Efficient seismic risk analysis of gravity dams via screening of intensity measures and simulated non-parametric fragility curves

Abstract

The computational cost of nonlinear numerical simulation of gravity dams brings resistance to the popularization of seismic risk analysis under the framework of Performance-based Earthquake Engineering. Insufficient seismic records and inappropriate parametric fragility models will mislead the assessment of structural performance and total risk. A computationally efficient methodology suitable for a large number of seismic waves is proposed based on screening for intensity measures and a surrogate model to obtain the non-parametric fragility curves. It specifically integrates the rigorous numerical technique of seismic damage to the dam-reservoir-foundation system, the comprehensive comparison of intensity measures, the surrogate model for classification of limit states, and the seismic risk analysis of gravity dams. A typical high gravity dam and a classical artificial neural network model are employed to illustrate the effectiveness of the proposed methodology through a step-by-step scheme. The result shows that the simulated non-parametric fragility curves are more competent to consider the uncertainty of ground motions. The obtained structural fragility and risk is more accurate than the conventional method.