Study on the Mechanism of the Landslide of Heda Expressway K377

2011 ◽  
Vol 255-260 ◽  
pp. 3437-3443 ◽  
Author(s):  
Lei Nie ◽  
Min Zhang ◽  
He Qing Jian

During the construction of Heda expressway, the Ermi landslide, which occurred on section K377, has interrupted the construction of the expressway. Additional engineering geological investigation became necessary. The direct economic losses are over 3 million US dollars. This paper analyzed the Ermi landslide from the aspects of formation process, engineering geological conditions, the structural characteristics and stability analysis of the landslide. The results show that the formation of the Ermi landslide is mainly due to geological conditions in project area. Because the structure of the sliding body is loose and some weak interlayer exists in the slope, the shear strength of the sliding surface and sliding body is low. As cut-slope excavating, the resistant of the slope body reduced. Eventually the slope lost its stability and a landslide formed. In the stability analysis of the slope, the shear strength parameters of the sliding surface was determined by anti-analysis. Therefore, the result of the evaluation is closer to the actual conditions. Analyzing the stability of the three sliding surfaces respectively, the stability factors for initial slope are between 1.211 and 1.468, and the stability factors for current slope are between 0.958 and 1.076. Hence, the cut-slope excavation is the direct cause of the landslide.

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Ziwen Wang ◽  
Jifang Du ◽  
Shuaifeng Wu ◽  
Yingqi Wei ◽  
Jianzhang Xiao ◽  
...  

To identify the water softening mechanisms that caused landslides in Panzhihua Airport, China, property and saturation tests of the mudstones extracted from a representative landslide were proposed. In this paper, water saturation tests were carried out on samples of carbonaceous mudstone collected from the east side of the No. 12 landslide at the airport. A number of different analytical techniques and mechanical tests were used to determine changes in chemical composition, mineral assemblages, and mudstone structural characteristics, including shear strength, after the mudstone had been softened. Three kinds of changes caused by water and three mudstone softening stages are proposed. The results show that the water has a significant influence on the properties of the mudstone, so the stability of the mudstone in the watery period is a big threat to the upper structure. A model for water immersion mudstone strength softening is developed. The model incorporates a permeability coefficient, the hydraulic gradient, and time; the model can be used to determine the mudstone’s shear strength and internal friction angle. This study provides a reference for the study of rock softened by water immersion.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Shijie Chen ◽  
Ming Xiao ◽  
Juntao Chen

A numerical analysis method for block failure is proposed that is based on continuum mechanics. First, a mesh model that includes marked blocks was established based on the grid-based block identification method. Then, expressions of the contact force under various contact states were derived based on the explicit contact force algorithm, and a contact simulation method between blocks and the surrounding rock was proposed. The safety factors of the blocks were calculated based on the strength reduction method. This numerical analysis method can simulate both the continuous deformation of the surrounding rock and the discontinuous failure processes of the blocks. A simple example of a sliding block was used to evaluate the accuracy and rationality of the numerical method. Finally, combined with a deep underground excavation project under complex geological conditions, the stability of the blocks and rock were analyzed. The results indicate that the key blocks are damaged after excavation, the potentially dangerous blocks loosen and undergo large deformations, and the cracks between the blocks and the rock gradually increase as the excavation proceeds. The safety factors of the blocks change during the excavation. The numerical results demonstrate the influence of the surrounding rock on the failure process and on the stability of the blocks, and an effective analysis method is provided for the stability analysis of blocks under complex geological conditions.


2020 ◽  
Vol 8 (9) ◽  
pp. 663
Author(s):  
Han Zhou ◽  
Pengyao Yu ◽  
Xiang Jin ◽  
Tianlin Wang

A disc-type underwater glider (DTUG) has a highly symmetrical shape and is characterized by omnidirectional characteristics and high maneuverability in small bodies of water. To further explore the disc shape’s advantages and characteristics in steering motion, DTUG motion was simulated by Matlab/Simulink. Based on the structural characteristics of DTUG, the motion control equations were established. The simulation of DTUG’s steering motion is carried out and compared with a previous DTUG (LUNA). The sensitivity analysis and Lyapunov stability analysis were also conducted. The results showed that the in situ steering motion can be realized by controlling the position of the center of gravity (CG) of DTUG without moving vertically, which facilitates rapid adjustment of the yaw angle and flexible movement in small bodies of water. The in situ steering motion was significantly affected by the control parameters. The parameter that had the greatest effect on it can be obtained through sensitivity analysis, which can guide DTUG to better adjust the yaw angle under different conditions. The stability analysis showed that the DTUG can remain stable within the range of the control parameter.


