scholarly journals Landslide Susceptibility in Relation to Correlation of Groundwater Development and Ground Condition

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
S. N. L. Taib ◽  
O. S. Selaman ◽  
C. L. Chen ◽  
R. Lim ◽  
D. S. Awang Ismail
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Slope Angle ◽  
Slip Surfaces ◽  
Slope Modeling ◽  
Pressure Development ◽  
Groundwater Rise ◽  
Ground Condition ◽  
Constant Slope ◽  
The Impact

Rainfall is inevitably one of the main factors that trigger landslides. However, not much study has been conducted on the impact of groundwater rise on slope stability. Thus, this study is intended to focus on the rise of the groundwater level from the bottom of the slope which would lead to landslides due to pore pressure development by eliminating other landslide-triggering factors (i.e., infiltration and surface runoff). Saturated sand was used for slope modeling, and sand densities of 1523 kg/m3, 1562 kg/m3, and 1592 kg/m3 were tested with a constant slope angle of 45°. Another set of experiments was also performed on slopes having angles of 25°, 45°, and 60° and with a maintained density of sand at 1562 kg/m3. Through observation, failure was initiated first at the toe of the slope before minor and major slips or total collapse occurs. Dimensions of slip surfaces were measured and included in SLOPE/W for the computation of the safety factor. In conclusion, safety factors are found to be higher in denser soil and in the lowest slope angle. However, faster occurrence of collapse in denser soil was identified and could be contributed by the faster pore water pressure development.

scholarly journals Geotechnical Study of The Impact of Groundwater Level For Slope Stability in Coal Mine

2019 ◽  
Vol 1 (1) ◽  
pp. 12-21
Author(s):  
Jioni Santo Frans ◽  
Muhammad Hafizh Nurfalaq
Keyword(s):  
Rock Mass ◽  
Slope Stability ◽  
Safety Factor ◽  
Coal Mine ◽  
Groundwater Level ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Slope Angle ◽  
Primary Data ◽  
The Impact

Rock mass has force equilibrium which can be disturbed due to changes in rock mass conditions, both by naturally as well as human activities. In response, rock masses could have instability to reach new equilibrium and trigger landslides. Unstable slopes will affect the safety, economic and social factors. Groundwater has its own problems in mining management. Pore water pressure can cause uplift force and reduce the strength of the rock mass forming slopes and affect the slope stability. The study area has groundwater level relatively close to surface and causes the slope to be in nearly saturated condition. This research aims to study of the effect of groundwater levels on the stability of coal mine slopes in the study area. The research method includes collecting primary data through field observations to collect related technical data and secondary data collection through literature studies. Slope stability analysis was carried out to obtain recommendations with a minimum Safety Factor of 1.30. The results showed the ground water level has an inverse relationship to Safety Factor value. The recommendation is  depressurisation using drain holes. The target of groundwater level reduction in the mine wall is RL+40 in the sidewall area and RL+65 in the highwall area. Another alternative is is by resloping the overall slope angle of the mine wall in the study area. The mine slope is recommended for layback with an overall slope angle of around 24 °.

Investigation of liquefaction and pore water pressure development in layered sands

2008 ◽  
Vol 7 (1) ◽  
pp. 199-219 ◽  
Author(s):  
Pelin Tohumcu Özener ◽  
Kutay Özaydın ◽  
Mehmet M. Berilgen
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Pressure Development

scholarly journals Impact of the moisture content in medium sands on CPTU test results

2016 ◽  
Vol 48 (3) ◽  
pp. 221-231 ◽  
Author(s):  
Łukasz Zawadzki ◽  
Marek Bajda
Keyword(s):  
Moisture Content ◽  
Unsaturated Soils ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Degree Of Saturation ◽  
Test Results ◽  
Time Dynamic ◽  
Tip Resistance ◽  
The Impact ◽  
Resistance Value

Abstract Soils occurring in the soil “active zone” are in contact with the surface and are directly influenced by external factors (mainly climatic changes) that cause variation in their parameters over time. Dynamic and uncontrolled changes of soil properties e.g. due to rainfall and evapotranspiration processes may affect field test results leading to the misinterpretation of the obtained data. This paper presents investigations on the influence of moisture content changes in sandy soils on CPTU results. For this purpose, a field ground model has been constructed and five CPTU tests with a different moisture content of soil were carried out. During the investigations, the tip resistance (qc), friction on sleeve (fs), and pore water pressure (u2) were measured. Moreover, a TDR probe was applied to determine the distribution of the moisture content in the studied soil columns. Differences between CPT results obtained in saturated and unsaturated soils have been shown. Furthermore, a simple equation to correct the tip resistance value due to the impact of the degree of saturation has been proposed.

