深厚冲积层钢筋混凝土外层井壁结构模糊随机有限元可靠性及灵敏度分析

Fuzzy random finite element reliability and sensitivity analysis of reinforced concrete outer shaft lining structure in deep alluvium

基于模糊随机有限元的基本原理及方法,对结构失效函数和材料本构关系作等效模糊化处理,设定输入输出模糊随机变量,建立钢筋混凝土外层井壁结构的模糊随机有限元分析模型。利用ANSYS数值计算外层井壁结构的模糊随机有限元可靠性,结果表明:由于综合考虑到各变量参数的不确定性,获得的模糊随机有限元可靠性相比常规的有限元可靠性总体偏低,其结果更能反映实际工况。此外,模糊随机有限元可靠性以区间值表征不同井段的可靠程度,较常规可靠性的定值表现方法更具工程针对性。模糊随机有限元灵敏度分析发现:影响外层井壁结构可靠性的重要因素依次是井壁冻结压力、混凝土抗压强度和厚径比。通过ANSYS灵敏度散点图可指明主要输入变量的变动对输出变量的影响程度以及变量需改动的大致区间范围。

Based on the basic principle and method of fuzzy random finite element, the structural failure function and material constitutive relation were blurred equivalently. Setting the input and output of fuzzy random variables, the fuzzy random finite element analysis model of reinforced concrete structure of outer shaft lining was established. The AN- SYS was used to calculate the fuzzy random finite element reliability of shaft lining structure. The results show that the fuzzy random finite element reliability is generally low compared with the conventional finite element reliability for the consideration of uncertainty of variable parameters, thus it better reflects the engineering conditions. In addition, the fuzzy random finite element reliability with the characterization of interval value is more reasonable than the conventional reliability method of fixed value manifestation. Fuzzy random sensitivity analysis manifests that the important in- fluencing factors to outer shaft lining structure reliability are in accordance with the order of shaft freezing pressure, concrete compressive strength and thickness to diameter ratio. The ANSYS sensitivity scatterplot can indicate the influence relationship of main input variables to output variables, and the general range of variables change.