2012 ◽  
Vol 170-173 ◽  
pp. 375-379
Author(s):  
Hao Wang ◽  
Zi Xiong Chen ◽  
Dong Ming Zhang

The rocky slope instability has brought great danger to human activity, and often causes economic losses, property damage and casualties, also can cause huge overhead expenses. Rock slope stability analysis must understand the geological conditions as the foundation, be under the analysis to effects of geological factors of rock slope stability, be under the premise of analysis to the engineering geological factors and then make evaluation, this is the best method of analysis and evaluation of stability of rock slope effective. This paper utilizes quick Lagrange difference analysis (FLAC3D) to Zhu Jiadeng landslide in Chongqing, the numerical simulations are to determine the landslide static stability, and provide the basis for management.


2011 ◽  
Vol 250-253 ◽  
pp. 1711-1716
Author(s):  
Li Chao Wang ◽  
Ping Gen Zhou

The limit equilibrium method for rigid body is used to analyze the stability of subgrade reservoir bank slope of granite stained. The sliding of subgrade reservoir bank slope reinforced by dynamic compaction along the interface will not be happened. In the most unfavorable conditions , the sliding surface will be formed inside the stained subgrade, which threatened to the safety operation of the expressway.


2012 ◽  
Vol 204-208 ◽  
pp. 3078-3081
Author(s):  
Kun Yang ◽  
Hao Han ◽  
Zhi Chao Ma

Numerical simulation method is adopted to analysis the stability of tailings dam under the fluid-solid coupled interaction. Using the full-coupled analysis function, stress field 、seepage field and their coupled model are studied in this paper. Finally, the critical sliding surface of the tailings dam is searched. Results show that the safety factor after coupling is smaller than before. It illustrates that the fluid-solid coupling analysis has an important practical significance for the stability analysis of tailings dam.


2019 ◽  
Vol 12 (6) ◽  
pp. 163-169
Author(s):  
C. Rajakumar ◽  
P. Kodanda Rama Rao

The slope stability analysis is always under severe threats in many parts of nilgiris district, causing disruption, loss of human life and economy. The stability of slopes depends on the soil shear strength parameters such as Cohesion, Angle of internal friction, Unit weight of soil and Slope geometry. The stability of a slope is measured by its factor of safety using geometric and shear strength parameter based on infinite slopes. In this research, investigation was carried out at 5 locations in Kattery watershed in nilgiris district. The factor of safety of the slope determined by Mohr Coulomb theory based on shear strength parameter calculated from direct shear test which is a conventional procedure for this study. Artificial. Neural Network (ANN) Model is used to predict the factor of safety. The input parameters for the (ANN) are chosen as Cohesion, Angle of internal friction, Density and Slope angle and the factor of safety as output. The results obtained in ANN method were compared with that of conventional method and observed a good agreement between these two methods.


2016 ◽  
Vol 51 ◽  
pp. 73-76
Author(s):  
Suman Panthee

Stability of rock cut slopes depends upon the type of material, discontinuity attributes and geometry present in any location. Although, gravity remains the constant important factor in dictating the slope failure but other parameters like shear strength and available shear stress along the slope also decides the stability of the slopes to great extent. The strength of the material comes from the internal bonding between the mineral grains, contact between the particles and the ability of the material to respond to the stress conditions. Variation of these material attributes fluctuate the cohesion and angle of internal friction that constitutes the most important properties in defining the strength of any material. Rock resists shear stress by these two internal mechanisms. Numerical simulation by Finite Element Method technique is attempted for assessing the stability cut slope. An attempt has been made in this study to document the behavior of strength of the material in terms of stability of slopes by parametric study of cohesion and internal friction. This study carried to understand how the factor of safety changes with reference to change in cut slope height, cohesion and internal friction of the discontinuities that attributes the shear strength of discontinuities. The study is based on Finite Element Modeling (FEM). From the study it is found that factor of safety has strongly proportional relation with cohesion and internal friction but shown inversely proportional relation with height of cut slope.


2011 ◽  
Vol 393-395 ◽  
pp. 1558-1561
Author(s):  
Rong Jian Li ◽  
Qiang Xu ◽  
Wen Zheng ◽  
Hung Chou Lin

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.


2014 ◽  
Vol 496-500 ◽  
pp. 2520-2522
Author(s):  
Xin Zhe Li ◽  
Juan Liu ◽  
Xin Liang Li

Along with the high-speed rail era, more and more railway construction projects are held in China western area, but the geological conditions in these areas are often complex, so it brings difficulty to the construction of tunnel in building railways. This paper studies the factors influencing the stability of tunnels. It divides these factors into two categories: engineering geological factors and engineering technological factors. Furthermore, it analyzes other factors that affect the stability of tunnels, such as structural characteristics of surrounding rock, mechanics properties of rock mass and construction methods.


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