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针对桥梁疲劳损伤累积过程中的大量不确定性因素,基于Miner线性累积损伤理论提出车辆荷载作用下大跨斜拉桥的疲劳可靠度评估方法。通过“影响面”计算得到车辆荷载作用下各斜拉索的时点应力,采用“雨流计数法”统计斜拉索的应力幅和循环次数。在此基础上,对车辆荷载作用下斜拉索的疲劳可靠度进行分析。结果表明:斜拉索应力随机过程可采用Poisson过程描述;车辆荷载作用下的斜拉索疲劳可靠指标为7.19~17.57,靠近索塔处的斜拉索疲劳可靠指标较大,远离索塔处的斜拉索疲劳可靠指标较小。
Aiming at a large number of uncertainties in the process of fatigue damage accumulation of bridges, a fatigue reliability assessment method for long-span cable-stayed bridges under vehicle loads is proposed based on Miner’s linear cumulative damage theory. The stress of each stay cable under vehicle load is calculated by calculating the “influence surface”, and the stress amplitude and the number of cycles of the stay cable are calculated by using “rain flow counting method”. On this basis, the fatigue reliability of stay cables under vehicle load is analyzed. The results show that the stochastic process of cable stress can be described by Poisson process. The fatigue reliability index of cable stayed cable under vehicle load is 7.19 ~ 17.57. The fatigue reliability index of cable stayed near the cable tower is larger, Oblique cable fatigue reliability index smaller.