Considering the engineering background of the dangerous western mountain railroad

large-scale shaking table model experiments were conducted on embankment slopes supported by single and double-row piles

subjected to El-Centro wave excitations. Based on parameters such as displacement and acceleration

an in-depth investigation was conducted to study the differences in dynamic response characteristics between the two slope models. Moreover

the reasons for the differences between the two slopes were explored using fast Fourier transform (FFT) spectra. The results revealed that both the support effect and the differences in anti-slip piles gradually increased with the increase in the input wave amplitude. At input wave amplitudes of 0.1g−0.3g

both single and double-row pile slopes remained stable

with minimal differences in their overall dynamic response characteristics. However

at an input wave amplitude of 0.4g

significant differences in the dynamic responses of both slopes emerged. Macroscopic damage was more apparent in the single-row pile slope

with high slope surface displacement

accumulated soil damage

and noticeable nonlinear characteristics. At an input wave amplitude of 0.5g−0.6g

both slope models exhibited a pronounced “elevation effect” in the peak ground acceleration (PGA) amplification factor. Additionally

plastic zones were observed on the road cut face and behind the piles in both models. The presence of retaining piles effectively suppressed the upward trend of PGA amplification coefficients along the slope and prevented the connection of plastic zones on the slope surface. Notably

the PGA amplification effect of the single-row pile slope was pronounced

with a wide and deep plastic zone

severe local instability

and relatively weak seismic support effect. The introduction of the FFT spectral ratio revealed that the difference in amplitude amplification effects of single and double-row pile slopes in the 5−10 Hz band was the main reason for the difference in their dynamic responses. Under seismic loading

the failure process of the single-row pile-supported slope involved three stages: initial stability of the slope

plastic deformation of the slope surface soil

and local collapse and disintegration of the slope. In contrast

the double-row pile-supported slope experienced the first two stages of this failure process.