Push Plate Test of CRTS II Slab Ballastless Track: Theoretical Analysis, Experiments, and Numerical Simulation

Abstract

Push plate test is a powerful tool to evaluate the interfacial bond performance of China railway track structure type-II slab ballastless track structure (CRTS II SBTS). However, there is still a lack of theoretical explanation of the push plate test. In this paper, a linear proportional distribution method is proposed in terms of a series of analytical formulas to describe the interfacial force-displacement variation of CRTS II SBTS in different damage stages of the horizontal push plate test. The force-displacement relationship established by the linear proportional distribution method agrees well with that observed in full-scale test. The horizontal push plate test is then simulated, in which a bilinear cohesive zone model (CZM) was adopted to simulate the interface within track structure. The parameters of the CZM are calculated based on the force-displacement curves obtained from scale push plate test. Particularly, the normal cohesive parameters are determined based on the scale vertical push plate test instead of the traditional splitting tensile test. The simulation proves that both the maximum affected length in the undamage stage and the maximum damaged length in the damage stage depend rather on the interfacial stiffness and the material parameters of SBTS than the horizontal load. These two lengths given by the simulation are close to those defined by the proposed linear proportional distribution method. This indicates the reliability of the proposed method and the capability of scale push plate test in determining cohesive parameters.

Line Shape Analysis and Dynamic Response of Ballastless Track during Jacking Rectification Fixing

“…The overall size of the model is shown in Figure 2c, and the wide-narrow joint are distributed in the model as shown in Figure 2d. The rectification technology of the CRTS II slab ballastless track in the subgrade section is divided into two types [4][5][6]: mechanical rectification and grouting rectification. Mechanical rectification is mainly lifting the track by jack and then using the horizontal jack for lateral rectification of track slab, and finally fill polymer grouting material in the lifting gap; the implementation of grouting rectification technology relies on the reasonable arrangement of grouting lifting holes and grouting holes, releasing the constraint (dissociation) between the base plate and subgrade bed through temporary debonding agent, and then through lateral jacking to realize the rectification of track structure, as shown in Figure 1c.…”

Study on Temperature Force Control Mechanism of CRTSⅡ Slab Track: Control Conditions of Temperature Cracking

“…Cohesive zone model, fatigue endurance algorithm (FE-SAFE) and extended finite element methods (XFEM) [10][11][12][13] were introduced to analyse the interface damage; then interlayer mix mode cracking analysis model, interface fatigue model were developed based on cohesive model [14,15], which can further reveal the mechanism of interface damage. Interface test of concrete-CA mortar test block [16,17] and on-site full scale push slab [18] are conducted to get the interface parameters. The research of structural instability focuses on buckling stability of uniform track slab.…”