Abstract: Soil-rock mixture is usually the main material for reservoir slope, landslide and dam foundation. The physical and mechanical properties of soil-rock mixtureare more complicated than common soil mass or rock mass, which is a difficult problem for researchers in the fields of rock mechanics, soil mechanics and geological engineering. In order to study the effect of gravel on uniaxial compressive strength and the mode of deformation failure of soil-rock mixture, we carried out unconfined uniaxial compression test by making mixture with certain rock block proportion. Combined with numerical method, the effect of spatial distribution of gravel on mixture’s overall strength was analyzed. The results show that, rock block proportion and spatial distribution of gravel have significant impact on uniaxial compressive strength and characteristics of deformation failure in soil-rock mixture. Uniaxial compressive strength declines with the increase of rock block proportion, at the same time, failure mode changes from single-crack failure to multi-crack failure, and time of propagation and coalescence of cracks increases.

Key words: soil-rock mixture, gravel content, gravel distribution, failure mode, uniaxial compressive strength