ISO 2394:2015

INTERNATIONAL ISO
STANDARD 2394
Fourth edition
2015-03-01
General principles on reliability for
structures
Principes généraux de la fiabilité des constructions
Reference number
©
ISO 2015
© ISO 2015
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Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Terms and definitions . 1
2.1 General terms . 1
2.2 Terms related to design and assessment . . 5
2.3 Terms related to actions, action effects, and environmental influences . 8
2.4 Terms related to structural response, resistance, material properties, and
geometrical quantities .11
3 Symbols .12
3.1 General .12
3.2 Latin upper case letters .12
3.3 Latin lower case letters.13
3.4 Greek letters .13
3.5 Subscripts .14
4 Fundamentals .14
4.1 General .14
4.2 Aims and requirements to structures .14
4.2.1 Fundamental requirements to structures .14
4.2.2 Target performance level .15
4.3 Conceptual basis .16
4.3.1 Decisions concerning structures .16
4.3.2 Structural performance modelling .17
4.3.3 Uncertainty and treatment of knowledge .17
4.4 Approaches.18
4.4.1 General.18
4.4.2 Risk-informed and reliability-based approaches .18
4.4.3 Semi-probabilistic approaches .20
4.5 Documentation .20
5 Performance modelling .21
5.1 General .21
5.1.1 Structural performance and limit state concept.21
5.1.2 Performance and performance indicators .21
5.1.3 Basic performance requirement and design situations .21
5.1.4 Levels of verification.21
5.2 Performance model .22
5.2.1 General.22
5.2.2 Time-dependent aspects .22
5.2.3 System aspects .22
5.3 Limit states .23
5.3.1 Ultimate limit state .23
5.3.2 Serviceability limit states .23
5.3.3 Condition limit states .24
5.3.4 Limit state function.24
Contents Page
6 Uncertainty representation and modelling .25
6.1 General .25
6.1.1 Types of uncertainty .25
6.1.2 Treatment of uncertainty .26
6.1.3 Interpretation of probability .26
6.1.4 Probabilistic models .26
6.1.5 Population/outcome space .26
6.1.6 Hierarchical modelling of uncertainty .27
6.2 Models for structural analysis .27
6.2.1 General.27
6.2.2 Actions and environmental influences .28
6.2.3 Geometrical properties .30
6.2.4 Material properties .30
6.2.5 Responses and resistances .31
6.3 Models for consequences .33
6.4 Model uncertainty .34
6.5 Experimental models .34
6.6 Updating of probabilistic models .35
7 Risk-informed decision making .35
7.1 General .35
7.2 System identification .35
7.3 System modelling .36
7.4 Risk quantification .36
7.5 Decision optimization and risk acceptance.36
8 Reliability-based decision making .37
8.1 General .37
8.2 Decisions based on updated probability measures .38
8.3 Systems reliability versus component reliability .38
8.4 Target failure probabilities .39
8.5 Calculation of the probability of failure .39
8.5.1 General.39
8.5.2 Time-invariant reliability problems .40
8.5.3 Transformation of time-variant into time-inva
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