Limit Analysis of Slopes Reinforced with Multi-Directional Anchors

2014 ◽  
Vol 501-504 ◽  
pp. 27-31
Author(s):  
Ting Kai Nian ◽  
Kai Liu ◽  
Yan Jun Zhang ◽  
Dong Wang
Keyword(s):  
Upper Bound ◽  
Limit Analysis ◽  
Strength Reduction ◽  
Reduction Technique ◽  
Upper Bound Method ◽  
Optimal Angle ◽  
Strength Reduction Technique ◽  
Parametric Studies ◽  
Earth Slope ◽  
The Stability

The upper-bound method of limit analysis combined with strength reduction technique is employed to analyze the stability of an earth slope reinforced with multi-directional anchors. A homogeneous and isotropic earth slope reinforced with two rows of anchors is considered. Attempts are made to obtain the optimal angles of anchors. Parametric studies show that, for homogeneous and isotropic slopes, the optimal angle of the first row of anchors is 0°; while the optimal angle of the second row of anchors varies with anchor positions, and generally is less than 15°.

scholarly journals Upper Bound Solution of Safety Factor for Shallow Tunnels Face Using a Nonlinear Failure Criterion and Shear Strength Reduction Technique

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Fu Huang ◽  
Zai-lan Li ◽  
Tong-hua Ling
Keyword(s):  
Safety Factor ◽  
Upper Bound ◽  
Reduction Technique ◽  
Nonlinear Failure Criterion ◽  
Upper Bound Theorem ◽  
Tunnel Face ◽  
Bound Solution ◽  
Strength Reduction Technique ◽  
Bound Theorem ◽  
The Stability

A method to evaluate the stability of tunnel face is proposed in the framework of upper bound theorem. The safety factor which is widely applied in slope stability analysis is introduced to estimate the stability of tunnel face using the upper bound theorem of limit analysis in conjunction with a strength reduction technique. Considering almost all geomaterials following a nonlinear failure criterion, a generalized tangential technique is used to calculate the external work and internal energy dissipation in the kinematically admissible velocity field. The upper bound solution of safety factor is obtained by optimization calculation. To evaluate the validity of the method proposed in this paper, the safety factor is compared with those calculated by limit equilibrium method. The comparison shows the solutions derived from these two methods match each other well, which shows the method proposed in this paper can be considered as effective.

Three-dimensional stability evaluation of a preexisting landslide with multiple sliding directions by the strength-reduction technique

2007 ◽  
Vol 44 (3) ◽  
pp. 343-354 ◽  
Author(s):  
J H Deng ◽  
L G Tham ◽  
C F Lee ◽  
Z Y Yang
Keyword(s):  
Slip Band ◽  
Significant Proportion ◽  
Strength Reduction ◽  
Reduction Technique ◽  
Guizhou Province ◽  
Stability Evaluation ◽  
Strength Parameters ◽  
Strength Reduction Technique ◽  
Ground Investigation ◽  
The Stability

Landslide 1 is located on the right bank of the downstream side of the dam for Hongjiadu Hydropower Station in Guizhou Province, China. In view of its close proximity to important workings, the stability of the slide is of great concern. Ground investigation showed that the slide is potentially unstable and has two sliding directions. Reinforcement mainly by piles was proposed as the stabilization measure, but two key questions were raised during the design of the piles. (1) How could the stability of the slope be evaluated, as there are two major sliding directions? (2) How could the shear strength parameters of the slip band be determined, as it contains a significant proportion of coarse particles? In this paper, we demonstrate how these issues can be addressed by the strength-reduction technique. First, the strength parameters of the slip band are back-analyzed by assuming a factor of safety of unity. Second, the major sliding directions are determined by carrying out finite difference analyses. Third, two proposed stabilization schemes are evaluated and compared to demonstrate the versatility of the technique. The present study has demonstrated that the strength-reduction technique is a powerful tool for analyzing such problems.Key words: landslide, reinforcement, piles, stability evaluation, strength-reduction technique.

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.

Probabilistic Strength-Reduction Stability Analysis of Slopes Accounting for 2-D Spatial Variation

2013 ◽  
Vol 535-536 ◽  
pp. 582-585 ◽  
Author(s):  
Jian Ji ◽  
Hong Jian Liao ◽  
Bak Kong Low
Keyword(s):  
Spatial Variation ◽  
Strength Reduction ◽  
Strain Increment ◽  
Reduction Technique ◽  
First Order ◽  
Stability Of Slopes ◽  
Strength Reduction Technique ◽  
Reliability Method ◽  
Reduction Stability ◽  
The Stability

Using the elasto-plastic constitutive model and strength reduction technique, the stability of slopes is analyzed by a finite difference numerical package FLAC version 7.0. Shear strain increment is used to identify the failure zone. Unlike the conventional investigation taking the soil strengths as constant parameters, this study deals with random variables of soil strengths by using first order reliability method (FORM). In particular, two-dimensional (2-D) spatial variation unique to soil strengths is investigated in the reliability analysis.

scholarly journals Stability Charts for Pseudostatic Stability Analysis of Rock Slopes Using the Nonlinear Hoek–Brown Strength Reduction Technique

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Chaowei Sun ◽  
Junrui Chai ◽  
Tao Luo ◽  
Zengguang Xu ◽  
Yuan Qin ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Slope Angle ◽  
Weighting Factor ◽  
Strength Reduction ◽  
Reduction Technique ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
Strength Reduction Technique ◽  
Mass Properties ◽  
The Stability

This paper presents a set of stability charts for the stability assessment of rock slopes that satisfy the Hoek–Brown (HB) criterion under various seismic loading conditions. The nonlinear Hoek–Brown strength reduction technique is used to conduct pseudostatic stability analysis of rock slopes subjected to horizontal seismic excitation. Based on an extensive parametric study, first, a set of stability charts with a slope angle of β = 45° under static and pseudostatic conditions are proposed by using ABAQUS 6.10 software. Second, the slope angle weighting factor (fβ) and the seismic weighting factor (fkh) are adopted to characterize the influence of slope angle (β) and horizontal seismic acceleration coefficient (kh) on the rock slope stability. Finally, the reliability of the proposed charts was validated by three typical examples and two case studies, and the results show that the values of the factor of safety (FOS) obtained from the proposed charts are consistent with the values from other methods. The proposed charts provide an efficient and convenient way to determine the FOS of rock slopes directly from the rock mass properties (γ and σci), the HB parameters (mi and GSI), the slope geometry (H and β), and the horizontal seismic coefficients (kh).

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