A five-grade grading system for the evaluation and communication of short-term and long-term risk posed by natural hazards. (May 2019)

• Record Type: Journal Article
• Authors: Babič, Anže; Dolšek, Matjaž
• Is Part Of: Structural safety. Volume 78(2019)
• Page Start: 48
• Page End: 62
• Publication Date: 2019-05
• Subjects: Grading system -- Risk evaluation -- Cumulative risk -- Grade reduction -- Risk communication -- Natural hazards risk; Structural stability -- Periodicals; Safety factor in engineering -- Periodicals; Reliability (Engineering) -- Periodicals; Constructions -- Stabilité -- Périodiques; Coefficient de sécurité en ingénierie -- Périodiques; Fiabilité -- Périodiques; 620.86
• DOI: 10.1016/j.strusafe.2018.12.006
• Languages: English
• ISSNs: 0167-4730

Abstract

Highlights: A five-grade grading system to evaluate and communicate natural hazards risk is proposed. The grading system considers the concepts of long-term and short-term risk tolerance. An example is presented to illustrate the implementation of the grading system. The framework can be used as the basis for strengthening disaster risk management. Abstract: A five-grade grading system is introduced by combining together the concepts of long-term and short-term risk tolerance. Grades AA or A are related to a long-term tolerable risk, whereas grades B and C are considered acceptable only for a shorter period, depending on the facility performance, and grade D corresponds to a short-term intolerable risk. In the first step of the grading process, the initial grade is determined by comparing the estimated risk to a set of risk boundaries, which define the ranges between grades AA-A, A-B and B-C. If the estimated risk is found to be long-term intolerable (grade B or C), the second step follows. This approach utilizes the criterion of cumulative risk, which makes it possible to introduce a reduction in grades B or/and C over time, and in the additional grade D, which is associated with intolerable cumulative risk. The use of the proposed grading system is demonstrated by means of an example of two precast reinforced concrete buildings exposed to seismic risk, where grade B is initially assigned to the facility with better performance, whereas the other facility is evaluated by grade C. It is shown that the reduction of the grades to the lowest grade D is scheduled for 11.9 years and 3.8 years, respectively, in the case of the building with the lower and the higher risk. Such information can be used for communicating risk to stakeholders, and as a basis for the enhancing of the disaster risk management of communities.