scholarly journals Impact of Crack on Stability of Slope with Linearly Increasing Undrained Strength

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Bing Li ◽  
Fei Zhang ◽  
Di Wang
Keyword(s):  
Slip Surface ◽  
Limit Equilibrium ◽  
Crack Depth ◽  
Seismic Effect ◽  
Tension Crack ◽  
Closed Form Solutions ◽  
Stability Of Slope ◽  
Undrained Strength ◽  
The Stability ◽  
The Impact

This paper presents a procedure for assessment of the impact of tension crack on stability of slope in clays with linearly increasing undrained strength. The procedure is based on the limit equilibrium method with variational extremization. The distribution of the normal stress over slip surface is mathematically obtained for slopes in clays with the linearly increasing undrained strength and then used to determine the tension crack for clays with zero tensile strength. The seismic effect is also included using the pseudostatic approach. Closed-form solutions to the minimum safety factor and the maximum crack depth can be derived and given in the form of chart for convenient use. The results demonstrate a significant effect of the tension crack on the stability of steep slopes, especially for strong seismic conditions. In this situation, neglecting the impact of tension crack in traditional ϕ=0 analyses may overestimate the slope safety. The most adverse location of the tension crack can be also determined and presented in the charts, which may be useful in designing reinforcements and remedial measures for slope stabilization.

Landslide Simulation Using Limit Equilibrium and Finite Element Method

2016 ◽  
Vol 857 ◽  
pp. 555-559 ◽  
Author(s):  
Zuhayr Md Ghazaly ◽  
Mustaqqim Abdul Rahim ◽  
Kok Alfred Chee Jee ◽  
Nur Fitriah Isa ◽  
Liyana Ahmad Sofri
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Main Concern ◽  
Analysis Method ◽  
Stability Of Slope ◽  
The Stability ◽  
Element Method

Slope stability analysis is one of the ancient tasks in the geotechnical engineering. There are two major methods; limit equilibrium method (LEM) and finite element method (FEM) that were used to analyze the factor of safety (FOS) to determine the stability of slope. The factor of safety will affect the remediation method to be underdesign or overdesign if the analysis method was not well chosen. This can lead to safety and costing problems which are the main concern. Furthermore, there were no statement that issued one of the analysis methods was more preferred than another. To achieve the objective of this research, the soil sample collected from landslide at Wang Kelian were tested to obtain the parameters of the soils. Then, those results were inserted into Plaxis and Slope/W software for modeling to obtain the factor of safety based on different cases such as geometry and homogenous of slope. The FOS obtained by FEM was generally lower compared to LEM but LEM can provide an obvious critical slip surface. This can be explained by their principles. Overall, the analysis method chosen must be based on the purpose of the analysis.

Limit equilibrium theory-based investigation on the critical tension crack depth in loess slope

2021 ◽  
Vol 80 (9) ◽  
Author(s):  
Linxuan Zhu ◽  
Zhijun Zhou ◽  
Lei Chen ◽  
Tianyu Xu ◽  
Zhipeng Zhang ◽  
...  
Keyword(s):  
Limit Equilibrium ◽  
Crack Depth ◽  
Equilibrium Theory ◽  
Tension Crack ◽  
Limit Equilibrium Theory ◽  
Loess Slope ◽  
Critical Tension

scholarly journals Optimal profile for concave slopes under static and seismic conditions

2016 ◽  
Vol 53 (9) ◽  
pp. 1522-1532 ◽  
Author(s):  
Farshid Vahedifard ◽  
Shahriar Shahrokhabadi ◽  
Dov Leshchinsky
Keyword(s):  
Limit Equilibrium ◽  
Stable Configuration ◽  
Preliminary Evaluation ◽  
Construction Technology ◽  
Stability Of Slopes ◽  
Optimal Profile ◽  
Stabilized Soil ◽  
The Stability ◽  
Comparison Of The Results ◽  
The Impact

This study presents a methodology to determine the stability and optimal profile for slopes with concave cross section under static and seismic conditions. Concave profiles are observed in some natural slopes suggesting that such geometry is a more stable configuration. In this study, the profile of a concave slope was idealized by a circular arc defined by a single variable, the mid-chord offset (MCO). The proposed concave profile formulation was incorporated into a limit equilibrium–based log spiral slope stability method. Stability charts are presented to show the stability number, MCO, and mode of failure for homogeneous slopes corresponding to the most stable configuration under static and pseudostatic conditions. It is shown that concave profiles can significantly improve the stability of slopes. Under seismic conditions, the impact of concavity is most pronounced. Good agreement was demonstrated upon comparison of the results from the proposed method against those attended from a rigorous upper bound limit analysis. The proposed methodology, along with recent advances in construction technology, can be employed to use concave profiles in trenches, open mine excavations, earth retaining systems, and naturally cemented and stabilized soil slopes. The results presented provide a useful tool for preliminary evaluation for adopting such concave profiles in practice.

