Ingenieurwissenschaften und zugeordnete Tätigkeiten
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Erscheinungsjahr
- 2017 (2)
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- Englisch (2)
Referierte Publikation
- ja (2) (entfernen)
Schlagworte
- Aberfan flowslide (1)
- Landslide propagation modelling (1)
- Numerical modelling (1)
- Perzyna viscoplasticity (1)
- SPH (1)
- Soil-pile interaction (1)
The purpose of the work presented in this paper is to analyze locally (at the element level) the contact behavior of a soil-pile contact problem. Therefore, a 2D shear test is modeled using the Finite Element Method. The formulation of a 4 nodded zero-thickness interface element of Beer is chosen with a linear interpolation function. Four constitutive contact models adapted for contact problems have been implemented. The Mohr-Coulomb and Clough and Duncan models were chosen initially, due to the ease of implementation and few number of parameters needed. After, more complicated models in the framework of elasto-plasticity such as: Lashkari and Mortara were implemented for the first time into the finite element code of the shear test problem. They include other phenomena such as: relative density of soil, the stress level and sand dilatancy. From the results the relation between shear displacement and shear stress has been deduced. Finally, a discussion of the advantages and the drawbacks during computation of each model is given at the end.
The choice of a pure cohesive or a pure frictional viscoplastic model to represent the rheological behaviour of a flowslide is of paramount importance in order to obtain accurate results for real cases. The principal Goal of the present work is to clarify the influence of the type of viscous model—pure cohesive versus pure frictional—with the numerical reproduction of two different real flowslides that occurred in 1966: the Aberfan flowslide and the Gypsum tailings impoundment flowslide. In the present work, a depth-integrated model based on the v-pw Biot–Zienkiewicz formulation, enhanced with a diffusion-like equation to account for the pore pressure Evolution within the soil mass, is applied to both 1966 cases. For the Aberfan flowslide, a frictional viscous model based on Perzyna viscoplasticity is considered, while a pure cohesive viscous model (Bingham model) is considered for the case of the Gypsum flowslide. The numerical approach followed is the SPH method, which has been enriched by adding a 1D finite difference grid to each SPH node in order to improve the description of the pore water evolution in the propagating mixture. The results obtained by the performed simulations are in agreement with the documentation obtained through the UK National Archive (Aberfan flowslide) and the International Commission of large Dams (Gypsum flowslide).