Temperature field simulation of early-age ballastless track base plate under influence of environmental factors

In order to realize the accurate response of temperature field of early-age ballastless track, a concrete hydration heat release model based on equivalent age method was proposed. Firstly, early heat transfer process of base plate was analyzed, and the key influencing factors of early temperature field were clarified. Secondly, according to theory of equivalent age maturity of concrete, early temperature field analysis model of base plate based on equivalent age method was established. Thirdly, based on the subroutine development function of finite element software, comprehensive real simulation of various factors in analysis model was realized by self-compiled program. These factors include equivalent age hydration heat release, convective heat transfer, solar radiation, base temperature, etc. Finally, early thermal performance differences between equivalent age method and traditional non-equivalent age method under the influence of various environmental factors were compared and analyzed. The results show that the solar radiation has the most significant influence on the early temperature field of the base plate among the influencing factors. In the finite element model, the early temperature of the base plate simulated by the equivalent age method is generally higher than that by the non-equivalent age method, and the temperature rise range is 2−6 ℃. The use of equivalent age method in the model effectively improves the simulation accuracy of thermal properties such as hydration heat release rate, cumulative heat release and temperature of the base plate, with an improvement range of 2%−10%. In conclusion, the equivalent age method has great advantages in the simulation of early temperature field of ballastless track. © 2024 Central South University of Technology. All rights reserved.