Study of Material Composition Effects on the Mechanical Properties of Soil-Rock Mixtures

Abstract EN

Soil-rock mixtures are often seen in geological deposits.

Mechanical properties of these mixtures are controlled by microstructural characteristics such as rock size distribution, rock shape, locations, and content.

The effects of material composition on soil-rock mechanical properties were studied in the laboratory.

The soil-rock material was screened into different size categories.

Medium-scale shearing and triaxial experiments were used to study the relationships among macrodeformation, strength, content, size, and random location of rocks.

The medium-scale triaxial shearing instrument included the computer control system, EDC control system, and sensor response.

The stress-strain curve of soil-rock mixtures was found as a hardening curve which is approximately hyperbolic, and there was no obvious peak intensity value.

When the Mohr–Coulomb criterion was used to depict the curve under a shear strain of 0.15, cohesion first increased and then decreased, a finding opposite to the internal friction angle with a decrease in particle size.

Elastic modulus increased with an increase in rock size, but Poisson’s ratio remained constant.

In similar conditions, the random location of rocks can lead to a variation range of 4 degree of the internal friction angle, and cohesion values can change in a large range than the mean value.