Impact of transient seepage on slope stability of earth-rock dams with geomembrane barrier defects

2020 ◽  
Vol 7 (8) ◽  
pp. 581-590
Author(s):  
Weijun Cen ◽  
Dengjun Li ◽  
Hui Wang
Keyword(s):  
Slope Stability ◽  
Transient Seepage

scholarly journals Vector Sum Analysis Method of Loess Slope Stability under Rising Groundwater Level Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Haibin Xue ◽  
Faning Dang ◽  
Yanlong Li ◽  
Xiaotao Yin ◽  
Man Lei
Keyword(s):  
Spatial Distribution ◽  
Slope Stability ◽  
Groundwater Level ◽  
Analysis Method ◽  
Seepage Analysis ◽  
Force Method ◽  
Loess Slope ◽  
Structural Deterioration ◽  
Transient Seepage ◽  
Vector Sum

The stability analysis of loess slopes with a rising groundwater level is a problem that integrates unsaturated and transient seepage, stress analysis, and stability prediction. For this purpose, a sequentially coupled method of seepage-softening-stability was used. First, seepage analysis of a loess slope with a rising groundwater level was conducted according to unsaturated and transient seepage analysis theory. Second, the spatial distribution of the deformation and strength parameters of the soil, both of which were based on the calculated results of the seepage analysis, were adjusted according to the water-induced structural deterioration equation. Third, the vector sum analysis method of loess slope stability, which was based on the temporal-spatial distribution laws of effective unit weight, elastic modulus, Poisson’s ratio, cohesion, internal friction angle, and seepage force, was performed by the body force method. To verify the proposed method, the limit equilibrium method of loess slope stability was conducted by the surface force method. Finally, the progressive failure process of a loess slope with a rising groundwater level on the White Deer Plain was presented as an example. A comparison analysis of the calculated results of the two methods revealed that the proposed method was reasonable and reliable.

The importance of accounting vegetation on unsaturated slopes prone to rainfall-induced instabilities – a case study in Norway

2021 ◽  
Author(s):  
Luca Piciullo ◽  
Vittoria Capobianco ◽  
Håkon Heyerdahl
Keyword(s):  
Slope Stability ◽  
Pore Water Pressure ◽  
Initial Conditions ◽  
Water Pressure ◽  
Railway Track ◽  
Climate Conditions ◽  
Birch Trees ◽  
Transient Seepage ◽  
Pressure Regime ◽  
Steep Slopes

<p>In unsaturated steep slopes, the upper unsaturated zone may have a crucial role in the slope stability. In this work we studied a natural slope located adjacent to a railway track in Eastern Norway. Due to its steep inclination, the factor of safety should be always kept under observation. In addition, the climate in Norway is expected to become wetter and warmer, with increased snow melting. Thus the rainfall/snowmelt infiltration play an important role and needs to be monitored properly to avoid any failure. The slope is instrumented since 2016 and both volumetric water content (VWC) and the pore water pressure regime are monitored.</p><p>The modulus SEEP/W of the commercial software GeoStudio (GEO-SLOPE International, Ltd.) was used to model the transient seepage conditions of the slope for a 7-month monitoring period (from June 2019 to December 2019). Several analyses were carried out by changing the initial conditions and the boundary climate conditions of the slope. Regarding the initial conditions, two series of simulations were carried out, one with an initial calibration of the VWC distribution, another one without calibration, hence, by only locating the ground water table at a specific depth and by indicating the maximum negative head (as required by the model). The calibration, instead, consisted in starting the simulation considering a VWC distribution as closer as possible to the in-situ value.</p><p>For each series, a total of three simulations were carried out with different boundary climate conditions, respectively considering only rainfall/snowmelt (R), considering both rainfall/snowmelt and evaporation (Cl), and considering rainfall/snowmelt and evapotranspiration due to vegetation (V). Indeed, the slope is all covered by relatively dense vegetation, with shrubs and birch trees. For the simulations including evaporation and vegetation (Cl and V), the land-climate interaction boundary condition was adopted. Climate functions, such as the pairs temperature-time, relative humidity-time, wind speed-time, were obtained from a close meteorological station. The evaporation was determined by using the Penman-Monteith equation, including vegetation features in the case of vegetated slope. Preliminary results show that the initial calibration is important for the correct back-analyses of the measured data, and that the model is more accurate when accounting for climate boundary conditions and vegetation, which influence also the slope stability conditions.</p><div>The work has been part of the working package "Landslide triggered by hydro-meteorological processes" within the Center for Research-based Innovation (CRI) programme KLIMA2050 (), financed by the Research Council of Norway.</div>

scholarly journals Influences of root-induced soil suction and root geometry on slope stability: a centrifuge study

