Damage distribution and mechanical properties analysis of CRTS III slab track under uneven subgrade settlement

Abstract

Due to the complex geological conditions along the high-speed railway, the subgrade uneven settlement (USS) is inevitable, and the safety and stability of the railway are significantly affected. In this paper, a three-dimensional solid model of the CRTS III slab track is established. Based on the concrete damaged plasticity (CDP) model, the influence of USS on structural damage, deformation, stress, and gap is analyzed. Simultaneously, as a reinforced concrete structure, the structure reinforcement is an essential part of strengthening its tensile capacity. Consequently, the distribution of internal reinforcement is considered in detail, and the influence of reinforcement on the mechanical properties of the track structure is further explored. The results show that the base plate is the most vulnerable component under the USS, and its primary damage locations are the middle and edge of the USS and the middle track slab edge. The next component that is susceptible to damage is the self-compacting concrete, whose primary damage locations are the longitudinal outer side of the limit lug boss and the USS middle. The damage of each component increases monotonically with increasing settlement amplitude, first increasing and then decreasing with increasing wavelength, especially noting the cases of L = 15–20 m, which is the most unfavorable wavelength range for most amplitudes. The difference between the results under the CDP and linear elastic models increases with the increase in damage. The reinforcement significantly influences the value, range, and location of the structural concrete damage. The component of load-bearing stress shifts from concrete to reinforcement at severe damage locations.