盐渍土输电铁塔基础耐久性可靠度敏感性研究

Research on reliability sensitivity of transmission tower foundation durability in saline soil

建立盐渍土条件下的输电铁塔基础耐久性预测模型,采用基本灵敏度因子定义相对均值和均方差灵敏度因子;以哈密南-郑州±800k V直流特高压线路为背景,计算了其中甘3标段某斜柱式基础耐久性可靠度对基础结构、混凝土材料、配筋、基础施工、外界环境等随机变量的相对均值和均方差灵敏度因子。一方面,通过对比各灵敏度因子,研究了各随机变量对基础耐久性可靠度的敏感性,为基础耐久性设计提供指导;另一方面,通过讨论相对均方差灵敏度因子,结合基础耐久性可靠度指标相对误差,给出了将随机变量视为确定性变量以减少模型中随机变量维数的判定方法,避免传统重复试算的繁琐。

Based on durability prediction function for transmission tower foundation, relative mean and standard deviation sensitivity factors are defined, which aims at characterizing the effects on foundation durable reliability caused by variability of random variables of saline soil. The sensitivity factors of durability reliability to the random variables such as infrastructure, materials, reinforced concrete, construction and external environment of an inclined footing foundation in Gan 3 Section are calculated and analyzed. Firstly, the impacting degree and law of the random variables to durability reliability by comparing the results of sensitivity factors are studied. Secondly, a further discussion of the relative standard deviation sensitivity factor is conducted, and a judging method for reducing the dimension of random variables is proposed, combing with durability reliability index relative error, which provides guidance for the durability design of transmission tower foundation.