scholarly journals Boulder Pickup by Tsunami Surge

2019 ◽  
Vol 13 (05n06) ◽  
pp. 1941006
Author(s):  
Samuel Harry ◽  
Margaret Exton ◽  
Harry Yeh
Keyword(s):  
Pore Water Pressure ◽  
Initial Conditions ◽  
Scale Effects ◽  
Traditional Approach ◽  
Water Pressure ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Flow Conditions ◽  
The Difference ◽  
The Impact

Study of boulder transport by tsunamis is challenging because boulder size, shape, and composition vary greatly; furthermore, flow conditions, topography, and initial conditions are generally unknown. To investigate the mechanism of boulder pickup, experiments of tsunami-like flow past spherical boulders partially buried in a sediment bed are conducted. The experiments are performed in a large centrifuge facility to reduce scale effects and the corresponding dynamic similitude is discussed. The traditional approach to determine boulder pickup is adapted for the case of a half-buried spherical boulder. The adapted model predicts that the boulders are transported, but does not accurately predict the timing of pick up. To investigate the difference in pickup timing, two physical phenomena are discussed: pore-water-pressure dissipation in the soil, and the impact of the free-surface flow on hydrodynamic forces. For a spherical shaped boulder, vertical forces (i.e. buoyant and lift forces) are critical for the initiation of boulder pickup. It was found that spherical boulders that are three-quarter buried in the soil are not transported, even when exposed to flow conditions that would otherwise predict transport.

Reinforcement Effect Analysis of Dynamic Drainage Consolidation Based on Finn Constitutive Law

2012 ◽  
Vol 170-173 ◽  
pp. 2390-2394
Author(s):  
Gui Hua Yang ◽  
Wei Yu ◽  
Huai Qi Li
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Constitutive Law ◽  
Effect Analysis ◽  
Engineering Construction ◽  
Drainage Channels ◽  
Speed Up ◽  
Effective Drainage ◽  
The Impact

In coastal areas, soft soil treatment is the challenge which must be faced in process of engineering construction. Among numerous treatment methods, dynamic drainage consolidation method is a new and effective method. In this paper, The Finn constitutive law reflecting dynamic pore pressure has been applied to dynamic drainage consolidation analysis. The results show pore water pressure behaves a pulse response proces for the impact, vertical drainage systerm increase the effective drainage channels, speed up the drainage process.

scholarly journals Influence of Rainfall Intensity on the Stability of Unsaturated Soil Slope: Case Study of R523 Road in Thulamela Municipality, Limpopo Province, South Africa

2020 ◽  
Vol 10 (24) ◽  
pp. 8824
Author(s):  
Fhatuwani Sengani ◽  
François Mulenga
Keyword(s):  
Slope Failure ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Extreme Rainfall ◽  
Limpopo Province ◽  
Slope Instability ◽  
Soil Slope ◽  
Numerical Software ◽  
The Impact

The purpose of this paper was to analyze the impact of extreme rainfall on the recurrence of slope instability using the Thulamela Municipality roads (R523) as a case study. To this end, the historical rainfall data of the area of study were analyzed between 1988 and 2018. The results show that a significant increase in rainfall is usually experienced in the summer months of December and January. Following this, the factor of safety (FoS) of slopes of silt clay, clay, and clay loam soils were estimated using the SLIDE simulator (Numerical software “Finite Element Method (FEM)”) under sunny to rainy conditions of the area. A complementary model, FLACSlope (Numerical software “Finite Difference Method (FDM)”), was utilized to simulate FoS and pore water pressure in sunny and rainy conditions of the area. Simulation results show that extreme rainfall has the ability to reduce the shear strength and resistance of the soil slope material. This may explain the recurrent landslides noted in the area. Finally, the water pore pressure has been simulated to increase with the increased water table, which generally pushes the soil particles apart and reduces the stress between the particles resulting in soil slope failure. Extreme rainfall alters the phase of the material solid in a manner that may require further research for a better understanding.

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