Analytic solutions of rupture angle in coulomb's earth pressure theory

2013 ◽  
Vol 10 (6) ◽  
pp. 573-576
Author(s):  
Zhiguang Guo ◽  
Guoyong Cheng ◽  
Fan Wang
Keyword(s):  
Limit Equilibrium ◽  
Retaining Wall ◽  
Numerical Test ◽  
Engineering Application ◽  
Earth Pressure ◽  
Reference Value ◽  
Failure Surface ◽  
Analytic Solutions ◽  
Foundation Pit ◽  
Simplified Solution

Coulomb's earth pressure theory is widely used in foundation pit supporting structure and retaining wall design, and Rupture angle is one of the key parameters in determining the failure surface location and the foundation pit influence scope. But there is no explicit formula of rupture angle or some wrong in existing formula. This paper, according to the limit equilibrium condition of slide wedge, obtained the analytical expression of Rupture angle which is the most simplified form in the current information. Through the numerical test this simplified solution is consistent with coulomb theory. The conclusion of this paper has some reference value in engineering application of coulomb theory.

scholarly journals Analysis of passive earth pressure modification due to seepage flow effects

2018 ◽  
Vol 55 (5) ◽  
pp. 666-679 ◽  
Author(s):  
Z. Hu ◽  
Z.X. Yang ◽  
S.P. Wilkinson
Keyword(s):  
Limit Equilibrium ◽  
Retaining Wall ◽  
Reaction Force ◽  
Earth Pressure ◽  
Failure Surface ◽  
Friction Angle ◽  
Seepage Flow ◽  
Fourier Series Expansion ◽  
Passive Earth Pressure ◽  
Interface Friction

Using an assumed vertical retaining wall with a drainage system along the soil–structure interface, this paper analyses the effect of anisotropic seepage flow on the development of passive earth pressure. Extremely unfavourable seepage flow inside the backfill, perhaps due to heavy rainfall, will dramatically increase active earth pressure while reducing passive earth pressure, thus increasing the probability of instability of the retaining structure. A trial and error analysis based on limit equilibrium is applied to identify the optimum failure surface. The flow field is computed using Fourier series expansion, and the effective reaction force along the curved failure surface is obtained by solving a modified Kötter equation considering the effect of seepage flow. This approach correlates well with other existing results. For small values of both the internal friction angle and interface friction angle, the failure surface can be appropriately simplified with a planar approximation. A parametric study indicates that the degree of anisotropic seepage flow affects the resulting passive earth pressure. In addition, incremental increases in the effective friction angle and interface friction angle both lead to an increase in passive earth pressure.

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.

Determination of passive earth pressure coefficients using limit equilibrium approach coupled with the Kötter equation

2015 ◽  
Vol 52 (9) ◽  
pp. 1241-1254 ◽  
Author(s):  
Mrunal A. Patki ◽  
J.N. Mandal ◽  
D.M. Dewaikar
Keyword(s):  
Limit Equilibrium ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Failure Surface ◽  
Passive Earth Pressure ◽  
Pressure Coefficients ◽  
Composite Failure ◽  
Equilibrium Approach ◽  
The Moment

A numerical method is developed to evaluate the passive earth pressure coefficients for an inclined rigid retaining wall resting against a horizontal cohesionless backfill. A composite failure surface comprises a log spiral, and its tangent is assumed in the present study. The unique failure surface is identified based on the limit equilibrium approach coupled with the Kötter equation (published in 1903). Force equilibrium conditions are used to evaluate the magnitude of the passive thrust, whereas the moment equilibrium condition is employed to determine the location of the passive thrust. The distinctive feature of the present study is that no assumption is required to be made regarding the point of application of the passive thrust, which would otherwise be an essential criterion with respect to the several limit equilibrium based investigations available in the literature. The passive earth pressure coefficients, Kpγ, are evaluated for various values of soil frictional angle [Formula: see text], wall frictional angle δ, and wall inclination angle λ, and compared with the existing results.

