The influence of slope geometric parameters on the reliability of slope reinforced by micro-piles in spatially variable soils

Currently, the combined effects of soil spatial variability and slope geometric parameters on the reliability of micro-pile reinforced slopes remain unclear. To evaluate the influence of slope geometric parameters on the reliability of micro-pile reinforced slope, a reliability calculation program considering the spatial variability of soil strength parameters was proposed in this study. By combining the effective micro-pile side pressure formula with the simplified Bishop method, the limit equilibrium calculation method for micro-pile reinforced slope was obtained. The Karhunen–Loève (K-L) expansion method was employed to generate random fields. The failure probability and reliability index of the slope were calculated by Monte Carlo Simulation (MCS). The effects of different reinforcement parameters and random parameters on the mean safety factor and reliability of micro-pile reinforced slope were studied, and the influence of slope geometric parameters on the reliability of micro-pile reinforced slope was analyzed. The results indicate that the stability of the slope is effectively improved by micro-pile reinforcement. After reinforcement, the reliability index is less affected by the change of slope geometric parameters. Compared to reducing the slope height, decreasing the slope ratio can more effectively ensure the enhancement of the slope's reliability. The reinforcement efficiency is the highest when the micro-pile is set near the foot of the slope. With the increase of slope ratio, the influence of the change of pile length on the reliability index increases. The influence of each random parameter on the reliability of the slope is different, and the influence of L_v is more significant. The influence of random parameters on the reliability index and safety factor of micro-pile reinforced slopes is essentially consistent across different geometric parameters.