake in Turkey: an epidemiological study


Objective: This study assessed the traumatic stress symptoms and related factors in two towns affected by two earthquakes, which killed 20 000 people in 1999 in Turkey. Method: A total of 430 people in selected households were seen 18 months after the earthquake. They were given a self-report questionnaire assessing post-traumatic stress (PTSD) and depressive symptoms, demographics and trauma exposure. Results: The rates of PTSD and depression were higher in the site closer to the epicenter. The traumatic stress symptom checklist scores were predicted by fear during earthquake, loss of friends and neighbours, female gender, lower education and living in rented accomodation. Depression was predicted by study site, death of relatives and past psychiatric illness. Conclusion: These results show that severe earthquakes can cause long-lasting morbidity. Our previous findings that showed a differential prediction for depressive and traumatic stress symptoms after earthquakes are also supported. [source]

Seismic design of RC structures: A critical assessment in the framework of multi-objective optimization

Nikos D. Lagaros
Abstract The assessment of seismic design codes has been the subject of intensive research work in an effort to reveal weak points that originated from the limitations in predicting with acceptable precision the response of the structures under moderate or severe earthquakes. The objective of this work is to evaluate the European seismic design code, i.e. the Eurocode 8 (EC8), when used for the design of 3D reinforced concrete buildings, versus a performance-based design (PBD) procedure, in the framework of a multi-objective optimization concept. The initial construction cost and the maximum interstorey drift for the 10/50 hazard level are the two objectives considered for the formulation of the multi-objective optimization problem. The solution of such optimization problems is represented by the Pareto front curve which is the geometric locus of all Pareto optimum solutions. Limit-state fragility curves for selected designs, taken from the Pareto front curves of the EC8 and PBD formulations, are developed for assessing the two seismic design procedures. Through this comparison it was found that a linear analysis in conjunction with the behaviour factor q of EC8 cannot capture the nonlinear behaviour of an RC structure. Consequently the corrected EC8 Pareto front curve, using the nonlinear static procedure, differs significantly with regard to the corresponding Pareto front obtained according to EC8. Furthermore, similar designs, with respect to the initial construction cost, obtained through the EC8 and PBD formulations were found to exhibit different maximum interstorey drift and limit-state fragility curves. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Seismic performance evaluation of steel arch bridges against major earthquakes.

Part 1: dynamic analysis approach
Abstract In this study the inelastic behavior of steel arch bridges subjected to strong ground motions from major earthquakes is investigated by dynamic analyses of a typical steel arch bridge using a three-dimensional (3D) analytical model, since checking seismic performance against severe earthquakes is not usually performed when designing such kinds of bridge. The bridge considered is an upper-deck steel arch bridge having a reinforced concrete (RC) deck, steel I-section girders and steel arch ribs. The input ground motions are accelerograms which are modified ground motions based on the records from the 1995 Hyogoken-Nanbu earthquake. Both the longitudinal and transverse dynamic characteristics of the bridge are studied by investigation of time-history responses of the main parameters. It is found that seismic responses are small when subjected to the longitudinal excitation, but significantly large under the transverse ground motion due to plasticization formed in some segments such as arch rib ends and side pier bases where axial force levels are very high. Finally, a seismic performance evaluation method based on the response strain index is proposed for such steel bridge structures. Copyright © 2004 John Wiley & Sons, Ltd. [source]