Time-varying temperature field and thermal effect of CRTS III slab track structure in curved sections under natural environmental temperature

This research develops a three-dimensional model for adjustable superelevation in curved sections of CRTS III slab track structure, incorporating intricate temperature boundary conditions. Simulations reveal the nonlinear time-varying temperature field across various lines and superelevations. Utilizing the cohesive zone model, the deformation and interface damage of structure are thoroughly explored. Key findings include: (1) Significant temperature fluctuations (25 to 55 degrees C) and vertical temperature gradients (-25 to 70 degrees C/m) are observed in the precast slab (PS). For PS and self-compacting concrete layer (SCCL), transverse temperature gradients greater than 5 degrees C/m or less than-5 degrees C/m are concentrated within 0.35 m of the edge, extending to 0.8 m for base plate; (2) Under different lines, the structure temperature near sunny side is higher than the shaded side. When the PS slope faces the sun, an increase in superelevation results in a rise in both temperature near the slope and structure's vertical temperature gradient, while the transverse temperature gradient decreases; (3) The most significant deformation disparities in PS are observed on the thin side across different lines. The increasing superelevation accentuates deformation disparities between the two sides; (4) The interface damage between PS and SCCL is located near the four corners of SCCL, which begins at 12:00-12:30 and peaks at 13:00-14:30. Under different lines, the maximum damage observed is more pronounced when the location is situated on the sunset side. For track structure lines with PS slope facing the sunrise, a decrease in superelevation intensifies the maximum interface damage.