Analysis of liquefaction risk of sterile material in the inner dump of North Pesteana quarry in the conditions of flooding of the remaining gap

In the conditions of the dump slopes formed by loose rocks, predominantly sandy rocks, which are at the first saturation, there is a significant risk of sliding due to liquefaction of the waste material. The liquefaction process may be triggered by hydrological, mechanical or seismic factors. In saturated sand, the space between the solid granules is completely filled with water, and the pore water pressure, which increases as the depth increases, causes the grains to move away from each other, so the material is flowing. Among the methods for assessing the liquefaction potential of rock masses/deposits can be summarized: historical phenomena observations, studying the liquefying potential area maps, analysis of geological process that led to the creation of rock deposits and the nature of rocks. The paper aims at assessing the risk of liquefaction of sterile material in the inner dump of the North Pesteana quarry during the flooding of the remaining gap, since the preliminary studies found that the sterile material consists of important fractions of sand, indicating that there is liquefaction potential. The risk of liquefaction was determined taking into account the liquefaction potential, the nature of the objectives in the area and the probability of liquefaction.

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A Practical Saturated Sand Elastic-Plastic Dynamic Constitutive Model and Application

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.446-449.1621 ◽

2012 ◽

Vol 446-449 ◽

pp. 1621-1626 ◽

Cited By ~ 2

Author(s):

Yan Mei Zhang ◽

Dong Hua Ruan

Keyword(s):

Constitutive Model ◽

Pore Water ◽

Pore Water Pressure ◽

Water Pressure ◽

Stone Columns ◽

Saturated Sand ◽

Multidimensional Model ◽

Excess Pore Water Pressure ◽

Elastic Plastic ◽

Excess Pore

A practical saturated sand elastic-plastic dynamic constitutive model was developed on the base of Handin-Drnevich class nonlinear lag model and multidimensional model. In this model, during the calculation of loading before soil reaches yielding, unloading and inverse loading, corrected Handin-Drnevich equivalent nonlinear model was adopted; after soil yielding, based on the idea of multidimensional model, the composite hardening law which combines isotropy hardening and follow-up hardening, corrected Mohr-Coulomb yielding criterion and correlation flow principle were adopted. A fully coupled three dimension effective stress dynamic analysis procedure was developed on the base of this model. The seismic response of liquefaction foundation reinforced by stone columns was analyzed by the developed procedure. The research shows that with the diameter of stone columns increasing, the excess pore water pressure in soil between piles decreases; with the spacing of columns increasing, the excess pore water pressure increases. The influence of both is major in middle and lower level of composite foundation.

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Prediction of liquefaction potential and pore water pressure beneath machine foundations

Open Engineering ◽

10.2478/s13531-013-0165-y ◽

2014 ◽

Vol 4 (3) ◽

Cited By ~ 3

Author(s):

Mohammed Fattah ◽

Mohammed Al-Neami ◽

Nora Jajjawi

Keyword(s):

Pore Water ◽

Sandy Soil ◽

Pore Water Pressure ◽

Water Pressure ◽

Soil Liquefaction ◽

Elastic Model ◽

Liquefaction Resistance ◽

Overburden Pressure ◽

Liquefaction Potential ◽

Frequency Changes

AbstractThe present research is concerned with predicting liquefaction potential and pore water pressure under the dynamic loading on fully saturated sandy soil using the finite element method by QUAKE/W computer program. As a case study, machine foundations on fully saturated sandy soil in different cases of soil densification (loose, medium and dense sand) are analyzed. Harmonic loading is used in a parametric study to investigate the effect of several parameters including: the amplitude frequency of the dynamic load. The equivalent linear elastic model is adopted to model the soil behaviour and eight node isoparametric elements are used to model the soil. Emphasis was made on zones at which liquefaction takes place, the pore water pressure and vertical displacements develop during liquefaction. The results showed that liquefaction and deformation develop fast with the increase of loading amplitude and frequency. Liquefaction zones increase with the increase of load frequency and amplitude. Tracing the propagation of liquefaction zones, one can notice that, liquefaction occurs first near the loading end and then develops faraway. The soil overburden pressure affects the soil liquefaction resistance at large depths. The liquefaction resistance and time for initial liquefaction increase with increasing depths. When the frequency changes from 5 to 10 rad/sec. (approximately from static to dynamic), the response in displacement and pore water pressure is very pronounced. This can be attributed to inertia effects. Further increase of frequency leads to smaller effect on displacement and pore water pressure. When the frequency is low; 5, 10 and 25 rad/sec., the oscillation of the displacement ends within the period of load application 60 sec., while when ω = 50 rad/sec., oscillation continues after this period.

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Investigation about the Vibrational Compaction Work of Saturated Sand Layers with Elimination of Excess Pore-Water Pressure.

Doboku Gakkai Ronbunshu ◽

10.2208/jscej.1994.505_105 ◽

1994 ◽

pp. 105-114

Author(s):

Takeshi Ishiguro ◽

Takeshi Iijima ◽

Hideki Shimizu ◽

Saburo Shimada

Keyword(s):

Pore Water ◽

Pore Water Pressure ◽

Water Pressure ◽

Saturated Sand ◽

Excess Pore Water Pressure ◽

Excess Pore

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Analysis of shallow failures triggered by the 14-16 November 2002 event in the Albaredo valley, Valtellina (Northern Italy)

Advances in Geosciences ◽

10.5194/adgeo-2-305-2005 ◽

2005 ◽

Vol 2 ◽

pp. 305-308 ◽

Cited By ~ 15

Author(s):

S. Dapporto ◽

P. Aleotti ◽

N. Casagli ◽

G. Polloni

Keyword(s):

Pore Water ◽

Slope Failure ◽

Pore Water Pressure ◽

Limit Equilibrium ◽

Water Pressure ◽

Coupled Analysis ◽

Element Analysis ◽

Seepage Analysis ◽

The North ◽

Pressure Distributions

Abstract. On 14-16 November 2002 the North Italy was affected by an intense rainfall event: in the Albaredo valley (Valtellina) more than 200 mm of rain fell triggering about 50 shallow landslides, mainly soil slips and soil slip-debris flows. Landslides occurred above the critical rainfall thresholds computed by Cancelli and Nova (1985) and Ceriani et al. (1994) for the Italian Central Alps: in fact the cumulative precipitation at the soil slips initiation time was 230 mm (in two days) with a peak intensity of 15 mm/h. A coupled analysis of seepage and instability mechanisms is performed in order to evaluate the potential for slope failure during the event. Changes in positive and negative pore water pressures during the event are modelled by a finite element analysis of water flow in transient conditions, using as boundary condition for the nodes along the slope surface the recorded rainfall rate. The slope stability analysis is conducted applying the limit equilibrium method, using pore water pressure distributions obtained in the different time steps by the seepage analysis as input data for the calculation of the factor of safety.

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