APPROACHES, ILLUSTRATIVE FINDINGS AND RECOMMENDATIONS IN TSUNAMI RISK AND FRAGILITY MODELING

摘要

A general framework for tsunami probabilistic risk analysis (TPRA) is outlined, and concise descriptions of probabilistic tsunami hazard assessment (PTHA) and tsunami fragility analysis (TFA) are given. Two specific details of PTHA and TFA are then elaborated: (1) Calibration of tsunami wave models in PTHA; procedure and motivation for statistical, versus deterministic, model calibrations are explained. (2) A fundamental TFA approach adapted from existing methodology for seismic fragility analysis; illustration of the TFA approach is provided via parameter study using a simple physical, nonlinear structural-mechanics model. In describing the TFA parameter study, wave characteristics, issues and solutions potentially useful to TFA studies for more realistic physical models are highlighted, including: (a) valid engineering characterization of tsunami waves; (b) representative values of fragility (i.e., capacity probability distribution) parameters; and (c) influences of wave rise time (as simple descriptor of wave dynamics), the structure's governing lateral load in terms of seismic design basis, and variation in structural yield strength. Lastly, some conclusions are provided, with a summary of key general recommendations and needs for further development in TPRA.