scholarly journals The effects of rainfall on the stability of soil slopes in Khanh Vinh district, Khanh Hoa province

2016 ◽  
Vol 19 (1) ◽  
pp. 45-58
Author(s):  
Danh Thanh Nguyen ◽  
Ngo Van Dau ◽  
Dung Quoc Ta
Keyword(s):  
Water Table ◽  
Safety Factor ◽  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Failure Surface ◽  
Residual Soils ◽  
Soil Permeability ◽  
Initial Water ◽  
The Stability

This study presents a procedure for calculating the change of the safety factor for unsaturated slopes of homogenous, residual soils suffering from rainfall infiltration within Khanh Vinh district, Khanh Hòa province. Rainfall is supposed as a main trigger caused failure of the potential sliding slopes. Rainwater into the slope due to infiltration caused an increase in moisture content and negative pore water pressure; a decrease in matric suction and in shear strength on the failure surface. Thus, slopes are reduced stability and can be failed. Soil permeability and rainfall intensity were found to be the primary factors controlling the instability of slopes due to rainfall, while the initial water table location and slope geometry only played a secondary role. A numerical model of analysis coupled seepage-stability used to simulate the seepage and slope stability under conditions of specific environment such as soil permeability, rainfall intensity, water table location and slope geometry in the study area. The relationships between safety factor and rainfall intensity, soil permeability, angle slope, high slope were identified to provide a good indication for the management of landslide hazards under the effects of rainfall.

scholarly journals Slope Stability Analysis Under Pore-Water Pressure: A Case Study in Zarm-Rood Earthfill Dam, Iran

2021 ◽  
Author(s):  
Mojtaba Gholamzade ◽  
Ahad Bagherzadeh Khalkhali
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Pore Water ◽  
Safety Factor ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Slope Stability Analysis ◽  
Operating Conditions ◽  
Successful Implementation ◽  
The Stability

Abstract It is well known that construction of dams or reservoirs have geomorphological impacts on the environment and could potentially accelerate the occurrence of landslides. One of the most common impact is the occurrence of new landslides and activation of the old one, which may turn into a natural disaster. Thus, controlling the stability of landslides become challenging issue specifically in the presence of f pore-water pressure. In general, the presence of water or pore-water pressure reduces the soil resistance and also leads to increase in stimulus loads, resulting in reduction of stability coefficients. In the present study, using GeoStudio SLOPE/W software, the effect of the proximity of the dam reservoir in terms of different operating conditions on the stability analysis of the landslide area of ​​Zarm-Rood Dam is investigated. In the first step, the evaluation of internal stability of landslides and the effect of the presence of water on stability coefficients were evaluated and then the sustainable design of landslides was proposed. It was found that when extra pore-water pressure ranges from 0.2 to 0.4, safety factor is decreased by about 10%. Accordingly, safety factor is decreased by about 17% when extra pore-water pressure range from 0.4 to 0.6. This research demonstrates successful implementation of GeoStudio SLOPE/W for slope stability analysis in dam construction projects.

Stability Analysis of Soil Slope under Strong Earthquake

2014 ◽  
Vol 602-605 ◽  
pp. 598-601 ◽  
Author(s):  
Tie Jun Tao ◽  
En An Chi ◽  
Ming Sheng Zhao ◽  
Qiang Kang
Keyword(s):  
Pore Water ◽  
Safety Factor ◽  
Water Depth ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Time History ◽  
Element Model ◽  
The Stability ◽  
Dynamic Time ◽  
Minimum Safety Factor

Based on the finite element model of slope, the stability of sand slope are studied. The results show that The pore water pressure shows increase trend, while the excess pore water pressure shows decreasing trend with the increase of the water depth. With the increase of the the water depth, safety factor of slope calculated by quasi static reduces to 0.193 from 2.366, which reduces 12.26times. The minimum safety factor calculated by dynamic time history is less than that by quasi static method, which shows that there is some limitations of the quasi static method.Without considering the groundwater, the destruction of slope is mainly the circular shearing damage through the slope toe, while the destruction is not yet through the slope toe, but from a point on the front of slope.

scholarly journals Seismic Stability of Subsea Tunnels Subjected to Seepage

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Xuansheng Cheng ◽  
Yi Ren ◽  
Xiuli Du ◽  
Yida Zhang
Keyword(s):  
Safety Factor ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Time History ◽  
Horizontal Displacement ◽  
Seismic Stability ◽  
Maximum Displacement ◽  
Lining Structure ◽  
The Stability ◽  
Rock Strata

