Probabilistic stability analyses of slope reinforced with piles in spatially variable soils

Abstract

In this paper, deterministic stability analyses for soil slopes reinforced with pile of different locations and lengths were conducted firstly to calculate the factor of safety through limit equilibrium method (LEM). Since the effect of inherent uncertainties as well as the spatial variability of soils cannot be reflected via the deterministic factor of safety, probabilistic stability analyses of slopes reinforced with pile in spatially constant soils and spatially variable soils were successively carried out, respectively. The failure probability was determined by random limit equilibrium method (RLEM) considering the influence of different pile locations, pile length and soil statistical parameters. The optimal locations along slope and length of pile were analyzed based on the reliability analyses results in spatially constant soils and spatially variable soils, which were inconsistent with the results via the traditional deterministic methods, with a lower probability of sliding failure. Finally, method was proposed to determine the minimum samples of simulation iterations for investigating the convergence of failure probability of soil slope reinforced with piles. The results revealed that the multiple potential sliding surfaces introduced by the installations of pile would result in the increased uncertainty of slope failures.