13.1 Introduction
In the foregoing chapters, the fundamental aspects of risk and reliability in civil engineering
have been discussed. Starting with an overview of the incidents and failures, having occurred
in the past, the detailed aspects of how in a quantitative and consistent manner may the
reliability and/or the risk associated with engineering activities be assessed and controlled,
have been discussed. To this end taking basis on the theory of the probability and Bayesian
statistical analysis, the classical tools for the analysis of logical trees and the classical
reliability analysis of technical components have first been introduced. Thereafter the theory
of structural reliability, the concepts of and tools for Bayesian decision analysis have been
introduced and finally some principal applications in the area of structural reliability have
been discussed.
However, one issue has still not been touched upon in any detail despite its important role in
the problem framework, namely the question “how safe is safe enough”, i.e. what
requirements should be fulfilled in regard to the safety associated with the activities analysed
and which are the fundamental principles that need to be taken into account when assessing
the acceptability of risks.
Fundamental societal value settings
Before entering into this problem complex it is worthwhile to recognise that the problem has a
fundamental and philosophical bearing to the rights of human beings. The United Nations
Office of the High Commissioner of Human Rights regulates the rights of humans by the
“Universal Declaration of Human Rights”. The full text may be found on the United Nations
web-page: http://www.unhchr.ch/udhr/lang/eng.htm but here three of the relevant articles are
given for easy reference.
Article I
All human beings are born free and equal in dignity and rights. They are endowed with reason
and conscience and should act towards one another in a spirit of brotherhood.
Article 3
Everyone has the right to life, liberty and security of person.
Article 7
All are equal before the law and are entitled without any discrimination to equal protection of
the law. All are entitled to equal protection against any discrimination in violation of this
Declaration and against any incitement to such discrimination.
The articles emphasise both the morally and juristically obligation to consider all persons as
being equals and furthermore underlines the rights to personal safety for all individuals.
Therefore whatever criteria are formulated in regard to the acceptable risks it should always
kept in mind that the abovementioned fundamental principles of the human rights are not
violated thereby.