基于逆可靠度法的大跨悬索桥主缆安全系数评估

Main Cable Safety Factors Assessment of Long-span Suspension Bridges Based on Inverse Reliability Method

提出了一种基于逆可靠度法的大跨悬索桥主缆安全系数评估方法。该方法通过给定结构的目标可靠度指标反求主缆安全系数，计算出的主缆安全系数既考虑了结构参数中不确定因素的影响，又满足了预先给定的主缆可靠度水平。运用该方法评估了主跨跨径范围为2000--5000m的悬索桥主缆安全系数。结果表明，参数的不确定性对悬索桥主缆安全系数会产生较大影响，忽略参数不确定性的影响会导致过高地估计主缆安全系数。

Authors presented main cable safety factors assessment of long-span suspension bridges based on inverse reliability method. This method which both considered influence of uncertainty factors among structure parameters and satisfied prescribed main cable reliability level was used to get inverse main cable safety factors through target reliability indexes. Main cable safety factors of suspension bridges with main span ranging from 2 000 m to 5 000 m were estimated using the proposed method. The results show that parameters uncertainty has a major effect on main cable safety factor of suspension bridges. Ignoring parameters uncertainty will produce overestimation of main cable safety factors.