TEMPERATURE SIMULATION AND THERMAL EFFECT RESEARCH ON EXTREMELY LONG-SPAN CONCRETE FRAME STRUCTURE

To investigate the temperature loading of an extremely long-span concrete structure under complex environment and hydration effects, a simulation method of a concrete temperature field has been proposed. The method can simulate the effect of environmental temperature change, of solar radiation, and of hydration heat of concrete simultaneously. Temperature field monitoring was carried out based on the extremely long-span concrete structure of the Xiamenbei Railway Station. The accuracy of temperature simulation method proposed was verified by the monitoring data. With the temperature loading at different stages determined, the calculation method of thermal stress has been put forward. After that, the stress results under different post-cast zone schemes were simulated to determine the appropriate crack control method. The test results show that the temperature simulation method proposed can reflect the actual results. The temperature peak during hydration is about 50 ℃, and the local annual temperature difference during operation stage is 25.3 ℃. The retention time and closure season of post-cast zone affect the final stress caused by temperature and shrinkage. As to the extremely long-span concrete structure, a retention time of 60 days and the closure season of winter are suggested to control the cracking.