基于广义随机空间的护面块体稳定性概率分析

Probability analysis of armour stability based on generalized random space

文章应用基于广义随机空间的可靠度计算方法,开展了护面块体稳定性的概率分析。护面块体稳定性计算公式的敏感性分析结果表明,Van de Meer公式的不确定性主要来自与波浪条件相关的客观变量,公式自身的敏感性较小,而Hudson公式的不确定性主要来自公式本身的随机性。概率分析表明,护面块体稳定性的影响因素包括设计波高、使用期限、破坏水平、名义直径等,工程设计中可采用基于可靠度的风险评估方法,通过设计参数的不同组合来获得全生命周期费用效益比最优的设计方案。设计变量的相关性对结构的可靠度有一定影响,目前的工程设计对此考虑不足,可能低估失效概率和风险损失,应加强研究。

The probability analysis of armour stability was performed based on reliability calculation in generalized random space.Sensitivity analysis on the armour stability formulas shows that the uncertainty of Van de Meer formula mainly comes from objective variables related to wave conditions and the sensitivity of the formula itself is small.However,the uncertainty of Hudson formula mainly comes from the randomness of the formula itself.Probability analysis shows that the factors affecting the stability of armour units include design wave height,lifetime,damage level,and nominal diameter,etc.In engineering design,the reliability-based risk analysis can be used to obtain the optimal scheme with the best lifetime cost-profit ratio through the combinations of design parameters.The correlation between random design variables has a considerable impact on structural reliability,which means significantly underestimated failure probability and risk loss of structures in the present engineering design.