Strength reduction method and ADINA software are adopted to study the stability of submarine tunnel structures subjected to seepage and earthquake under different seawater depths and overlying rock strata thicknesses. First, the excess pore water pressure in the rock mass is eliminated through consolidation calculation. Second, dynamic time-history analysis is performed by inputting the seismic wave to obtain the maximum horizontal displacement at the model top. Finally, static analysis is conducted by inputting the gravity and the lateral border node horizontal displacement when the horizontal displacement is the largest on the top border. The safety factor of a subsea tunnel structure subjected to seepage and earthquake is obtained by continuously reducing the shear strength parameters until the calculation is not convergent. The results show that the plastic zone initially appears at a small scope on the arch feet close to the lining structure and at both sides of the vault. Moreover, the safety factor decreases with increasing seawater depth and overlying rock strata thickness. With increasing seawater depth and overlying rock strata thickness, maximum main stress, effective stress, and maximum displacement increase, whereas displacement amplitude slightly decreases.

scholarly journals Integrated Simulation Modeling Approach for Investigating Pore Water Pressure Induced Landslides

2022 ◽  
Author(s):  
Sahila Beegum ◽  
P J Jainet ◽  
Dawn Emil ◽  
K P Sudheer ◽  
Saurav Das
Keyword(s):  
Pore Water ◽  
Factor Of Safety ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Simulation Models ◽  
Integrated Simulation ◽  
Hill Slope ◽  
Slope Factor ◽  
The Stability ◽  
The Hill

Abstract Soil pore water pressure analysis is crucial for understanding landslide initiation and prediction. However, field-scale transient pore water pressure measurements are complex. This study investigates the integrated application of simulation models (HYDRUS-2D/3D and GeoStudio–Slope/W) to analyze pore water pressure-induced landslides. The proposed methodology is illustrated and validated using a case study (landslide in India, 2018). Model simulated pore water pressure was correlated with the stability of hillslope, and simulation results were found to be co-aligned with the actual landslide that occurred in 2018. Simulations were carried out for natural and modified hill slope geometry in the study area. The volume of water in the hill slope, temporal and spatial evolution of pore water pressure, and factor of safety were analysed. Results indicated higher stability in natural hillslope (factor of safety of 1.243) compared to modified hill slope (factor of safety of 0.946) despite a higher pore water pressure in the natural hillslope. The study demonstrates the integrated applicability of the physics-based models in analyzing the stability of hill slopes under varying pore water pressure and hill slope geometry and its accuracy in predicting future landslides.

scholarly journals Numerical Analysis to Assess the Vertical Drainage Within Flexible Pavement.

2018 ◽  
Vol 7 (4.20) ◽  
pp. 95
Author(s):  
Aqeel Al-Adili ◽  
Rasha H. Abdul-Amir ◽  
Osamah Hassan Chfat
Keyword(s):  
Cross Section ◽  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Flux ◽  
Flexible Pavement ◽  
Laboratory Model ◽  
Typical Structure ◽  
Rainy Period ◽  
Vertical Drainage

In this research the work methodology include the software program SEEP/W routine of the GEOSLOPE 2012; which was used to simulate and analyze the vertical drainage of the pavement cross section using steady-state and transient analysis. A laboratory model consisting of typical structure layers of flexible pavement was considered in this research with a 2% slope with the influence of three different rain intensities (30mm/min, 60mm/min and 90mm/min); in which each one has a duration differs from the other. The results indicated that the value of the pore-water pressure in the surface layer resulting from 90 mm/min rainfall intensity is 83.65% greater than the pressure generated by the 60mm/min intensity of rain and 91.076% greater than the pressure produced from 30mm/min intensity. The average of accumulation water produced by the 30mm/min rainfall intensity in the pavement structure is 44.73 % greater than the average of accumulation of water from the 60mm/min intensity and 77.85% higher than the 90mm/min intensity of rain. The water flux through the pavement cross section during the rainy period of 30 mm/min was 8.42% higher than the water flux of 60 mm/min and 49.82% of the water flux of 90 mm/min intensity of rain.  

The Research of Pore Water Pressure Effect on the Slope Safety Factor Based on Flac

2012 ◽  
Vol 166-169 ◽  
pp. 1433-1436 ◽  
Author(s):  
Hai Bo Liu ◽  
Li Hua Zhang ◽  
Da Hao Lin
Keyword(s):  
Pore Water ◽  
Safety Factor ◽  
Pressure Effect ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Slope Safety

On the basis of the Australian Computer Society(ACADS)`s typical questions1(a),first, regardless of the slope in the case of pore water pressure, used FLAC procedure calculate the safety factor, the result was very close to the reference answer given by ACADS, we can see the accuracy of FLAC. Then, applied to the slope of different pore water pressure, obtained safety factor under corresponding conditions, then, we found that the pore water pressure had effect on the slope safety factor, but the influence are not same, when the pore water pressure less than a certain value, the influence are very small, but, when the pore water pressure exceeded this value, the influence became very large.

scholarly journals Environmental impact of intensive farming in sloping areas

2018 ◽  
Vol 174 ◽  
pp. 01001
Author(s):  
Giovanni Bosco ◽  
Lucia Simeoni
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Sprinkler Irrigation ◽  
High Yield ◽  
Qualitative And Quantitative ◽  
Intensive Farming ◽  
Yield Production ◽  
Large Water ◽  
The Stability ◽  
Irrigation Runoff

