Structural Condition Assessment and Temperature Effect Analysis of Cable–Pylon Anchorage Zone Using Long-Term SHM Data

Abstract

To study the temperature effect in the anchorage zone of a long-span cable-stayed bridge, a wavelet multiresolution analysis and layered stripping method were used in this paper. Based on long-term structural health monitoring data, the signals were decomposed and reconstructed at multiple time scales, confirming temperature to be the main factor causing the stress change in the anchorage zone. The results of structural condition during operation showed that the general compressive stress level of the anchorage zone was low. However, the tensile stress level of the sidewall was high, which led to a severe concrete cracking. Excluding the influence of the seasonal temperature, the compressive stress increased slightly, the horizontal tensile stress in the upstream inner pylon wall increased, and the crack width increased gradually. By analysing the daily temperature effect on the upstream and downstream pylon walls, the regression model proposed in this study can be used to predict the daily temperature effect at any time in the diurnal cycle. The accuracy of the model is reliable within 6 days, but for the location of severe cracks, the monitoring data should be updated in real time to ensure the precision.