Analysis on mechanical characteristics of CRTSII slab ballastless track structures in rectification considering material brittleness

Abstract

To analyze the influence of rectification on the CRTS Ⅱ slab ballastless track structure, ABAQUS, a Finite element software, was used to establish the mechanical analysis model of the CRTS II slab ballastless track. Consequently, the model reliability was verified by the field measurement results. The influence of different dissociation lengths, construction temperature and rectification distance on tack structure was analyzed in detail, and the mechanical properties of the structure after cracking were considered. From the systematic calculation and analysis of stress and deformation of CRTSII slab ballastless track structure during the deflection rectification process, the following research conclusions were deduced: (1) An the increase in one-time single-point deflection rectification range, resulted in a corresponding increase in the maximum rectification of track slab, CA mortar and support; (2) An the increase in the absolute value of deflection rectification temperature for one-time single-point, led to a linear increase in the maximum rectification of the track slab, CA mortar and support. The maximum rectification of support increased from 1.34 mm to 2.12 mm; (3) A maximum rectification of 1.44 mm was obtained at the CRTS II critical drop temperature of −4.4℃ specified by the code for design of concrete structures of railway bridge and culvert and the code for design of concrete structures; (4) An increase in pushing points distance from 2 m to 3 m resulted in a reduction in the maximum rectification of track slab, CA mortar and support by 1.25%, 1.28% and 1.32%, respectively. However, the tensile strain of the track slab and support was reduced by 8.72% and 12.14%. (5) Comparing the results of cracked and non-crack models, the maximum rectification of the track slab, CA mortar and support increased by 10.24%, 11.41% and 10.38%, respectively, while the maximum strain reduction of track slab, CA mortar and support reduced by 13.10%, 23.11% and 17.85%, respectively.