On the Stability of Unsaturated Loess Slope under Tunneling Condition

2011 ◽  
Vol 233-235 ◽  
pp. 2678-2681 ◽  
Author(s):  
Xi An Li ◽  
Rong Jian Li ◽  
Gao Feng Che ◽  
Wen Zheng ◽  
Liang Li
Keyword(s):  
Critical Factor ◽  
Matric Suction ◽  
Strength Reduction ◽  
Sliding Surface ◽  
Negative Effects ◽  
Loess Slope ◽  
Stability Of Slope ◽  
The Stability ◽  
Unsaturated Loess ◽  
Work Done

As a unique mode of soil erosion, loess cavities often act as the critical factor to the stability of the highway slopes of unsaturated loess. In this paper, the unsaturated loess slope stabilities are comparatively studied in different cases through the developed program of the strength reduction FEM, such as loess cavities in different position, single- & twin cavities, occurrence and loss of matric suction etc. The work done in this paper revealed the mechanism how the tunneling and the matric suction have effect on the stability of unsaturated loess slope to some extent. The results not only indicate that the loess cavities favor to maintain the stability of slope with the cavities located near the slope's crest, while the loess cavities reduce the stability of slope with the cavities located near the slope's toe, but also disclose that the safety factor of the unsaturated loess slope increases and the potential sliding surface move downward with considering the matric suction and vice versa. In addition, the twin cavities near the slope's toe have the obvious negative effects on slope's stability.

The Instability Mechanism of the Down TuDiLing Landslide

2011 ◽  
Vol 393-395 ◽  
pp. 1558-1561
Author(s):  
Rong Jian Li ◽  
Qiang Xu ◽  
Wen Zheng ◽  
Hung Chou Lin
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Matric Suction ◽  
Strength Reduction ◽  
Sliding Surface ◽  
Residual Shear Strength ◽  
Sliding Mechanism ◽  
Element Computation ◽  
The Stability ◽  
Reinforcement Design

By making use of the developed strength reduction finite element codes based on which the matric suction can be considered, the sliding mechanism of the Down TuDiLing slope is analyzed. The results show that the stability of the Down TuDiLing slope is stable under the condition of employing the peak shear strength of soil and the lose of matric suction, but under the condition of the residual shear strength, the safety factor of the slope is decreasing to instability with the weakening of the matric suction, and a local sliding surface occurs. Through the strength reduction finite element computation, the position of the local sliding surface of slope can be differentiated and determined, so the problem of the local sliding should be paid to more attention in the reinforcement design.

The Analyses on Mechanism and Mode of Instability of Loess Slopes under Surface Loading

2011 ◽  
Vol 243-249 ◽  
pp. 3067-3071
Author(s):  
Rong Jin Li ◽  
Rong Jian Li ◽  
Wen Zheng ◽  
Juan Fang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Loess Soil ◽  
Strength Reduction ◽  
Surface Load ◽  
Soil Slope ◽  
Surface Loading ◽  
Loess Area ◽  
Loess Slope ◽  
The Stability

The contribution of surface load to the stability of loess slope should be properly evaluated in order to meet the engineering demand in loess area. It is essential to analyze the stability of loess soil slope by means of the strength reduction finite element method instead of the slices method commonly used in practice so far. Firstly, some researches on stability of loess slope are reviewed. Then some different cases of the mechanism and mode of instability of a loess slope due to surface load are analyzed in this paper. Numerical results not only indicate that the safety factor of loess slope tends to change with the different distribution of the surface load, but also reveal that the distribution of surface load has important effect on the mode of instability of slope.

Numerical Simulation of Failure Process on Soil Slope with Different Support Measures

2014 ◽  
Vol 580-583 ◽  
pp. 665-668
Author(s):  
Yu Wei Zhang ◽  
Lie Xian Tang ◽  
Da Chuan Bai ◽  
Peng Zhou
Keyword(s):  
Failure Process ◽  
Sliding Surface ◽  
Soil Slope ◽  
Safety Factors ◽  
Slide Mass ◽  
Support Measures ◽  
Conventional Analysis ◽  
Stability Of Slope ◽  
Failure Point ◽  
The Stability

