Abstract:
Objective Accurate calculation of ultimate resistance is a core issue in the design of small-diameter composite anti-slide piles, but relevant studies remain limited.
Methods Based on the soil-arching effect behind piles, this study establishes an ultimate-resistance calculation model that comprehensively considers soil shear-strength parameters, pile arrangement, and resistance in front of the piles.
Results The model was validated using the Sanhepu landslide project in Wushan County, Chongqing. The results indicate that the proposed model is more consistent with the actual landslide conditions than existing models. An analysis of factors affecting ultimate resistance shows that ultimate resistance decreases with increasing pile spacing and increases with increasing soil cohesion, internal friction angle, pile diameter, and resistance in front of the piles.
Conclusions On this basis, the applicable conditions for small-diameter composite anti-slide piles are further clarified. They are suitable for soils with certain cohesion and internal friction angle and should be used cautiously in soft clay and sandy soils. A quincunx pile arrangement is preferred, with a combined strategy of small pile spacing and large pile diameter, while considering construction conditions, project cost, and the risk of blocking groundwater seepage channels. The piles should be arranged in the resisting section of the slope and combined with drainage measures. These findings provide a theoretical basis for the design and engineering application of small-diameter composite anti-slide piles.