Some Relationship between Safety Factor of Earthquake Slope and Related Parameters

2011 ◽  
Vol 422 ◽  
pp. 688-692
Author(s):  
Xiao Hei He ◽  
Geng You Han ◽  
Rui Hua Xiao
Keyword(s):  
Numerical Simulation ◽  
Rock Mechanics ◽  
Safety Factor ◽  
Limit Equilibrium ◽  
Static Method ◽  
Acceleration Coefficient ◽  
The Wenchuan Earthquake ◽  
Stability Of Slope ◽  
The Stability ◽  
The Relationship

Abstract:Since the Wenchuan earthquake happened, the slope stability had been paid much more attention. The safety factor is an important parameter that can be used to evaluate the stability of slope. The pseudo-static method that based on limit equilibrium and the method of numerical simulation can calculate the safety factor accurately, but the velocity that gets the result is slow. If we can establish the relationship between safety factor and some other parameters, then we can calculate the safety factor by using the relationship more quickly. This paper establishes much relationship, such as the relationship between the rock mechanics parameters and the average danymic safety factor, the relationship between the rock mechanics parameters and the ratio of average danymic safety factor to static safety factor, the relationship between the rock mechanics parameters and the average earthquake acceleration coefficient, the relationship between the average earthquake acceleration coefficient and the ratio of average danymic safety factor to static safety factor, and the relationship between the earthquake acceleration coefficient and the ratio of danymic safety factor to static safety factor on the condition of different rock mass.

scholarly journals Stability estimation of slopes with determined slip surface by the MSTAB-3D method based on sliding body limit equilibrium analysis

2019 ◽  
Vol 262 ◽  
pp. 04004
Author(s):  
Janusz Ukleja
Keyword(s):  
Cross Sections ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Equilibrium Analysis ◽  
Limit Equilibrium Analysis ◽  
Modified Method ◽  
3D Elements ◽  
Resultant Forces ◽  
The Impact ◽  
Section Analysis

The method developed for this study, established on the premises of the limit equilibrium flat analysis for a spatial solution, is a modification of the STAB-3D method, previously described by the author. It combines the analyses methods of 2D slices of flat cross–sections with the spatial analyses methodology rooted in a specific breakdown of a landslide sliding body into 3D elements assuming some simplifying solution. However, this method is solely applicable in case of a landslide failure with a stipulated slip surface and with a consistent decline of a determined slide direction. Such a method was developed in the article published earlier, which provided then its basic assumptions and the equilibrium formulations. The following publication thereof, presents overall suppositions for this method as well as its modification involving the resultant forces brought to the equilibrium with the generalized slide direction. Apart from that, a comparative analysis was carried out on the impact of this modification applicability of the obtained results with regard to the STAB-3D method. The algorithm was also presented concerning the modified method with its results being compared to a couple of selected methods LEM (limit equilibrium method). The undertaken analysis reveals that the modified MSTAB-3D method determines stability indicators that are very similar to its earlier version. Moreover, the results occur to be also approximating the values obtained in the course of other methods with regard to the flat cross-section analysis.

scholarly journals Design of Medium Depth Drainage Trench Systems for the Mitigation of Deep Landsliding

Geosciences ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 174
Author(s):  
Federica Cotecchia ◽  
Rossella Petti ◽  
Dario Milella ◽  
Piernicola Lollino
Keyword(s):  
Slip Surface ◽  
Limit Equilibrium ◽  
Drainage System ◽  
Field Studies ◽  
Stability Factor ◽  
Deep Drainage ◽  
Predisposing Factor ◽  
Mitigation Measure ◽  
Transient Seepage ◽  
The Stability

For those slopes where the piezometric regime acts as internal landslide predisposing factor, drainage may represent a more effective mitigation measure than other structural interventions. However, drainage trenches have been generally considered as mitigation measure solely for shallow landslides. More recently, instead, some authors show that the variation in piezometric conditions at large depth is not negligible when medium depth drainage trenches are involved. The paper presents the results of finite element analyses of the transient seepage induced by the installation of systems of drainage trenches of different geometric parameters, and the effect of the drainage system on the stability factor of the slip surface, through 2D limit equilibrium analyses. The pilot region is the Daunia Apennines, where field studies have led to recognize for most of the landslides a “bowl-shaped” slip surface; the results accounting for the Fontana Monte slope at Volturino (Italy), selected as prototype landslide in the assessment of the stabilization efficacy of deep drainage trench systems, is discussed in the following. The study aims at providing indications about the design of the drainage trenches to reduce the pore water pressures on a deep slip surface of such type.

