Shaking table test for reinforcement of soil slope with multiple sliding surfaces by reinforced double-row anti-slide piles

Despite the continuous advancements of engineering construction in high-intensity areas, many engineering landslides are still manufactured with huge thrust force, and double-row piles are effective to control such large landslides. In this study, large shaking table test were performed to test and obtain multi-attribute seismic data such as feature image, acceleration, and dynamic soil pressure. Through the feature image processing analysis, the deformation characteristics for the slope reinforced by double-row piles were revealed. By analyzing the acceleration and the dynamic soil pressure time domain, the spatial dynamic response characteristics were revealed. Using Fast Fourier Transform and half-power bandwidth, the damping ratio of acceleration and dynamic soil pressure was obtained. Following that, the Seism Signal was used to calculate the spectral displacement of the accelerations to obtain the regional differences of spectral displacement. The results showed that the overall deformation mechanism of the slope originates from tension failure in the soil mass. The platform at the back of the slope was caused by seismic subsidence, and the peak acceleration ratio was positively correlated with the relative pile heights. The dynamic soil pressure of the front row piles showed an inverted “K”-shaped distribution, but that of the back row piles showed an “S”-shaped distribution. The predominant frequency of acceleration was 2.16 Hz, and the main frequency band was 0.7–6.87 Hz; for dynamic soil pressure, the two parameters became 1.15 Hz and 0.5–6.59 Hz, respectively. In conclusion, dynamic soil pressure was more sensitive to dampening effects than acceleration. Besides, compared to acceleration, dynamic soil pressure exhibited larger loss factors and lower resonance peaks. Finally, back row pile heads were highly sensitive to spectral displacement compared to front row pile heads. These findings may be of reference value for future seismic designs of double-row piles.