Research on correlation of modal frequency of long-span bridge structures and environmental temperature

The space analysis model of the Runyang Cable-stayed Bridge and Suspension Bridge are established to perform modal analysis at different simplified environment temperature and to compare with the analysis result of the collected data from the safety monitoring of the Runyang Bridge when identification of the modal frequency are greatly affected by change of environment temperature. The results of the study show as follows: The relationship between temperature and modal frequency of both Runyang Cable-stayed Bridge and Suspension Bridge is negative correlation. Frequency of vertical bending model decreases gradually as the temperature grows. Frequency of high order model of the mid-span vertical bending of the Runyang Suspension Bridge have more notable influence than that of low order model while the Runyang Cable-stayed Bridge decreases. The related conclusion is beneficial to eliminate the effect of temperature on identification of the modal frequency.