Abstract: Anti-slide pile is a major engineering measure to reinforce debris landslide. The interaction between anti-slide pile and sliding mass determines the reinforcement effect. Debris landslide is mostly composed of soil-rock mixture. A model for evaluating the macro-shear strength index of soil-rock mixture is introduced to calculate the sliding resistance of anti-slide pile in soil-rock mixture. A method of calculating sliding resistance in consideration of volumetric block proportion (VBP) and angle of repose (δ) is presented based on the theory of soil arch between piles. The design procedures of anti-sliding pile in soil-rock mixture are also proposed. According to the study of soil-rock mixture with a VBP of 20%~45% and δ of 25°~40°, the sliding resistance provided by anti-slide pile in soil-rock mixture is not always greater than that in soil. The safety of anti-slide pile depends on the value of VBP and δ, with a clear dividing line. Comparison with numerical simulation results verifies the rationality of the present method.

Key words: anti-slide pile, soil-rock mixture, debris landslide, sliding resistance, volumetric block proportion, angle of repose