Microstructural observations of shear zones at cohesive soil-steel interfaces under large shear displacements
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Date
2021-04-27
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Abstract
Failure mechanism which can affect geotechnical infrastructures (shallow foundations, retaining walls, and piles)
constitutes one of the most encountered problems during the design process. In this respect, the shear behavior of interfaces
between grained soils and solid building materials, as well as those between cohesive soils should be investigated. Therefore, a
range of ring shear tests with different cohesive soils and stainless-steel interfaces have been carried out through the Bromhead
apparatus that allows simulating large displacements along a failure surface. The effects of steel rings roughness and soil type on
the residual friction coefficient and the shear zone features (structure, thickness, and texture orientation angle) have been
investigated using the Scanning Electron Microscopy. The obtained results indicate that the residual friction coefficient and the
structural characteristics of the shear zone vary according to the surface roughness and the soil type. Scanning electron
microscopy reveals that the particles inside the shear zone tend to be re-oriented. Also, the shear failure mechanism can be
identified along with the interface, within the soil, or simultaneously at the interface and within the soil specimen.