基于模糊集理论的海塘稳定可靠度研究

针对海塘边坡稳定性分析中因忽略参数空间变化等因素产生的分析结果偏于不安全的倾向,提出了一种计算模糊随机可靠度的简化方法.首次引入"正态模糊数"来描述所选重要参数的计算区间,采用简化Bishop法与"模糊顶点法"相结合的方法计算边坡稳定的安全系数密度函数,然后根据大量边坡实例统计结果的构造函数得到安全系数的戒下型隶属函数,最终计算获得边坡稳定的模糊随机可靠度评价.结果分析表明,传统可靠度分析结果偏于不安全,而利用模糊随机可靠度来评价边坡稳定状况更趋于合理性.

Reliability analysis for slope stable capacity based on fuzzy probability

To investigate the randomness and vagueness implicit in the slope stability analysis,a new approach using fuzzy-random reliability is developed to analyze the stability of engineering slopes.The Simplified Bishop method is adopted to calculate the safety factor of slopes,and a fuzzy method called "normal fuzzy set" is introduced for the first time to describe the fuzzy parameters which were chosen according to their importance in Simplified Bishop method and to calculate the credibility function of safety factor.A membership function called guard-down function is constructed according to statistical data from actual slopes.And the fuzzy-random reliability of slope stability was finally obtained.It is found that results of the traditional reliability method are less securable and those of fuzzy-random reliability method are more reasonable.