Abstract
Stone dust, a by-product of metal aggregate quarries, is utilized successfully as an alternative material for sand in concrete, as road material, and in bearing-capacity problems. An attempt has been made in this study to utilize stone dust as backfill material. A series of tests were performed on laboratory models of reinforced stone dust walls under strip loading. Manually prepared grids of natural material bamboo and commercially available steel grids were used as reinforcement. Bamboo grids and steel grids were used as strips, concrete segmental blocks were used as facia, and the behavior of walls was studied under strip loading by varying lengths of reinforcement and vertical spacing between the reinforcement layers. Bamboo grids in strip form are good enough to resist high failure surcharge pressures, and the results are comparable with the steel grid–reinforced stone dust walls. Geofoam blocks having a density of 0.12 kN/m3and thicknesses of 5 mm, 15 mm, and 20 mm were placed behind the segmental concrete facia blocks to study their effect on lateral displacement of facia and surcharge at failure. The results show a good trend in reducing the facia displacements and increasing the surcharge at failure as the thickness of the geofoam blocks placed behind each facia unit is increased. Finite-element simulation of the model tests was carried out using commercially available Plaxis 2D software. Stone dust was modeled as linear elastic perfectly plastic material with Mohr–Coulomb failure criteria, and bamboo and steel grids were modeled as elastic material. The finite-element simulation results for failure patterns, horizontal displacement of facia, and settlement of the backfill showed reasonable agreement with the experimental results.