The increased demand for food causes intensive farming with high yield production and large water consumption to extend significantly. Depending on soil properties, seasonal rainfall, surface drainage and water resources, hence the consumption-infiltration balance, the ground water table might be raised or depleted; soils could be saturated or remain partly saturated with negative pore pressures. As a result sloping grounds may become prone to shallow slides, as mudflows, or deep seated movements, involving large volumes of soil, especially after rupture of major watering lines or after long uncontrolled irrigations. Within this framework the paper investigates the possible effects of replacing grassland with intensive apple farming on the stability conditions of slopes. Apples require frequent watering, especially during spring and summer to meet qualitative and quantitative productive standards. Also, sprinkler irrigation is often used to protect against hail. From the precipitation, irrigation, runoff, evaporation and plant transpiration balance, the evolution of the pore water pressure distribution within an average year is calculated. Then the modified shear strength of the unsaturated-saturated soils is determined and the factor of safety against sliding is calculated.

Security Control Method of Loading for Surcharge Preloading Based on the Stress Path

2011 ◽  
Vol 368-373 ◽  
pp. 2795-2803
Author(s):  
Heng Hu ◽  
Yan Li ◽  
Zhi Liang Dong ◽  
Yan Luo ◽  
Gong Xin Zhang
Keyword(s):  
Pore Water ◽  
Safety Factor ◽  
Control Method ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Stress Path ◽  
Excess Pore Water Pressure ◽  
Surcharge Preloading ◽  
Security Control ◽  
Excess Pore

All the time, security control method of loading is an important research part in the surcharge preloading, which is directly related to safety of the construction process. Starting from the stress path, discussing the variation of excess pore water pressure and relationship between stress path and security, and bringing forward the control method with a safety factor Fs based on the stress path. By measuring the change of excess pore water pressure, the control method with a safety factor Fs can reflect quantitatively the security status of soil and achieve the purpose of the process control, finally the security control method including the safety factor of loading and speed control is put forward to monitor construction safety. The safety factor of loading Fs is verified and back analyzed with the finite-element software, getting the correction factor from 0.90 to 1.20.

Unsaturated Seepage and Fluid-Solid Coupling Analysis of Rainfall Infiltration of Slope

2011 ◽  
Vol 255-260 ◽  
pp. 3488-3492
Author(s):  
Bao Lin Xiong ◽  
Jing Song Tang ◽  
Chun Jiao Lu
Keyword(s):  
Pore Water ◽  
Unsaturated Flow ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Rainfall Infiltration ◽  
Medium Permeability ◽  
Stability Of Slope ◽  
Transient Seepage ◽  
The Stability ◽  
Unsaturated Seepage

Rainfall is one of the main factors that influence the stability of slope. Rainfall infiltration will cause soil saturation changing and further influence pore water pressure and medium permeability coefficient. Based on porous media saturation-unsaturated flow theory, the slope transient seepage field is simulated under the conditions of rainfall infiltration. It is shown that change of pore water pressure in slope soil lag behind relative changes in rainfall conditions. As the rainfall infiltrate, unsaturated zone in top half of slope become diminution, the soil suction and shear strength reduce, so stabilization of soil slope is reduced.

scholarly journals Seepage Analysis on the Surface Layer of Multistage Filled Slope with Rainfall Infiltration

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Bingxiang Yuan ◽  
Zengrui Cai ◽  
Mengmeng Lu ◽  
Jianbing Lv ◽  
Zhilei Su ◽  
...  
Keyword(s):  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Rainfall Infiltration ◽  
Feature Points ◽  
Saturation State ◽  
Seepage Analysis ◽  
Safety Coefficient ◽  
Infiltration Model ◽  
Saturation Region

Based on the theory of rainfall infiltration, the surface infiltration model of multilevel filled slope was established by using the SEEP/W module of GeoStudio. The changes of the volumetric water content (VWC) and pore water pressure (PWP) in the surface of the slope during the rainfall infiltration were analyzed, and the influence of the change of the rainfall conditions on the VWC and PWP was considered. The analysis showed that VWC and PWP increased when the rain fell, and the growth rate of the higher feature point was higher. The affected area was concentrated on the upper part of the surface about 0.75 m. With the increasing of rainfall intensity, the slope surface getting to transient saturation state was quick, and the time of the PWP increasing to 0 among the feature points of same elevation was shortened. Meanwhile, the PWP presented a positive value, and as the infiltration depth increased, the transient saturation region expanded. The safety coefficient of the multistage filled slope was continuously reduced; after the stop of rainfall, the VWC and the PWP decreased, and the decline rate of the higher feature points was higher. In addition, the PWP of the lower part increased, and the safety factor of the slope presented a trend of rebound.

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