scholarly journals Stability of Reinforced Retaining Wall under Seismic Loads

2019 ◽  
Vol 9 (11) ◽  
pp. 2175 ◽  
Author(s):  
Liang Jia ◽  
Shikai He ◽  
Na Li ◽  
Wei Wang ◽  
Kai Yao
Keyword(s):  
Slip Surface ◽  
Retaining Wall ◽  
Tensile Force ◽  
Friction Angle ◽  
Unit Weight ◽  
Seismic Load ◽  
Seismic Loads ◽  
The Stability ◽  
Slice Method ◽  
Reinforced Retaining Wall

Based on the horizontal slice method (HSM) and assuming a log spiral slip surface, a method to analyze the stability of a reinforced retaining wall under seismic loads was established in this study by calculating the tensile force of the reinforcement. A parametric study was conducted on the normalized tensile force of the reinforcement, and it was observed that the normalized tensile force tends to increase with acceleration of the seismic load and the height of the backfill. Moreover, it also increases with soil unit weight, while it decreases with increased friction angle of the backfill soil, and the influence of soil cohesion on the normalized tensile force is not significant. The HSM method is proved to be suitable for analyzing the tensile force of reinforcement in retaining walls under seismic loads.

Reliability analysis of the anti-sliding of a retaining wall subjected to seismic loads

2021 ◽  
pp. 1748006X2096428
Author(s):  
Xiao-Cheng Huang ◽  
Xiao-Di Xu ◽  
Qiu-Nan Chen ◽  
Yun-Fu Liu
Keyword(s):  
Reliability Analysis ◽  
Spatial Correlation ◽  
Retaining Wall ◽  
Friction Angle ◽  
Numerical Results ◽  
Seismic Loads ◽  
Full Agreement ◽  
Reliability Based Design ◽  
Complementary Role ◽  
The Stability

Geotechnical engineering involves various types of uncertainties, as it always deals with highly variable natural materials. Reliability-based design/analysis can play at least a complementary role in the design approach. In this paper, reliability analysis of anti-sliding of retaining wall with the parameters treated as random variables is performed based on the concept of random fields. Both friction angle and cohesion of soils near the interface along the base of retaining wall are treated as Gaussian fields. The spatial correlation and cross correlation of the variables are calculated by a specific covariance function and the seismic loads act on retaining walls are also taken into account. Examples are illustrated to verify the accuracy of the proposed approach. It is found from the numerical results that the spatial correlation of shear strength has an important influence on the probability of the anti-sliding failure of retaining wall. Moreover, the numerical results obtained from the proposed method are in full agreement with those obtained from Monte Carlo simulations. Therefore, the proposed method provides a new view to study the stability of a retaining wall subjected to seismic loads.

Formulation of Seismic Passive Resistance of Retaining Wall Backfilled with c-F Soil

2012 ◽  
Vol 3 (2) ◽  
pp. 15-24 ◽  
Author(s):  
Sima Ghosh
Keyword(s):  
Retaining Wall ◽  
Pressure Coefficient ◽  
Earth Pressure ◽  
Friction Angle ◽  
Wall Friction ◽  
Unit Weight ◽  
Passive Resistance ◽  
Angle Of Internal Friction ◽  
Variation Of Parameters ◽  
Wide Range

Knowledge of passive resistance is extremely important and it is the basic data required for the design of geotechnical structures like the retaining wall moving towards the backfill, the foundations, the anchors etc. An attempt is made to develop a formulation for the evolution of seismic passive resistance of a retaining wall supporting c-F backfill using pseudo-static method. Considering a planar rupture surface, the formulation is developed in such a way so that a single critical wedge surface is generated. The variation of seismic passive earth pressure coefficient are studied for wide range of variation of parameters like angle of internal friction, angle of wall friction, cohesion, adhesion, surcharge, unit weight of the backfill material, height and seismic coefficients.

Performance of cement-stabilized retaining walls

2005 ◽  
Vol 42 (3) ◽  
pp. 876-891 ◽  
Author(s):  
M A Ismail
Keyword(s):  
Finite Element ◽  
Retaining Wall ◽  
Friction Angle ◽  
Experimental Program ◽  
Centrifuge Model Test ◽  
Element Analysis ◽  
Centrifuge Testing ◽  
Load Carrying ◽  
The Stability ◽  
Surrounding Soil

This paper investigates the performance of a cement-stabilized retaining wall as a potentially economic solution for supporting vertical cuts in roads and embankments. This investigation was carried out through a comprehensive numerical and experimental program in which the stabilized wall was treated as a c′–ϕ soil. To optimize the design of the stabilized wall, a plane-strain finite element analysis was carried out, using the PLAXIS code, in a parametric study that varied the wall geometry and the shear strength parameters for both the wall and its surrounding soil. The performance of the stabilized retaining wall was verified by a centrifuge model test carried out at an equivalent acceleration of 67g for a sand treated with 3% Portland cement. The results have shown that the load-carrying capacity of the wall is affected primarily by both the cementation of the wall and the friction angle of the surrounding soil. There exists a threshold of cementation beyond which the stability does not increase when the failure mechanism is located completely inside the in situ soil. This critical cementation appears to be a crucial factor in maintaining an economic design for this type of wall. Centrifuge test results confirmed the satisfactory behaviour of cement-stabilized retaining walls.Key words: cement stabilization, retaining wall, cohesion, finite element, centrifuge testing.

