Early-age humidity and shrinkage of double-block ballastless track in coastal environment
In order to study the characteristics of humidity field and shrinkage strain in the casting early stage of double-block ballastless track structure on bridge in coastal environment,finite element model was established based on ABAQUS subroutine HETVAL to study the form of humidity and humidity gradient distribution and calculate the distribution law of shrinkage strain of track slab.The results show that:1)The maximum values of vertical and horizontal humidity gradients of the base plate are 0.68% /mm and 0.202% /mm respectively during the sprinkling maintenance period;the area which is more influenced by environmental humidity is buried 90 mm in depth,and the internal humidity of the base plate tends to be consistent at the age of 28 d.2)The relative humidity of the sleeper gradually decreases with the increase of age,and the humidity of the sleeper is basically the same at the 56th day of pouring.3)The maximum vertical and horizontal humidity gradients of the sleeper surface are 1.64% /mm and 0.59% /mm respectively after the track slab is poured;the humidity of the double-block ballastless track is basically the same after the track slab pouring for 35 d.4)The maximum free shrinkage strain at the interface of sleeper and track slab is 270.58×10-6 in the sprinkling maintenance stage.In the natural maintenance stage,the shrinkage strain shows fluctuating distribution due to the influence of atmospheric humidity.The shrinkage strain at the surface of track slab in the humidity saturation period accounts for 58.21% of the total shrinkage strain.
coastal environmentdouble-block ballast less trackearly-age humidityshrinkage strain
万方数据
维普
