地下结构可靠性的区间分析方法

【作者】 吴莹；

【导师】 杨成永；

【作者基本信息】 北京交通大学 ， 市政工程， 2007， 硕士

【摘要】 近年来,国内外大量的地下工程建设对地下结构的可靠性研究提出了要求。现有的传统概率方法和模糊方法,主要是在已通过大量调查获得了关于荷载和结构抗力的统计资料,并建立了相应的概率分布模型的基础上,分析结构服役期间的可靠度。但是,影响地下结构可靠性的因素很多,包括了许多随机性、模糊性和不确定性因素,很难用传统的数学、力学模型模拟。因此,现有的方法显然难以满足地下结构可靠性分析的要求。基于以上现状,本文提出了一种基于区间模型的非概率可靠性度量及分析方法。它只需知道不确定参量的界限,而不要求其具体的分布形式。因而,可大大降低对原始数据的要求和整个计算工作量。并且由于区间分析方法不涉及概率的概念,可在一定程度上克服概率可靠性所存在的缺陷。在所掌握的原始数据较少的情况下,它为结构的可靠性计算提供了一种可能的选择。本文主要介绍了区间数学的概念和区间分析的计算方法,总结了不同情况下计算非概率可靠指标的多种方法。并且把区间分析方法与传统概率方法和模糊方法进行了对比,通过算例分析和数据分析,得出区间分析方法与其它两种方法在判断结构可靠性方面基本一致的结论。在实例分析中,通过厦门东通道隧道衬砌可靠度计算这一工程实例证明了区间分析方法在可靠度分析中的有效性和实用性。最后总结了本文的主要工作内容,并对今后的研究提出了一些建议。更多还原

【Abstract】 In recent years, many more and more underground have been calling for structural reliability analysis home and abroad. But the existing methods—probabilistic method and fuzzy method are mainly based on probabilistic distributions of the variables and a large number of statistical data of load and structural resistance are needed. However, there are so many factors influencing underground project’s reliability (e.g. variables that hold randomicity, fuzzy or uncertainty) that it is almost impossible to develop a mathematical or dynamical model. So, the traditional methods can hardly satisfy the need in current reliability research.Out of the above-mentioned situation, a new method—non-probabilistic reliability measurement and analysis method based on interval model is proposed. This method only needs the bounds of variables, but their probability distributions. Consequently, the amount of the original data and calculation workload are reduced. And because probabilistic concept is not required, it bypasses some of the drawbacks of the traditional probabilistic reliability method. In condition of scarcity of original statistical data, the model provides us a good alternative for conducting structural reliability evaluation.The main wok of this paper include an introduction to the concepts of interval mathematics and computing method of interval analysis, an summarization on the non-probabilistic reliability analysis methods for different situations, and a comparison of interval analysis method with probabilistic method and fuzzy method. Analysis shows that the non-probabilistic model gives a result in consistence with other two models. Then a case study is done on a tunnel from Xiamen East Channel, which indicates that the interval analysis method is applicable in reliability analysis. Finally conclusions and remarks on future research are given.更多还原