Comparison of the collapse frequency and failure probability of buildings

In a previous study, the collapse frequencies and associated mortalities of buildings were compiled based on various publications. The investigation showed a considerable scattering of collapse frequencies depending on the countries. In this paper, the collapse frequencies determined for buildings are compared with the results of probabilistic calculations. Such comparisons have already been carried out for bridges, dams, tunnels and retaining walls including the consideration of central estimators and standard deviations. In order to limit the scatter, the probabilities of failure for buildings were subdivided into the different causes of failure, and collapse frequencies were subdivided into different countries and geographical regions. Overall, the comparison shows that the probabilities of failure are on overage larger than the observed collapse frequencies. Furthermore, the comparison shows are large span, which is unusual for other types of structures. Of concern are the high observed collapse frequencies in various developing countries. Human error, lack of training, etc. are often cited as the cause. Should this correspond to the facts, the basic safety concept of modern building standards, which generally excludes human error, would only be applicable in these regions to a limited extent. However, the investigation includes some limitations, such as different safety targets in different standards and different years of constructions, which are not considered. Further work is required

5th International Probabilistic Workshop: 28-29 November 2007, Ghent, Belgium

These are the proceedings of the 5th International Probabilistic Workshop. Even though the 5th anniversary of a conference might not be of such importance, it is quite interesting to note the development of this probabilistic conference. Originally, the series started as the 1st and 2nd Dresdner Probabilistic Symposium, which were launched to present research and applications mainly dealt with at Dresden University of Technology. Since then, the conference has grown to an internationally recognised conference dealing with research on and applications of probabilistic techniques, mainly in the field of structural engineering. Other topics have also been dealt with such as ship safety and natural hazards. Whereas the first conferences in Dresden included about 12 presentations each, the conference in Ghent has attracted nearly 30 presentations. Moving from Dresden to Vienna (University of Natural Resources and Applied Life Sciences) to Berlin (Federal Institute for Material Research and Testing) and then finally to Ghent, the conference has constantly evolved towards a truly international level. This can be seen by the language used. The first two conferences were entirely in the German language. During the conference in Berlin however, the change from the German to English language was especially apparent as some presentations were conducted in German and others in English. Now in Ghent all papers will be presented in English. Participants now, not only come from Europe, but also from other continents. Although the conference will move back to Germany again next year (2008) in Darmstadt, the international concept will remain, since so much work in the field of probabilistic safety evaluations is carried out internationally. In two years (2009) the conference will move to Delft, The Netherlands and probably in 2010 the conference will be held in Szczecin, Poland. Coming back to the present: the editors wish all participants a successful conference in Ghent

Comparison of the Collapse Frequency and Failure Probability of Buildings

In a previous study, the collapse frequencies and associated mortalities of buildings were compiled based on various publications. The investigation showed a considerable scattering of collapse frequencies depending on the countries. In this paper, the collapse frequencies determined for buildings are compared with the results of probabilistic calculations. Such comparisons have already been carried out for bridges, dams, tunnels and retaining walls including the consideration of central estimators and standard deviations. In order to limit the scatter, the probabilities of failure for buildings were subdivided into the different causes of failure, and collapse frequencies were subdivided into different countries and geographical regions. Overall, the comparison shows that the probabilities of failure are on overage larger than the observed collapse frequencies. Furthermore, the comparison shows are large span, which is unusual for other types of structures. Of concern are the high observed collapse frequencies in various developing countries. Human error, lack of training, etc. are often cited as the cause. Should this correspond to the facts, the basic safety concept of modern building standards, which generally excludes human error, would only be applicable in these regions to a limited extent. However, the investigation includes some limitations, such as different safety targets in different standards and different years of constructions, which are not considered. Further work is required

2. Dresdner Probabilistik-Symposium – Sicherheit und Risiko im Bauwesen: Dresden, 12. November 2004

Das Dresdner Probabilistik-Symposium findet erfreulicherweise zum zweiten Mal statt. Vielleicht gelingt es den Besuchern, Vortragenden und Veranstaltern, damit eine Tradition aufzubauen. Zweifelsohne ist das Thema der Tagung ein sehr spezielles. Welcher Bauingenieur hat schon bei seiner alltäglichen Arbeit Zeit, über die Sicherheit seiner Konstruktionen nachzudenken? In der Regel hält sich der Bauingenieur an die Regeln der Technik und kann davon ausgehen, daß die Konstruktion dann die erforderliche Sicherheit erbringt. Gerade aber bei anspruchsvollen Aufgaben, Fällen, in denen der Bauingenieur gezwungen ist, eigene Modelle zu entwickeln, muß er die Sicherheit prüfen. In zunehmendem Maße versuchen Bauingenieure sich durch die Bewältigung solcher Aufgaben vom Markt abzugrenzen. Deshalb sehen wir als Veranstalter langfristig auch einen steigenden Bedarf für die Vermittlung von Grundlagen der Sicherheitstheorien im Bauwesen.... (aus dem Vorwort

2. Dresdner Probabilistik-Symposium – Sicherheit und Risiko im Bauwesen: Dresden, 12. November 2004

Das Dresdner Probabilistik-Symposium findet erfreulicherweise zum zweiten Mal statt. Vielleicht gelingt es den Besuchern, Vortragenden und Veranstaltern, damit eine Tradition aufzubauen. Zweifelsohne ist das Thema der Tagung ein sehr spezielles. Welcher Bauingenieur hat schon bei seiner alltäglichen Arbeit Zeit, über die Sicherheit seiner Konstruktionen nachzudenken? In der Regel hält sich der Bauingenieur an die Regeln der Technik und kann davon ausgehen, daß die Konstruktion dann die erforderliche Sicherheit erbringt. Gerade aber bei anspruchsvollen Aufgaben, Fällen, in denen der Bauingenieur gezwungen ist, eigene Modelle zu entwickeln, muß er die Sicherheit prüfen. In zunehmendem Maße versuchen Bauingenieure sich durch die Bewältigung solcher Aufgaben vom Markt abzugrenzen. Deshalb sehen wir als Veranstalter langfristig auch einen steigenden Bedarf für die Vermittlung von Grundlagen der Sicherheitstheorien im Bauwesen.... (aus dem Vorwort

