Assessment of the Impact of Inundation on the Strength of a Lateritic and Collapsible Soil

Falcão, P; Baroni, Magnos; Masutti, Gustavo Corbellini; Pinheiro, Rinaldo José Barbosa; Fagundes, Diego de Freitas

doi:10.1007/s10706-023-02545-y

Cited by 4 publications

(2 citation statements)

References 24 publications

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“…Instead, at residual conditions, both samples are characterized by nil effective cohesion, and the residual shear strength angle is equal to 28° for both soils (Figure 16). The results appear consistent with those obtained by other authors on similar materials [42][43][44].…”

Section: Direct Shear Testssupporting

confidence: 93%

“…The failure conditions of soils have been obtained by performing consolidated drained (CD) direct shear tests on the AR1 and AR2 samples based on British Standards [41]. The same laboratory tests have been recently performed by other researchers on lateritic soils from different geographical areas [42][43][44]. Direct shear tests were performed on saturated specimens, whose size was 60 mm × 60 mm × 30 mm, at a shear velocity of 0.01 mm/min.…”

Section: Mechanical Characterizationmentioning

confidence: 99%

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Combined Effect of the Microstructure and Mechanical Behavior of Lateritic Soils in the Instability of a Road Cut Slope in Rwanda

Valentino,

Pizzati,

Mizero

2024

GeoHazards

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A very common hazard in Rwanda is represented by the instability of steep road cut slopes in lateritic soil. In its natural state, this material appears as a fine-grained weak and altered rock, generally in unsaturated conditions. Steep cut slopes made by this material could remain stable for a long time unless weathering weakens its mechanical behavior and heavy rainfall provokes a rapid landslide. This paper presents the results of an experimental investigation on the microstructural, petrophysical, and geotechnical properties of lateritic soil from a road cut slope located in Kabaya (Ngororero District—Rwanda), which was recently subjected to a landslide. The mechanical properties of the material are strictly related to the geological origin and history of the deposits, their formation environment, and weathering processes. These characteristics were revealed by peculiar microstructural features (micro-texture, porosity, and degree of alteration of original mineral paragenesis). The experimental investigations included identification and classification tests, direct shear tests on saturated samples, and swelling tests. This multidisciplinary approach provided insights into the relationship between geotechnical properties and the microstructural, petrophysical, and chemical characteristics of the altered rocks. This study showed how different levels of chemical alteration operated by weathering processes, in conjunction with brittle deformation related to the tectonic history, formed in the same site two shallow rock layers with similar macro-scale features and mechanical behaviors but markedly different microstructural and chemical properties. The innovative aspect of this research suggests an integrated multidisciplinary approach to considering microstructural aspects in addition to mechanical behavior in the slope stability analyses in lateritic soil. In particular, this study demonstrates the importance of such an approach since the failure mechanism is better explained if it is based on microstructural observations instead of considering the soil shear strength parameters only. This research helped to explain the formation of the landslide failure mechanism in a specific road cut slope, which could be assumed as representative of many other similar slopes subjected to landslides in Rwanda.

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Section: Direct Shear Testssupporting

confidence: 93%

Section: Mechanical Characterizationmentioning

confidence: 99%