Study on the Influence of Stability for Higher Precipitous Open Pit Slope under Mining Blasting

2011 ◽  
Vol 255-260 ◽  
pp. 3822-3826 ◽  
Author(s):  
Zhi Yu Zhang ◽  
Long Fa Luan ◽  
Ji Yao ◽  
Jian Bin Xie ◽  
Xiang Long Li
Keyword(s):  
Large Deformation ◽  
Limit Equilibrium ◽  
Static Stability ◽  
Open Pit ◽  
Blasting Vibration ◽  
Phosphate Mine ◽  
Stability Of Slope ◽  
The Stability ◽  
Lagrange Element ◽  
Element Method

Based on the hydrological, geologies and slope features of Jianshan phosphate mine in Yunnan province, the geomechanics model of slope was established. Then the static stability of different elevations in mining section was studied by using methods such as the rigid body limit equilibrium method, finite element method, continuum large deformation Lagrange element method. According to the supervise data of the mining blasting, the dynamic response of the slope in blasting was studied by continuum large deformation Lagrange element method, and some suggestions were proposed for following mining blasting. The research results show that the slope was in the stable status before blasting vibration. Current mining blasting vibration has little effect on the stability of slope, but would reduce the safety factor of the top of the slope. Single blasting would enlarge the instantaneous acceleration of the top of the slope in a ratio of 8.8% and 10.8%.

Search of the Most Dangerous in Slide Slope Stability Analysis Based on Genetic Algorithm

2012 ◽  
Vol 166-169 ◽  
pp. 2535-2538
Author(s):  
Ke Wang ◽  
Chang Ming Wang ◽  
Fang Qi ◽  
Cen Cen Niu
Keyword(s):  
Genetic Algorithm ◽  
Stability Analysis ◽  
Slope Stability ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Evolutionary Process ◽  
Limit Equilibrium Method ◽  
Slope Stability Analysis ◽  
Equilibrium Method ◽  
The Stability

The traditional limit equilibrium method in the analysis of slope stability not only exists some subjective empirical hypothesis that can not meet the equilibrium of force and moment, but also ignores the effects of internal stress and strain on the slope stability. Furthermore, in the stability of the slope evaluation, limit equilibrium method relies too much on experience when hypothesizing the slope slip surface. So that it makes deviation on slope analysis and stability evaluation. This paper is based on simplified Bishop method used to establish the model of slope stability analysis. And it used genetic algorithms to solve the minimum safety factor and the most dangerous slip surface of slope. It was the arithmetic which simulates organisms genetic evolutionary process and it avoided the traditional methods falling into the local extreme value point easily and error propagation leading to convergence. The algorithm had advantages of higher accuracy, quick convergence and applicability. It showed that the genetic algorithm is accurate and reliable in the analysis of slope stability.

scholarly journals Investigation on the Stability of Fissured Slopes Reinforced with Anchor Cables under Seismic Action

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Jingwu Zhang ◽  
Mingdong Li ◽  
Jinxiang Yi ◽  
Zhidan Liu
Keyword(s):  
Axial Force ◽  
Upper Bound ◽  
Crack Depth ◽  
Slope Angle ◽  
Optimization Procedure ◽  
Seismic Action ◽  
Upper Bound Theorem ◽  
Critical Location ◽  
The Stability ◽  
The Impact

Based on the upper bound theorem of limit analysis (UBLA) combined with the pseudostatic methods, this paper elaborates on a calculated procedure for evaluating fissured slope stability under seismic conditions reinforced with prestressed anchor cables. An existing simple slope case is presented as a case study in this work. The comparison is given to verify that the solution derived from this study is correct and feasible. By means of a numerical optimization procedure, the critical location of the crack is determined from the best upper bound solutions. The results demonstrate a significant influence of the depth of crack and seismic acceleration coefficient on the critical location distribution of the cracks. Meanwhile, the axial force of anchor cables is investigated via parametric studies. It is shown that the variation of the crack depth has little effect on the axial force of anchor cables. Moreover, this paper also illustrates the variation in the axial force of anchor cables under the impact of five marked factors (crack depth, anchor arrangement, anchor inclination angle, slope angle, and seismic conditions). Finally, the required critical length of the free section of anchor cables is determined to ensure the stability of fissured slopes subjected to seismic action.

An Analysis of the Stability of Hinterland Container Transport Cooperation

2021 ◽  
Vol 55 (5) ◽  
pp. 1170-1186
Author(s):  
Alberto Giudici ◽  
Tao Lu ◽  
Clemens Thielen ◽  
Rob Zuidwijk
Keyword(s):  
Shapley Value ◽  
Minimum Cost ◽  
Limited Range ◽  
Optimization Techniques ◽  
Closed Form Solutions ◽  
Container Transport ◽  
The Shapley Value ◽  
Bargaining Outcome ◽  
The Stability ◽  
The Impact

We study cooperation among hinterland container transport operators that may share transport capacity and demand in corridors between inland and sea ports. We model this transportation problem as a minimum cost flow problem and assume that operators share the total cost based on a bargaining outcome, which has been proven equivalent to the Shapley value. To examine the stability of such cooperation, we perform a sensitivity analysis of the membership of the Shapley value (the bargaining outcome) to the core (the set of stable outcomes) by leveraging a novel concept of parametric cooperative games. We obtain closed-form solutions for identical players that explicitly characterize the impact of overcapacity on the stability of cooperation. For more general cases, we develop a computational approach based on parametric optimization techniques. The numerical results indicate that our primary analytical result, that is, that overcapacity undermines stability, is generally valid, and that overcapacitated networks may permit stable cooperation in only a limited range of settings.

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