1,721,049 research outputs found
FEM Modelling of Thin Weak Layers in Slope Stability Analysis
No full textModelling the presence and the effect of a thin weak layer of soil or rock in a slope stability analysis performed through the finite element method (FEM) presents several problems of purely numerical nature. This paper deals with a parametric analysis of three different 2D numerical case studies (both ideal and real) of unstable or potentially unstable slopes containing a thin soft band (or weak layer). The FEM software used is RS2 (Rocscience®). The aim is investigating the influence of some geometrical and numerical characteristics of the soft bands in the stability analyses. The Mohr–Coulomb elastic-perfectly plastic constitutive model for all the involved materials was assumed, and the mechanical parameters were kept constant. Instead, other fundamental parameters of the weak layer, such as the type of mesh elements, the mesh density, and the geometry, in terms of both thickness and outcrop shape, were changed, and results in terms of the critical Strength Reduction Factor (SRF) were compared. The main outcomes of this study represent practical suggestions on some numerical and technical aspects to users of FEM slope stability analyses, in order to obtain a precautionary assessment of slope stability
Micropiles made of reinforced polyurethane resins: load tests and evaluation of the bearing capacity
No full textExperimental analysis and modelling of shallow landslides
No full textThe paper presents the results of some experimental tests reproducing the triggering mechanism of a special kind of shallow landslides induced by rainfalls (soil slip) in a physical 1g model. The experimental data have been employed to verify the capability of a simplified stability model to describe the phenomenon and to back analyse its occurrence in a case history (Pizzo d’Alvano, Campania Region, 1998)
The method enables a direct correlation between the safety factor of a slope and rainfall intensity, as well as antecedent rainfall
Behaviour of reinforced polyurethane resin micropiles
No full textThis paper deals with the field behaviour, under tension and compression, of an innovative kind of micropile made from reinforced expanded polyurethane resin. Micropiles were installed in various sample sites characterised by the presence of silty-clayey soils. In order to analyse the frictional resistance of a single micropile and to determine the bearing capacity in different conditions, a series of field load tests was carried out. The method of construction of the micropiles and the execution of field tests are briefly described. On the basis of the field tests, a method to evaluate the ultimate load was defined. Moreover, the micropile-soil mechanical interaction was modelled by applying a simplified analytical solution of the load-displacement behaviour. The obtained results provide a useful support in the evaluation of both the serviceability and the ultimate design capacity of the investigated micropiles. The most innovative aspect of this technology lies in using less costly equipment than required for other pile types, with machines of reduced dimension, which can be very useful for underpinning works in restricted spaces under existing buildings
Modelling Rainfall-induced Shallow Landslides at Different Scales Using SLIP - Part I
No full textAbstractSLIP (Shallow Landslides Instability Prediction) is a mathematical model developed to foresee the triggering of rainfall-induced shallow landslides (soil slips) and the unstable condition of slopes affected by these phenomena. This physically-based model gives the factor of safety in function of the principal variables influencing the trigger of soil slips: rainfall, geometry, soil state, mechanical and hydraulic characteristics of soil. The specific characteristics of SLIP allowed to use the same means to model the phenomenon from the scale of the representative elementary volume (i.e. flume laboratory tests) to the medium and large scale (regional and national level). This paper (Part I), that is companion of another one published in this Conference (Part II), contains a brief description of the model and focuses on the approach followed in the application of the SLIP model at laboratory scale
Modellazione dell'innesco di alcuni movimenti franosi superficiali indotti da piogge nell'Appennino Parmense
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Sviluppo di un sistema di monitoraggio real-time per fenomeni franosi superficiali indotti da piogge
No full textX-Slip: un modello per l'innesco di frane indotte da piogge, fisicamente basato, implementato su piattaforma Experience
No full textI movimenti franosi superficiali indotti da pioggia: modellazione dell’innesco di eventi nell’Appennino Modenese
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