Working performance and mechanism of a novel upper-hollow drainage anti-slide pile under the effect of reservoir water fluctuation and precipitation

Anti-slide piles have been widely applied in many practical projects around the world. In this work, a novel upper-hollow drainage anti-slide pile (UDAP) is selected to evaluate its working performance and mechanism by means of a physical model test and a numerical simulation. The physical model test indicates that UDAPs exhibit an excellent drainage performance, and the earth pressure and the pore water pressure around them dramatically decrease. The catchment holes placed on the lateral and upslope sides of the UDAPs have the same effects, and their drainage capacity improves with depth. The numerical simulation results of the UDAP arranged in the Quchi landslide (China) indicates that the retaining effect of the UDAPs is significantly better than that of the conventional anti-slide piles (CAPs). The landslide thrust and deformation are reduced due to the decrease of groundwater table and the consequent pore water pressure reduction due to the drainage effect of the UDAPs. Furthermore, the deflection and internal force of the UDAPs are significantly lower than those of the CAPs. The retaining effect of the continuous and interval arrangement scheme of the UDAPs is almost identical. Furthermore, the value of the internal force and the law of variation of the UDAPs and CAPs are basically the same. Therefore, the results of this paper can provide an important basis for the future research, design, popularization and application of the UDAPs.