Robust seismic fragility curves for concrete gravity dams incorporating
aleatory, epistemic, and fuzzy uncertainties
Thulfiqar S. Hussein a,b, Mariyana Aida Ab Kadir b,c, Saif Alzabeebee a,*,
Suraparb Keawsawasvong d, M.Z. Ramli b,c, Thulfikar Razzak Al-Husseini e
a Department of Roads and Transport Engineering, University of Al-Qadisiyah, Al Diwaniyah 58002, Iraq
b Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia
c Institute of Noise and Vibration, Universiti Teknologi Malaysia, 54100 Kuala Lumpur, Malaysia
d Research Unit in Sciences and Innovative Technologies for Civil Engineering Infrastructures, Department of Civil Engineering, Thammasat School of Engineering,
Thammasat University, Pathumthani 12120, Thailand
e Department of Civil Engineering, University of Al-Qadisiyah, Al Diwaniyah 58002, Iraq
A R T I C L E I N F O
Keywords:
Seismic fragility
Concrete gravity dams
Aleatory uncertainty
Epistemic uncertainty
Fuzzy uncertainty
Finite Element Modeling
A B S T R A C T
Concrete gravity dams are critical infrastructure assets, and their failure in seismically active regions poses
significant risks. The primary problem addressed in this research is the need for a reliable assessment of the
seismic fragility of these dams to ensure safety in such areas. The research aims to develop a comprehensive
methodology for seismic fragility analysis that accounts for various uncertainties affecting dam performance,
including uncertainties in material properties and seismic characteristics and the fuzziness of damage state
thresholds through the Latin Hypercube Sampling method. The methodology involves a three-stage approach:
first, a finite element model is created using Abaqus software, incorporating uncertainties in material properties
and earthquake characteristics using the Latin Hypercube Sampling method (LHS). Second, incremental dynamic
analysis (IDA) defines damage states based on concrete cracking severity and overall stability, utilizing four
performance categories of limit states (minor, moderate, extensive, and heavy). Finally, a mathematical model is
introduced to characterize the ambiguity in damage state thresholds, recognizing the gradual nature of damage
evolution. The primary findings demonstrate that fuzziness substantially influences the probability of exceedance
across all damage states, with varying effects on different damage indices because of their differing frequency
distributions. This research enhances the reliability and accuracy of seismic fragility assessments, contributing to
more robust design guidelines and effective risk mitigation strategies for concrete gravity dams.

Robust seismic fragility curves for concrete gravity dams incorporating1