4th International Probabilistic Workshop: 12th-13th October 2006, Berlin, BAM (Federal Institute for Materials Research and Testing)

Die heutige Welt der Menschen wird durch große Dynamik geprägt. Eine Vielzahl verschiedener Prozesse entfaltet sich parallel und teilweise auf unsichtbare Weise miteinander verbunden. Nimmt man z.B. den Prozess der Globalisierung: Hier erleben wir ein exponentielles Wachstum der internationalen Verknüpfungen von der Ebene einzelner Menschen und bis zur Ebene der Kulturen. Solche Verknüpfungen führen uns zum Begriff der Komplexität. Diese wird oft als Produkt der Anzahl der Elemente eines Systems mal Umfang der Verknüpfungen im System verstanden. In anderen Worten, die Welt wird zunehmend komplexer, denn die Verknüpfungen nehmen zu. Komplexität wiederum ist ein Begriff für etwas unverstandenes, unkontrollierbares, etwas unbestimmtes. Genau wie bei einem Menschen: Aus einer Zelle wächst ein Mensch, dessen Verhalten wir im Detail nur schwer vorhersagen können. Immerhin besitzt sein Gehirn 1011 Elemente (Zellen). Wenn also diese dynamischen sozialen Prozesse zu höherer Komplexität führen, müssen wir auch mehr Unbestimmtheit erwarten. Es bleibt zu Hoffen, dass die Unbestimmtheit nicht existenzielle Grundlagen betrifft. Was die Komplexität der Technik angeht, so versucht man hier im Gegensatz zu den gesellschaftlichen Unsicherheiten die Unsicherheiten zu erfassen und gezielt mit ihnen umzugehen. Das gilt für alle Bereiche, ob nun Naturgefahrenmanagement, beim Bau und Betrieb von Kernkraftwerken, im Bauwesen oder in der Schifffahrt. Und so verschieden diese Fachgebiete auch scheinen mögen, die an diesem Symposium teilnehmen: Sie haben erkannt, das verantwortungsvoller Umgang mit Technik einer Berücksichtigung der Unbestimmtheit bedarf. Soweit sind wir in gesellschaftlichen Prozessen noch nicht. Wünschenswert wäre, dass in einigen Jahren nicht nur Bauingenieure, Maschinenbauer, Mathematiker oder Schiffsbauer an einem solchen Probabilistik- Symposium teilnehmen, sondern auch Soziologen, Politiker oder Manager... (aus dem Vorwort) --- HINWEIS: Das Volltextdokument besteht aus einzelnen Beiträgen mit separater Seitenzählung.PREFACE: The world today is shaped by high dynamics. Multitude of processes evolves parallel and partly connected invisible. For example, the globalisation is such a process. Here one can observe the exponential growing of connections form the level of single humans to the level of cultures. Such connections guide as to the term complexity. Complexity is often understood as product of the number of elements and the amount of connections in the system. In other words, the world is going more complex, if the connections increase. Complexity itself is a term for a system, which is not fully understood, which is partly uncontrollable and indeterminated: exactly as humans. Growing from a single cell, the humans will show latter a behaviour, which we can not predict in detail. After all, the human brain consists of 1011 elements (cells). If the social dynamical processes yield to more complexity, we have to accept more indetermination. Well, one has to hope, that such an indetermination does not affect the basic of human existence. If we look at the field of technology, we can detect, that here indetermination or uncertainty is often be dealt with explicitly. This is valid for natural risk management, for nuclear engineering, civil engineering or for the design of ships. And so different the fields are which contribute to this symposium for all is valid: People working in this field have realised, that a responsible usage of technology requires consideration of indetermination and uncertainty. This level is not yet reached in the social sciences. It is the wish of the organisers of this symposium, that not only civil engineers, mechanical engineers, mathematicians, ship builders take part in this symposium, but also sociologists, managers and even politicians. Therefore there is still a great opportunity to grow for this symposium. Indetermination does not have to be negative: it can also be seen as chance

6th International Probabilistic Workshop - 32. Darmstädter Massivbauseminar: 26-27 November 2008 ; Darmstadt, Germany 2008 ; Technische Universität Darmstadt

These are the proceedings of the 6th International Probabilistic Workshop, formerly known as Dresden Probabilistic Symposium or International Probabilistic Symposium. The workshop was held twice in Dresden, then it moved to Vienna, Berlin, Ghent and finally to Darmstadt in 2008. All of the conference cities feature some specialities. However, Darmstadt features a very special property: The element number 110 was named Darmstadtium after Darmstadt: There are only very few cities worldwide after which a chemical element is named. The high element number 110 of Darmstadtium indicates, that much research is still required and carried out. This is also true for the issue of probabilistic safety concepts in engineering. Although the history of probabilistic safety concepts can be traced back nearly 90 years, for the practical applications a long way to go still remains. This is not a disadvantage. Just as research chemists strive to discover new element properties, with the application of new probabilistic techniques we may advance the properties of structures substantially. (Auszug aus Vorwort