Effect of Particle Morphology on the Monotonic Response of Gravel-Sized Soils through Large-Scale Simple Shear Testing

Abstract

Three gravel-sized materials are tested monotonically using a 305 mm diameter Cyclic Simple Shear (CSS) device and then visually characterized using a Translucent Segregation Table (TST) allowing for an assessment of the impact of particle size and morphology on the shear response of the materials. Three materials are tested to provide a range of particle morphologies and gradations: Pea Gravel, 6AA Limestone, and 5/8"-3/8" Natural Stone. Specimens were prepared in the CSS in loose and dense states. Tests in the CSS device included one dimensional compression and monotonic shearing. The TST is a custom-made device that rapidly determines the particle size and shape distribution of large specimens of coarse sands and gravels from a digital photograph. The device is designed to segregate the particles by size so that no grains are obstructed from camera view. It enables the characterization of the size and shape of every particle. The results from the TST characterization of the grain size distribution and morphology are related to the shear response of the gravel materials from the CSS device.

Evaluation of rock size on the mechanical behavior and deformation performance of soil-rock mixture: a meso-scale numerical and theoretical study

“…Raymond and Diyaljee (1979) also obtained the same test result. Through conducting direct shear tests on mixture of sand (0-2 mm) and gravel (2-6 mm, 2-20 mm), Simoni and Houlsby (2006) and Hubler et al (2014) noticed that material with larger grains showed a higher value of constant volume friction angle. For parameters such as internal friction angle, mobilized internal friction angle, and elastic moduli, similar conclusions were also presented by other researchers (Sitharam and Nimbkar 2000;Ahad and Mirghasemi 2009;Meng et al 2018;Alhani et al 2020).…”