Stability of Slopes Reinforced with Truncated Micro-pile

ABSTRACT Micro-piles are extensively used as a means of slope stabilisation. In this paper, slope reinforced with micro-pile under different conditions is considered. The influencing factors include the truncation length, diameter, location, the number of rows of micro-piles, and the existence of weak interlayers. A simplified numerical simulation was conducted to analyse the safety factor and failure modes of slopes under different conditions, and the impact of micro-pile truncation length on the reinforcement effect of various slopes was obtained. The results show that the truncation length has a relatively small impact on the reinforcement effect of homogeneous slopes. Due to the grouting during construction, the grout fills the gaps between the soil, causing the closely spaced micro-piles and the soil between the piles to form a solid continuum, jointly acting as an antisliding retaining wall. The shortened pile length means that the range of the pile-soil composite body is reduced, but it can still provide anti-sliding support. For slopes with weak interlayers, the reinforcement effect is significantly weakened as the truncation length increases. When a slope with weak interlayers slides, the shear strength of the micro-piles is the decisive factor for slope stability. The micro-piles are subjected to tensile-shear stress, and truncating the pile length decreases the anchoring force between the sliding mass and the micro-piles, resulting in a significant reduction in the reinforcement effect of the engineering.