Research on Similar Materials for Physical Model Tests of Rock Slopes

In the selection and manufacture of similar materials for physical model tests of rock slopes, only the similarities in the magnitudes of density, cohesion, internal friction angle and elastic modulus were generally taken into consideration. The ability of the obtained similar materials to reproduce the strength and deformation behaviors of rock masses under complicated stress conditions was typically not considered. First, limestone and sandstone were herein selected as sedimentary rock prototypes, according to the stratigraphy of Wenchuan earthquake-induced landslides. After the primary control indexes and manufacturing process were determined, two common configuration methods for similar materials in geological models were used to manufacture the standard samples for triaxial compression tests. Finally, static triaxial compression tests of the standard samples were conducted to study the stress-strain behaviors and failure modes of two similar materials under various confining pressures. The experimental results indicated that, before the shear failure of standard samples, the stress-strain curves of two similar materials were observed to have a linear elastic relationship under the different confining pressures, and were in accordance with those of the actual rocks. When shear failure of standard samples occurred under different ratios of confining pressure to uniaxial compression strength, the ratios of the deviatoric stresses acting on the samples to the corresponding uniaxial compression strengths were close to those of the actual rocks, whereas the failure strains of similar materials were less than those of the actual rocks.