Hydromechanical behaviour of a volcanic ash

Ferrari, Alessio; Eichenberger, John; Laloui, Lyesse

doi:10.1680/geot.13.p.041

Cited by 24 publications

(13 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Most of the fully coupled unsaturated numerical formulations that are based on the traditional FE method can only model the initial failure surface, and this would not be a good estimate when predicting landslide volume as it can be much larger during the post‐failure motion. Because of the high level of risk associated with landslides in steep terrains, these simulations use some of the most common features such as slope angle that lies between 35°and 45°, internal friction angle that lies between 35°and 39°, existing shallow soil covers above the bedrock that can result in a perched water table and very low‐lying regional water table . As mentioned earlier, this case study was inspired by the full‐scale field test performed in Rüdlingen, Switzerland , where a landslide of 130 m 3 volume was observed after 15 h of rainfall.…”

Section: Validation and Application Examplesmentioning

confidence: 99%

Modelling landslides in unsaturated slopes subjected to rainfall infiltration using material point method

Bandara

Ferrari

Laloui

2016

Num Anal Meth Geomechanics

124

View full text Add to dashboard Cite

SUMMARYThis paper presents a dynamic fully coupled formulation for saturated and unsaturated soils that undergo large deformations based on material point method. Governing equations are applied to porous material while considering it as a continuum in which the pores of the solid skeleton are filled with water and air. The accuracy of the developed method is tested with available experimental and numerical results. The developed method has been applied to investigate the failure and post-failure behaviour of rapid landslides in unsaturated slopes subjected to rainfall infiltration using two different bedrock geometries that lie below the top soil. The models show different failure and post-failure mechanisms depending on the bedrock geometry and highlight the negative effects of continuous rain infiltrations.

show abstract

Section: Validation and Application Examplesmentioning

confidence: 99%

Modelling landslides in unsaturated slopes subjected to rainfall infiltration using material point method

Bandara

Ferrari

Laloui

2016

Num Anal Meth Geomechanics

124

View full text Add to dashboard Cite

show abstract

“…On the other hand, for soils that contain a "shielding skeleton" of coarse particles it is possible to envisage that the shielding skeleton limits the shrinkage on drying of the bulk sample while the clayey fraction may continue to shrink and create macropores (Romero, 2013). It is well known that collapse can occur in silty soils, similar to the loess described by Muñoz-Castelblanco et al (2011) and the volcanic ash described by Ferrari et al (2013). This paper on the other hand is concerned with a high plasticity clay.…”

Section: Introductionmentioning

confidence: 98%

Microstructural changes of an undisturbed, reconstituted and compacted high plasticity clay subjected to wetting and drying

Burton

Pineda

Sheng

et al. 2015

Engineering Geology

116

View full text Add to dashboard Cite

a b s t r a c tThe behaviour of soil, and in particular compacted clay fill, can have significant implications on the safe and reliable operation of man-made infrastructure. The mechanical behaviour of soil (e.g. volume change and shear strength) is widely recognised as being associated with the microstructural arrangement (fabric/structure). In the case of high plasticity clays, despite the large amount of research carried out, soil microstructure and its evolution along mechanical and hydraulic paths are still not well understood. This makes incorporation of microstructural analysis difficult in engineering practice and highlights the need for further research. A comprehensive microstructural analysis of Maryland clay, a high plasticity residual soil, based on mercury intrusion porosimetry tests, is presented in this paper. Experimental results obtained from undisturbed, reconstituted and compacted specimens subjected to different hydraulic and mechanical paths are described. As with mechanical investigations, the reconstituted state is proposed to be used routinely as a reference state for comparison of undisturbed and compacted soil. The microstructural evolution of the compacted clay, prepared on the wet side of standard Proctor optimum water content, with an initially high void ratio, is examined along the main drying path. Importantly, a monotonic suction increase from the as-compacted state is shown to have negligible effect on the distribution of macro-pores. However, a new insight is provided based on the evolution of the dominant micro-pore entrance diameter which is shown to reduce with increased suction. This micro-pore entrance diameter is shown to correspond with the theoretical suction back-calculated from a simple capillary tube model, up to a limit. It is observed that, under oedometric conditions, the as-compacted microstructure is erased during saturation (soaking) and resembles the reconstituted microstructure. For this particular material and preparation conditions, it is demonstrated that a bimodal microstructure is not recovered on drying from a saturated state.

show abstract

“…namely ashy soil 'A' in previous experiments (Bilotta et al, 2005), which is generally found at the bedrock contact of shallow pyroclastic deposits. It is very loose soil (n = 0•645-0•651) with a metastable structure along steep slopes (Sorbino et al, 2011), similar to other volcanic soils (Ferrari et al, 2013). The grain size distribution consists in 43•6-51•9% sand, 43•9-54•03% silt and 1•4-4•7% clay.…”

Section: Investigated Soilmentioning

confidence: 79%

Wetting tests of partially saturated soils under simple shear conditions

Cuomo¹,

Moscariello²,

Foresta³

2017

Géotechnique Letters

View full text Add to dashboard Cite

The paper provides some remarks on a new suction-controlled simple shear apparatus. The features of the testing device are first outlined and the material used in the experimental programme is described. As a fundamental field of application, wetting tests under simple shear conditions are performed, being representative of the initial stress conditions and stress paths related to the typical triggering mechanisms of rainfall-induced shallow landslides. The benefits of this new device are illustrated, as an alternative or additional tool to other existing equipment. This paper presents a short selection of the measurements obtained using a partially saturated volcanic soil, which is prone to static liquefaction and volumetric behaviour on shearing. The challenges associated with simple shear tests are also discussed using a few examples from the ongoing work

show abstract

Hydromechanical behaviour of a volcanic ash

Cited by 24 publications

References 20 publications

Modelling landslides in unsaturated slopes subjected to rainfall infiltration using material point method

Modelling landslides in unsaturated slopes subjected to rainfall infiltration using material point method

Microstructural changes of an undisturbed, reconstituted and compacted high plasticity clay subjected to wetting and drying

Wetting tests of partially saturated soils under simple shear conditions

Contact Info

Product

Resources

About