Upper Bound Limit Analysis of Passive Earth Pressure of Cohesive Backfill on Retaining Wall

2013 ◽  
Vol 353-356 ◽  
pp. 895-900 ◽  
Author(s):  
Xin Rong Liu ◽  
Ming Xi Ou ◽  
Xin Yang
Keyword(s):  
Upper Bound ◽  
Limit Analysis ◽  
Slip Surface ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Friction Angle ◽  
Cohesive Soil ◽  
Passive Earth Pressure ◽  
Simple Method ◽  
Upper Bound Limit Analysis

In view of the shortage of using classical earth pressure theories to calculating passive earth pressure of cohesive soil on retaining wall under complex conditions. Based on the planar slip surface and the back of retaining wall was inclined and rough assumption, the calculation model of passive earth pressure of cohesive backfill under uniformly distrubuted loads was presented, in which the upper bound limit analysis was adopted. Meanwhile it was proven that the prevailing classical Rankine’s earth pressure theory was a special example simlified under the condition of its assumptions. For it’s difficult to determine the angle of slip surface , a relatively simple method for calculating the angle was proposed by example. And the influence of angle of wall back , friction angle of the interface between soil and retaining wall, cohesion force and internal friction angle of backfill soil to planar sliding surface and passive earth pressure were analyzed. Some good calculation results were achieved, these analysis can provide useful reference for the design of retaining wall.

scholarly journals Calculation of Active Earth Pressure for Narrow Backfill with a Curved Slip Surface

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Zhihui Wang ◽  
Aixiang Wu ◽  
Yiming Wang
Keyword(s):  
Equilibrium Equation ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Failure Surface ◽  
Friction Angle ◽  
Force Balance ◽  
Vertical Force ◽  
The Earth

A method was proposed to calculate the earth pressure from a cohesionless backfill with a high aspect ratio (ratio of height to width of retaining wall). An exponential equation of slip surface was proposed first. The proposed nonlinear slip surface equation can be obtained once the width and height of the backfill as well as the internal friction angle of the backfill were given. The failure surface from the proposed formula agreed well with the experimental slip surface. Then, the earth pressure was calculated using a simplified equilibrium equation based on the proposed slip surface. It is assumed that the minor principal stress of the backfill near the wall and at its corresponding slip surface where the depth is the same is the same. Thus, based on the vertical force balance of the horizontal backfill strip, assuming the wall-soil interface and the slip surface is in the limit equilibrium state, defined by the Mohr–Coulomb criterion, the differential equilibrium equation was obtained and numerically solved. The calculated results agreed well with the test data from the published literature.

Influence of Anisotropic Internal Friction Angle on the Stability of Uniform Soil Slopes

2012 ◽  
Vol 170-173 ◽  
pp. 270-273 ◽  
Author(s):  
Lian Wei Zhang
Keyword(s):  
Slip Surface ◽  
Friction Angle ◽  
Soil Slope ◽  
Critical Slip Surface ◽  
Obvious Effect ◽  
Anisotropic Friction ◽  
Change Of Direction ◽  
Soil Slopes ◽  
Anisotropic Soil ◽  
The Stability

The effect of anisotropy of friction angle in natural deposited soil on the stability of soil slopes was studied in this paper. Stability analysis was performed on a uniform soil slope with anisotropic friction angle. Spencer’s method was used, and the variation of friction angle was assumed to be linear to the change of direction of the slip surface. It was shown that 7-10 percent of change in safety factor might achieve within a 10m-highed anisotropic soil slope. It was also found from the analysis that that frictional anisotropy had no obvious effect on the location of critical slip surface.

scholarly journals Groundwater Fluctuation Simulation in Pagelaran Landslide, Cianjur, Indonesia

2020 ◽  
Vol 11 (1) ◽  
pp. 41
Author(s):  
Twin Hosea Widodo Kristyanto
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
Groundwater Level ◽  
Slip Surface ◽  
Unit Weight ◽  
Undisturbed Soil ◽  
Actual Position ◽  
Groundwater Fluctuation ◽  
Artesian Wells ◽  
The Stability

