Predictive equation of shear-strength parameters and permeability of grus using by unit weight and grain size

Abstract

Based on the results of field measurement of physical and mechanical properties of hillslope materials in granitic mountains, the angle of shearing resistance (φsat, degree), the cohesion (C_sat, gf/cm²) and the hydraulic conductivity (K, cm/sec) of grus under saturated water content were deduced by two parameters of unit weight and grain size of soil as following regression equations :
φ_sat=22.2γ_dCC_0.0625+9.5(R²=0.71)
C_sat=133.6γ_d-55.7CC_2.0-100.0(R²=0.75)
log₁₀K=-1.512γ_dCC_2.0^-0.211(R₂=0.79)
where γ_d is the dry unit weight of soils (gf/cm³) and CC_D is the content for coarser grains than D mm. Since the values of CC_0.0625 and CC_2.0 can be easily measured by sieving method and γ_d is estimated using simplified dynamic cone penetrometer, these parameters can be estimated using the above equations at many points and depths of the soil layer on steep mountains.