STUDY ON THE RELATIONSHIP BETWEEN ENERGY EVOLUTION AND STRENGTH PARAMETERS OF COARSE-GRAINED SOILS IN DIRECT SHEAR TEST

In order to explore the relationship between the energy evolution and the strength parameters of coarse-grained soils during shearing, a direct-shear test was conducted to analyze the energy evolution process and strength characteristics of coarse-grained soils. According to the principle of conservation of energy, the Mohr-Coulomb strength criterion was used to derive the balance equation between energy and strength parameters. A theoretical model and an applicable model were established, demonstrated and analyzed, to explore the quantitative correlation between energy and strength parameters of coarse-grained soils. Combined with MATLAB analysis function, the application of the models was discussed. The results have shown that: due to the intense energy evolution process of angular particles, the strength parameters of angular contact particles were larger than that of circular particles, with greater energy of the work done by external force to reach the critical peak stress; under different normal stresses, at the final phase, the work done by external force—F(c, φ) was linearly dependent on strength parameter values, and increased with the increase of the strength parameter values. Furthermore, its partial differential equation converged infinitely to the fixed value—f(c_α, φ_β). The research results can be used to analyze the shearing condition and energy evolution process of the roadbed filler, and to invert the strength parameter values that meet the engineering needs.