Pagelaran is one of area in Southern Part of Cianjur. This area has high susceptibility of landslide. One of landslide in Pagelaran, which happened on December 2014, has destroyed 13 houses and damaged vital road along 200 m. A year later, it started to conduct observation regarding the slope. The research aimed to know the role of groundwater level fluctuation in Pagelaran Landslide. The geometry of slope and its slip surface were determined using Electrical Resistivity Tomography. The actual groundwater level was determined by measuring it from surrounding artesian wells. Parameters angle of friction, cohesion, and unit weight were obtained from laboratory tests toward undisturbed soil samples. These data were used for analyzing the actual slope stability condition. Then it was conducted the simulation of slope stability in accordance with fluctuations of groundwater level. The simulation was done by raising the groundwater level with range of 0.5 m. The results showed that the actual slope stability was in critical condition with the value of safety factor 1.044. It also showed that slope stability waned as rising of groundwater level. The value of safety factor was reduced by an average of 0.034 in each 0.5 m up of groundwater level until it became failure (FS<1) when the groundwater level was 0.95 m above the actual position. Therefore, it can be concluded that the position of groundwater level played a role toward the stability of slope in Pagelaran. The rising 0.5 m of groundwater level position will reduce the slope safety factor by 0.034. The slope will become failure if the position of groundwater level rises by 0.95 meter from the actual position. To prevent the rising of groundwater level in rainy season, which can trigger landslide, it can be attached pipes along the slope body to flow the groundwater through them.

scholarly journals Stability of Anchored Retaining Walls Under Seismic Loading Conditions to Obtain Minimal Anchor Lengths Using The Improved Failure Model

2020 ◽  
Vol 30 (3) ◽  
pp. 214-233
Author(s):  
Fatima Zohra Benamara ◽  
Ammar Rouaiguia ◽  
Messaouda Bencheikh
Keyword(s):  
Retaining Wall ◽  
Retaining Walls ◽  
Seismic Load ◽  
Failure Model ◽  
New Model ◽  
Anchor Length ◽  
Earth Pressures ◽  
Internal Forces ◽  
The Stability ◽  
Minimum Safety Factor

Abstract Anchored retaining walls are structures designed to support different loading applied in static and dynamic cases. The purpose of this work is to design and study the stability of an anchored retaining wall loaded with different seismic actions to obtain minimal anchor lengths. Mononobe-Okabe theory has been applied for the evaluation of seismic earth pressures developed behind the anchored wall. Checking the dynamic stability of anchored retaining walls is usually done using the classic Kranz model. To take into consideration the effects of the internal forces developed during failure, we have proposed a new model, based on the Kranz model, which will be used as the Kranz model to find the critical angle failure performed iteratively until the required horizontal anchor length is reached for a minimum safety factor. The results of this study confirm that the effect of the seismic load on the design of an anchored retaining wall, and its stability, has a considerable influence on the estimation of anchor lengths. To validate the modifications made to the new model, a numerical analysis was carried out using the Plaxis 2D software. The interpretation of the obtained results may provide more detailed explanation on the effect of seismic intensities for the design of anchored retaining walls.

scholarly journals Formation of Clay-Rich Layers at The Slip Surface of Slope Instabilities: The Role of Groundwater

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2639
Author(s):  
Julia Castro ◽  
Maria P. Asta ◽  
Jorge P. Galve ◽  
José Miguel Azañón
Keyword(s):  
Clay Minerals ◽  
Slip Surface ◽  
Thick Layer ◽  
Friction Angle ◽  
High Plasticity ◽  
Slide Mass ◽  
Triggering Factor ◽  
Slope Instabilities ◽  
The Stability ◽  
Clay Layers

Some landslides around the world that have low-angle failure planes show exceptionally poor mechanical properties. In some cases, an extraordinarily pure clay layer has been detected on the rupture surface. In this work, a complex landslide, the so-called Diezma landslide, is investigated in a low- to moderate-relief region of Southeast Spain. In this landslide, movement was concentrated on several surfaces that developed on a centimeter-thick layer of smectite (montmorillonite-beidellite) clay-rich level. Since these clayey levels have a very low permeability, high plasticity, and low friction angle, they control the stability of the entire slide mass. Specifically, the triggering factor of this landslide seems to be linked to the infiltration of water from a karstic aquifer located in the head area. The circulation of water through old failure planes could have promoted the active hydrolysis of marly soils to produce new smectite clay minerals. Here, by using geophysical, mineralogical, and geochemical modelling methods, we reveal that the formation and dissolution of carbonates, sulfates, and clay minerals in the Diezma landslide could explain the elevated concentrations of highly plastic secondary clays in its slip surface. This study may help in the understanding of landslides that show secondary clay layers coinciding to their low-angle failure planes.

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