Determining the unique direction of sliding in three-dimensional slope stability analysis

Xing

Mathematical Problems in Engineering

et al. 2016

The slope stability problem is an important issue for the safety of human beings and structures. The stability analysis of the three-dimensional (3D) slope is essential to prevent landslides, but the most important and difficult problem is how to determine the 3D critical slip surface with the minimum factor of safety in earth slopes. Basing on the slope stress field with the finite element method, a stability analysis method is proposed to determine the critical slip surface and the corresponding safety factor of 3D soil slopes. Spherical and ellipsoidal slip surfaces are considered through the analysis. The moment equilibrium is used to compute the safety factor combined with the Mohr-Coulomb criteria and the limit equilibrium principle. Some assumptions are introduced to reduce the search range of center points and the radius of spheres or ellipsoids. The proposed method is validated by a classical 3D benchmark soil slope. Simulated results indicate that the safety factor of the benchmark slope is 2.14 using the spherical slip surface and 2.19 using the ellipsoidal slip surface, which is close to the results of previous methods. The simulated results indicate that the proposed method can be used for the stability analysis of a 3D soil slope.

Section: Determination Of the Critical Slip Surfacementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Determining the Critical Slip Surface of Three-Dimensional Soil Slopes from the Stress Fields Solved Using the Finite Element Method

Xing

Mathematical Problems in Engineering

et al. 2016

Mathematical Problems in Engineering

“…Huang and Tsai [9] introduced the DOS that defines the direction of movement of the sliding mass in the horizontal plane and proposed a new 3D Bishop's method that satisfies two-direction moment equilibrium. Based on this new concept of 'two-direction equilibrium' , a number of researchers proposed various 3D asymmetrical slope stabilities analysis methods [10,[13][14][15]. Among these methods, simplified Spencer's method proposed by Wan et al [15] satisfies all the force equilibrium and two-direction moment equilibrium.…”

Section: Introductionmentioning

confidence: 99%

“…where x i , y i , and z i are coordinate values of the center of a column base; z ei is the z-coordinate of the center of a column. The unknowns, namely, F, x , z , and a, can be obtained by solving the system of equations consisting of (13), (14), (15), and (16). The presented Spencer's method can be simplified to Bishop's method by considering only moment equilibrium equations (15) and (16) about axes parallel to x-and y-axis direction, respectively.…”

mentioning

confidence: 99%

“…The presented Spencer's method can be simplified to Bishop's method by considering only moment equilibrium equations (15) and (16) about axes parallel to x-and y-axis direction, respectively. Similarly, presented Spencer's method can be simplified to Janbu's simplified method by considering only force equilibrium equations (13) and (14) in x-and yaxis direction, respectively. One more assumption that the intercolumn vertical shear force (X xi and X yi ) is neglected is made in Bishop's and Janbu's simplified method.…”

mentioning

confidence: 99%

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Stability Analysis of Three-Dimensional Slopes Considering the Earthquake Force Direction

Wan

Gao

Zhang

2018

Simplified 3D Spencer’s method is proposed to evaluate the stability of slopes under earthquake force and a random search algorithm is used to determine the critical slip surface. A computer code was written in Matlab to determine the critical slip surface and calculate its safety factor and direction of sliding (DOS). The applicability of the presented code is verified by reanalyzing three slope stability problems. Then, a comparison is made to investigate the effects of the direction of earthquake force on the factor of safety and the DOS of the critical slip surface. Accounting for the effects of the direction of earthquake force, the difference in safety factors, and the DOS can be up to 40% and 40°, respectively. Finally, a parametric study is also conducted to determine the effects of the soil strength parameters (c′, φ′). It is found that the effective cohesion c′ and friction angle φ′ of the soil have nearly no influence on the unique DOS of the critical surface. Application of the presented approach into 3D slopes under quasistatic load is straightforward.

A three‐dimensional limit equilibrium method for slope stability analysis integrating machine learning optimized intercolumn force function

Zhou

2023

Geological Journal

A calculation of the safety factor is the basis of slope stability analysis. The three‐dimensional (3D) limit equilibrium method is one of the most effective safety calculation methods, and ignoring the partial shear force between columns is the most common calculation assumption, which will lead to an unreasonable safety factor. By constraining the range of the intercolumn shear function and the position of the action point of the force between columns and integrating machine learning to optimize the net moment of the column, the simulated annealing algorithm is used to obtain the intercolumn shear function under the minimum net moment, and the safety factor is calculated by using boundary conditions. Finally, proving the accuracy of this method by calculating two examples of commonly used slopes. Example A verifies that the result of the proposed method is more conservative than that of other 3D calculation methods and that the coordinates of the action point of the intercolumn forces in the x and y directions have little influence on safety factor. Example B verifies the applicability of this method to various slope forms. This method fully considers the stress of soil under actual conditions, making the calculation results more reasonable.