Research on the Bridge Tower Crack Propagation under Thermal Fatigue Loading

The bridge tower crack extension probability is very large because of the stress concentration at the crack tip, combined with the fatigue stress. Based on the long-term observations of temperature fatigue load spectrums of a bridge tower and the experiment of concrete fatigue performance parameters, the problem of crack propagation is analyzed by infinite life safety reliability model and safe and reliable crack extension randomness model. It is concluded that the concrete structure crack extension probability is close to 98.6% and reasonable repair cycle should be about 3 years.