To characterize the failure mechanism of anti-slide micropiles and the failure mode of slope

three sets of large-scale physical model tests were carried out on the soil slopes reinforced by anti-slide micropiles in a single row and three rows. The displacements and the strain of piles during the loading process were measured and the failure pattern through excavating was observed. It is found that the triple-row micropiles behave better in anti-sliding

whose capacity is 51.5% higher than that of the single-row piles

and the sliding body can deform significantly before it completely collapses or fails

implying that the triple-row micropiles are suited to be used for the expedient treatment. Secondary sliding surface which is arch-shaped can be generated in front area of the piles and links to main sliding surface preset; for the three-row piles

pumping area between pile and soil would appear in front of the third row and longitudinal cracks come into being in the slope surface. The pile deformation displays S-shaped. The bending deformation of piles leads to tension-compression and shear failure instead of the fracture failure as at the sliding surface of rock slope. The maximum of bending moment of the pile is located above the sliding surface. For the triple-row micropiles

the bending moment of the first row piles is the largest

then the third row and that of the second row is smallest.