CRTS III ballastless track, Geotextile isolation layer, Fatigue performance, Freeze-thaw cycle, Mechanical properties, Experimental research, Materials of engineering and construction. Mechanics of materials, TA401-492

To investigate the fatigue and freeze-thaw properties of the geotextile isolation layer in CRTS III ballastless track, a new type of disc multi-point load distribution device was manufactured. The experimental study was carried out on the geotextile isolation layer subjected to the fatigue load and freeze-thaw cycles. The results showed that the mechanical properties of the geotextile isolation layers were affected by the harsh environment and cyclic load. With the increase of fatigue loading cycles, the dynamic stiffness of the geotextile isolation layers increased and tended to be stable, and the nonlinear performance of the geotextile isolation layer gradually weakened. The freeze-thaw cycle greatly influenced the dynamic stiffness of the geotextile isolation layer compared with the fatigue loadings, and the freeze-thaw cycle action could accelerate the elastic loss of the geotextile isolation layer. Under the fatigue load and freeze-thaw cycles, the tensile strength of the geotextile isolation layer decreased and caused damage to the geotextile isolation layers, which should be paid attention to in long-term service.