Risk-Informed Mean Recurrence Intervals for Updated Wind Maps in ASCE 7-16.

Area of Science:

• Structural Engineering
• Wind Engineering
• Risk Analysis

Background:

• ASCE 7 standards are evolving towards risk-informed design and performance-based engineering (PBE).
• Previous ASCE 7-10 wind maps used specific return periods for different risk categories.
• Risk targets for essential facilities (Risk Categories III and IV) differ in PBE.

Purpose of the Study:

• To validate ASCE 7-10 return periods for PBE using updated wind load data.
• To establish a new risk-based return period for Risk Category IV structures.
• To assess the reliability of updated wind load combinations against gravity load combinations.

Main Methods:

• Reliability analyses were performed using updated wind load data.
• Wind tunnel test data for the wind directionality factor (Kd) was incorporated.
• Comparison of reliabilities between wind and gravity load combinations for Risk Category II structures.

Main Results:

• Updated wind data confirmed the appropriateness of some ASCE 7-10 return periods for PBE.
• New ASCE 7-16 wind maps feature return periods of 300, 700, 1,700, and 3,000 years for Risk Categories I, II, III, and IV, respectively.
• Reliabilities for Risk Category II structures under wind loads are consistent with those under gravity loads.

Conclusions:

• The ASCE 7-16 wind maps achieve the reliability targets outlined in Section 1.3.1.3 for non-hurricane wind loads.
• The updated approach enhances the consistency of wind load requirements with risk-informed PBE goals.
• The study provides a foundation for future refinements in wind engineering standards.