In order to evaluate the fatigue performance of a steel anchor box (SAB) under large-amplitude stay cable vibration, Finite Element (FE) analysis was carried out to identify the fatigue-prone details on SAB. Then wind conditions, vibration of the cable and stress at the SAB were simultaneously monitored in field and analyzed. The observed multi-mode, high-order vortex-induced vibration (VIV) produced extremely low stress in the SAB. Therefore, its fatigue effects on the SAB are negligible within the monitored one-month period and 2-9 m/s deck wind speeds for this configuration. Passing trucks generated significantly large number of loading cycles, but stress ranges were notably low. Although daily thermal action only created one stress cycle, it was sensitive to stress concentration and created a significantly large stress range in the SAB. As a result, excluding thermal effects at measured stress will lead to an overestimated fatigue life of the SAB. Even if the stay cable experiences largeamplitude VIV, fatigue will not be a concern for the SAB under joint action of VIV force, truck loading and thermal effects in-service condition.
Zhu et al. (Sat,) studied this question.