2017 ◽  
Vol 54 (3) ◽  
pp. 291-303 ◽  
Author(s):  
A.K. Leung ◽  
V. Kamchoom ◽  
C.W.W. Ng
Keyword(s):  
Slope Stability ◽  
Soil Suction ◽  
Intense Rainfall ◽  
Centrifuge Modelling ◽  
Clayey Sand ◽  
Mechanical Reinforcement ◽  
Root Reinforcement ◽  
Real Roots ◽  
Soil Bioengineering ◽  
Transient Seepage

Soil bioengineering using vegetation has been recognised as an environmentally friendly solution for shallow slope stabilization. Plant transpiration induces suction in the soil, but its effects on slope stability are often ignored. This study investigates the influences of transpiration-induced suction and mechanical reinforcement of different root geometries (i.e., tap- and heart-shaped) to the slope stability subjected to an intense rainfall with an intensity of 70 mm/h (prototype scale; corresponding to a return period of 1000 years), via centrifuge modelling. New model roots that have scaled mechanical properties close to real roots were used to simulate transpiration-induced suction in the centrifuge. Transient seepage analyses were performed using SEEP/W to back-analyse the suction responses due to transpiration and rainfall. Subsequently, the back-analysed suction was used to assess the factor of safety of the slopes using SLOPE/W. It is revealed that heart-shaped roots provided greater stabilization effects to a 60° clayey sand slope than tap-shaped roots. The heart-shaped roots induced higher suction, leading to 14% reduction of rainfall infiltration and 6% increase in shear strength. Although transpiration-induced suction in a 45° slope was reduced to zero after the rainfall, mechanical root reinforcement was found to be sufficient to maintain slope stability.

The stability and collapse of lava domes: insight from UAS-derived 4D structure and slope stability models

2020 ◽  
Author(s):  
Brett Carr ◽  
Einat Lev ◽  
Loÿc Vanderkluysen ◽  
Danielle Moyer ◽  
Gayatri Marliyani ◽  
...  
Keyword(s):  
Slope Stability ◽  
Lava Domes ◽  
The Stability

ANALISIS KESTABILAN LERENG DINDING AKHIR DI PIT BARATLAUT PADA PENAMBANGAN BATUBARA DI PT. PUTERA BARA MITRA , KECAMATAN MENTEWE, KALIMANTAN SELATAN

KURVATEK ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 21-34
Author(s):  
Untung Wahyudi ◽  
Excelsior T P ◽  
Luthfi Wahyudi
Keyword(s):  
Slope Stability ◽  
Mining Operation ◽  
Subsurface Water ◽  
Mining System ◽  
Mine Site ◽  
Analysis And Design ◽  
The Stability ◽  
End Wall ◽  
Wall Slope ◽  
Mining Slope

PT. Putera Bara Mitra used open mining system for mining operation, Yet the completion of study on the end wall slope stability that  undertaken by geotechnical PT. Putera Bara Mitra in Northwest Pit and the occured a failure in the low wall on the 1st June 2012 led to the need for analysis and design the overall slope at the mine site. To analyze and design the overall slope, used value of the recommended minimum safety. The value was based on company for single slope SF ≥ 1.2 and SF ≥ 1.3 for overall slope. The calculation used Bichop method with the help of software slide v 5.0. Geometry improvements was done at the low slopes that originally single wall with a 30 m bench height and a slope 70° with SF = 0.781, into 4 levels with SF = 1.305. The analysis explained the factors that affect the stability of the low wall included the mining slope geometry, unfavorable drainase system, material stockpiles and seismicity factors. It was necessary to do prevention efforts to maintain the stability of the slope included the redesign to slope geometry, handling surface and subsurface water in a way to control slopes draining groundwater, vegetation stabilization using and monitoring slope using Total Station with Prism and Crackmeter to determine the movement of cracks visible on the surface. 

Numerical Modeling of Slope Stability Using Revegetation Technique Combined with Geotextiles and Anchors

2019 ◽  
Vol 10 (3) ◽  
pp. 162
Author(s):  
Ghania Boukhatem ◽  
Akram Bouras ◽  
Souhila Rehab Bekkouche ◽  
Djenette Mendjel
Keyword(s):  
Numerical Modeling ◽  
Slope Stability
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