Pile reinforcement behavior and mechanism in a soil slope under drawdown conditions

Abstract

Piles are an effective measure for landslide protection under various loading conditions. However, the pile reinforcement mechanism of slopes has not been systematically investigated in previous studies under drawdown conditions. A series of centrifuge model tests were conducted on slopes with various pile reinforcement layouts under drawdown conditions to study the progressive slope failure process and slope failure mechanism. Compared with the unreinforced slope, the pile-reinforced slope had a greater safety limit and underwent less deformation. The failures of the unreinforced slope and pile-reinforced slope were both progressive from the top to the bottom of the slope under drawdown conditions with the same mechanism and could be described in terms of the significant coupling between the deformation localization and local failure. The pile reinforcement mechanism was clarified because the piles delayed the occurrence of deformation localization and decreased the localization degree of the slope under drawdown conditions. The reinforcement effect of piles includes two aspects: the compression enhancing effect and shear reducing effect. The compression enhancing effect was dominant near the piles and gradually decreased with increasing distance from the piles, and the shear reducing effect was dominant near the potential slip surface.