Geosynthetic-reinforced soil wall behaviour under high-speed railway moving cyclic loads

With the rapid expansion of high-speed railway (HSR) infrastructure, ensuring the long-term stability of geosynthetic-reinforced soil (GRS) walls under repeated traffic loading is critical. This study investigates the dynamic mechanical behaviour of HSR GRS walls using a combination of physical model tests and three-dimensional dynamic numerical simulations. A moving vehicle loading device developed by the authors was employed to realistically simulate the driving effects of high-speed trains, addressing the limitations of traditional sinusoidal loading systems. Results indicate that wall crest settlement increases rapidly during the initial 500 cycles (contributing ∼50% of total settlement) before exhibiting a continued, albeit reduced, increasing trend. A characteristic ‘bulging’ deformation pattern was observed, with peak horizontal displacements occurring at approximately two-thirds of the wall height. Furthermore, vertical earth pressure exhibited a clear diffusion pattern, attenuating downward from the loading plate. The computed potential failure surface aligns closely with the 0.3H surface (where H is the wall height) specified in current design codes, providing a robust theoretical basis for the seismic and dynamic design of railway retaining structures.