Study on Particle Breakage and Strength Characteristic of Different Coarse-Grain Contents

Abstract

The significant particle size grading and the particle breakage of deep soils are two major characteristics of super-high dumping-site. Based on the refitted large-scale direct shear experiments, this paper studied the particle breakage and shear strength of different coarse-grained soil. The experimental results indicates a conclusion: particle breakage index is very small when upright stress is less than 400kPa .The breakage rate increases obviously with the increase of upright stress. The particle breakage index is very little when coarse-grained contents are less than 46.0% .It increases significantly when coarse-grained contents are larger than 46.0%. Hyperbolic curves can express the relationship between particle breakage index and upright stress. The experiments studied on shear strength shows that the shear stress-strain curves are micro-softening model or micro-hardening model under low upright stress. The curves are slight-softening model at higher upright stress when the coarse-grained contents are equal to 24.0%. At coarse-grained contents equal 78.0%, the shear stress-strain curves are softening model under low upright stress. The shear strength envelope expressed nonlinear under higher upright stress.