Fuzzy-Random Analysis for Instability Risk Rate of Concrete Gravity Dams

In this paper, a evaluation model used to analyze the fuzzy-random instability risk rate of concrete gravity dams is established based on the theory of fuzzy mathematics. The fuzzy-randomness of concrete gravity dam instability influencing factors and the fuzziness of instability criterion can be considered simultaneously in the evaluation model. Then, the determination method of instability area, instability membership function and PDF of instability performance function is researched; the computational expression and indexes of fuzzy-random instability risk rate are established. Besides, the calculation method of fuzzy-random instability risk rate is proposed considering the time-varying effect of concrete gravity dam instability influencing factors comprehensively. The example analysis shows that the analysis result of fuzzy-random instability risk rate reflects the reality much more objectively.