In conventional analysis methods of soil slope, we must presume potential sliding surface at first and then gain the safety factors, judge the stability of slope by the safety factors. In fact, if we know a slope is unstability but don’t know where will be slide or failure, we can’t adopt effective measures to support and prevent the sliding accidents appearing. This paper use RFPA-Centrifuge to numerical simulate the failure of soil slope with different support measures without presume any potential sliding surface, success to gain the failure process and the corresponding safety factors. From the calculate results of RFPA-Centrifuge, we can find where is the first failure point and all the slide mass. So if we can use good analysis software to simulate the failure process of slope and adopt corresponding support measures before the engineering beginning, the stability of slope will be better and the accidents will be disappeared or reduced.

scholarly journals Effect of Dolomite Lime on Soil Matric Suction

2021 ◽  
Vol 3 (01) ◽  
pp. 8-16
Author(s):  
M. I. S. Fazlina ◽  
Putera Agung Maha Agung ◽  
A. T. S. Azhar ◽  
Muhammad Nizam Zakaria ◽  
Mustaffa A. Ahmad ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Unsaturated Soils ◽  
Physical And Mechanical Properties ◽  
Swelling Pressure ◽  
Field Testing ◽  
Matric Suction ◽  
Suction Parameter ◽  
Significant Difference ◽  
Stability Of Slope ◽  
The Stability

The most fundamental of unsaturated soil is matric suction parameter. Matric suction in unsaturated soils plays an important role in controlling physical and mechanical properties. This parameter can influence some other important parameters of soil, such as effective stress, shear strength, swelling pressure, etc. Investigation of matric suction was performed on Ayer Hitam soil, at Batu Pahat District, Johor, Malaysia. Field monitoring works were conducted with and without dolomite treatment at the slopes of Ayer Hitam acidic soil. Field testing used some devices to find out the behavior of matric suction during the rainy session. The result shows that the soil matric suction with dolomite treatment is larger than without treatment and matric suction has a significant difference around 20 – 50 kPa. Enhancement of acidity from the dolomite treatment was not only decreasing pores size caused by the alternating of the microstructure of soil but also leading to increasing the matric suction. The treatment of dolomite material is able to control matric suction and increase the stability of slope acidic Ayer Hitam soil.

Analysis of the Influences of Matric Suction of Unsaturated Soil on the Slope Stability

2012 ◽  
Vol 170-173 ◽  
pp. 3186-3189 ◽  
Author(s):  
Li Wang ◽  
Cui Ran Liu
Keyword(s):  
Slope Stability ◽  
Unsaturated Soil ◽  
Yellow River ◽  
Matric Suction ◽  
Saturated Soil ◽  
Equilibrium Method ◽  
Stability Of Slope ◽  
Ultimate Equilibrium ◽  
The Stability ◽  
Test Result

There is suction in unsaturated soil. This is the most obvious difference between unsaturated soil and saturated soil. It is very difficult to measure it, so research has always been done without account of the influences of matric suction of unsaturated soil. In this paper, based on the test result of engineering characteristics of unsaturated soil from Yellow River Embankments, the stability of slope of Yellow River Embankments is analyzed using ultimate equilibrium method and the influencing rule of matric suction on slope is advanced.

Stability Analysis on High Slope Based on Strength Reduction Method

2014 ◽  
Vol 505-506 ◽  
pp. 234-238
Author(s):  
Bao Jin Ge ◽  
Lian Jun Wang ◽  
Dan Feng Li ◽  
Yi Li
Keyword(s):  
Plastic Deformation ◽  
Stability Analysis ◽  
Reduction Method ◽  
Strength Reduction ◽  
Strength Reduction Method ◽  
High Slope ◽  
Analysis And Evaluation ◽  
Stability Of Slope ◽  
The Stability ◽  
Abaqus Software

The stability analysis and evaluation on high slope is of great significance. The stability analysis on the slope of ZHANG-ZHUO highway is carried on in this paper by using the strength reduction method and ABAQUS software. According to the stress and plastic deformation calculated by ABAQUS software, the paper gives evaluations for the stability of slope. It turns out that safety factor of the slope is greater than three; the stability of the slope is well.

Stability Numerical Simulation of Daping Landslide Group to Sunjiaya Tunnel

2012 ◽  
Vol 170-173 ◽  
pp. 413-417
Author(s):  
Wen She He ◽  
Long Yuan ◽  
Shuang Mei Chang
Keyword(s):  
Numerical Simulation ◽  
Limit Equilibrium ◽  
Simulation Method ◽  
Work Conditions ◽  
Sliding Surface ◽  
Tunnel Engineering ◽  
Safety Factors ◽  
Easy Method ◽  
Stability Of Slope ◽  
The Stability

The stability of two profile, with No.Ⅲ landslide of Daping landslide group near the tunnel engineering of Sunjiaya, was respectively discussed using limit equilibrium and numerical simulation method at operation one (gravity) and two (gravity+rainstorm) in this paper. The dangerous sliding surface and corresponding safety factors was calculated by limit equilibrium method, to upper and lower parts of No.Ⅲ landslide in two different work conditions. The model of two calculation profiles was established and the dangerous sliding surface and corresponding safety factors was simulated by finite difference software of FLAC3D for upper and lower parts of No.Ⅲ landslide at two operations. Compared with limit equilibrium, FLAC3D is a simple and easy method to analyze the stability of slope.

Analysis of Shallow Landslides Stability of Coal Measure Soil through Contact Elastic-Plastic FEM

2011 ◽  
Vol 243-249 ◽  
pp. 2076-2083
Author(s):  
Lei Zhu ◽  
Xin Jiang Song ◽  
Bao Ning Hong
Keyword(s):  
Shallow Landslide ◽  
Shallow Landslides ◽  
Strength Reduction ◽  
Coal Measure ◽  
Actual State ◽  
Sliding Surface ◽  
Safety Factors ◽  
Elastic Plastic ◽  
The Stability ◽  
Shear Strength Reduction

In order to reveal the mechanism of deformation, disintegration and failure of shallow landslides of coal measure soil, through contact elastic-plastic FEM with shear strength reduction, the paper analyzes shallow landslides stability, calculates shallow landslides safety factors, and reveals the mechanism of deformation, disintegration and failure of shallow landslide of coal measure soil. The results are shown as follows: during shallow landslides of coal measure soil, the displacement of sliding mass sliding along sliding surface, the plastic strain of sliding mass and sliding mass sliding state along sliding surface don’t change simultaneously; adopting contact elastic-plastic FEM algorithm may better reflect the actual state and sliding process of shallow landslides of coal measure soil. It can help faithfully reflect real situations of shallow landslides like deformation, disintegration and failure of shallow landslide of coal measure soil, and it may afford one method that can be used as a reference of the stability analysis, accurate evaluation and forecast of this type of landslide.

Seafloor Slope Stability under Adverse Conditions Using Energy Approach

2013 ◽  
Vol 405-408 ◽  
pp. 1445-1448
Author(s):  
Ting Kai Nian ◽  
Bo Liu ◽  
Ping Yin
Keyword(s):  
Slope Stability ◽  
Ocean Waves ◽  
Strength Reduction ◽  
Reduction Technique ◽  
Adverse Conditions ◽  
Strength Reduction Technique ◽  
Stability Of Slope ◽  
The Stability ◽  
Wave Induced ◽  
Kinematic Approach

The effects of ocean waves on the stability of seafloor slopes are of great importance in marine environment. The stability of a seafloor slope considering wave-induced pressure is analyzed using the kinematic approach of limit analysis combined with a strength reduction technique. A seafloor slope without waves is considered first. Furthermore, waved-induced pressure is considered to act on the surface of slope as an external load to analyze the effects on the stability of slope by waves. The results show that the adverse effect of waves on slope stability increases with an increase of the wave height as well as a decrease of the water depth.

Non-Linear Hoek-Brown Shear Strength Reduction Technique Considering the Effect of Dilation

2012 ◽  
Vol 446-449 ◽  
pp. 1524-1530
Author(s):  
Ting Ai ◽  
Ru Zhang ◽  
Li Ren ◽  
Wen Xi Fu
Keyword(s):  
Shear Strength ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Strength Reduction ◽  
Equilibrium Method ◽  
Non Linear ◽  
Stability Of Slope ◽  
The Stability ◽  
Shear Strength Reduction

In order to implement the non-linear Hoek-Brown (HB) shear strength reduction (SSR) on commercially available softwares, this paper derives the relationship between the Drucker-prager (DP) criterion and HB criterion under the condition of plane strain. The equivalent DP parameters can be approximately estimated after serious transformations of parameters between the HB and Mohr-Coulomb (MC) yield functions. To assess the effect of dilation on the stability of slope, the non-associated flow rule, which cannot be contained in the existing limit equilibrium methods, is selected in our analysis, and the SSR-based results of a simple slope indicate that: If the angle of dilatancy ψ is taken to be zero, the factor of safety calculated by the SSR method is very close to that by the limit equilibrium method; if ψ is greater than zero, the factor of safety calculated by the SSR method is greater than that by the limit equilibrium method, and the effect of dilation on the stability of slope can be approximately described by a liner function.

Sign in / Sign up

Export Citation Format

Share Document