High Pressure Rotary Jet Grouting Pile with Undrained Caisson Combined Construction Technology on Nearby Yangtze River Levee Protection

2013 ◽  
Vol 718-720 ◽  
pp. 1938-1944
Author(s):  
You Sheng Zhao ◽  
Bin Zhou
Keyword(s):  
High Pressure ◽  
Yangtze River ◽  
Engineering Application ◽  
Reference Value ◽  
Construction Technology ◽  
The Yangtze River ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Jet Grouting

t is easy to cause the Yangtze River embankment soil of slip even collapse to have a deep foundation pit construction adjacent to the Yangtze River outsideembankment,there are a lot of risk. In this paper, a new combining technique of construction for large caisson is presented. Based on the construction environment, theconstructiontechnology,the smaller earthwork excavation of deep high pressure rotary jet grouting pile with undrained caisson combined construction technology combined with monitoring data for the open caisson excavation control is adopted. It has achieved relatively good results and summarized the advantages of deep high pressure rotary jet grouting pile with undrained caisson combined construction technology in engineering application owing the reference value for engineering applications.

Seismic passive earth pressure coefficients for sands

2001 ◽  
Vol 38 (4) ◽  
pp. 876-881 ◽  
Author(s):  
Jyant Kumar
Keyword(s):  
Limit Equilibrium ◽  
Earth Pressure ◽  
Logarithmic Spiral ◽  
Failure Surface ◽  
Passive Earth Pressure ◽  
Pressure Coefficients ◽  
Straight Line ◽  
Earth Pressures ◽  
Planar Failure ◽  
Seismic Forces

By taking the failure surface as a combination of the arc of a logarithmic spiral and a straight line, passive earth pressure coefficients in the presence of horizontal pseudostatic earthquake body forces have been computed for an inclined wall placed against cohesionless backfill material. The presence of seismic forces induces a considerable reduction in the passive earth resistance. The reduction increases with an increase in the magnitude of the earthquake acceleration. The effect becomes more predominant for loose sands. The obtained results compared well with those reported in the literature using curved failure surfaces. However, the results available in the literature on the basis of a planar failure surface are found to predict comparatively higher passive resistance.Key words: earth pressures, earthquakes, limit equilibrium, plasticity, retaining walls, sands.

A Double Inequality Method for Calculate the Loading Capacity of a Sheet Pile DIMSP

2012 ◽  
Vol 268-270 ◽  
pp. 725-728
Author(s):  
Yi Huan Xie
Keyword(s):  
Retaining Wall ◽  
Engineering Application ◽  
Earth Pressure ◽  
Plasticity Condition ◽  
Loading Capacity ◽  
Sheet Pile ◽  
Double Inequality ◽  
The Earth ◽  
Additional Correction ◽  
Set Up

The passive earth pressure on the both sides of a sheet pile retaining wall is owing to plasticity bounded, a fact that affects the horizontal loading capacity of the wall. In order to find out a method, that the loading capacity of the wall can be analytically calculated and the mentioned constrain could be token into account, the paper set up a DIMSP model, which consists of mechanics equilibrium principle including two inequalities for the plasticity condition of earth pressure. The deduced solution of the model is capable of calculating the bearing capacity, and possesses the advantages of no additional correction of the cut in depth of the wall. Further more the continuity of earth pressure distribution is ensured by this model, an adjustment of the earth pressure figure is also without difficulty possible. For engineering application some graphics are given, the cut in depth of the wall can be read from them conveniently.

On the Active Failure Surface in the Backfilled Clay behind Rigid Retaining Wall in Slope Engineering

2006 ◽  
Vol 306-308 ◽  
pp. 1497-1502
Author(s):  
X.C. Xu ◽  
Yu Yong Jiao
Keyword(s):  
Variational Principle ◽  
Analytic Solution ◽  
Retaining Wall ◽  
Field Tests ◽  
Earth Pressure ◽  
Failure Surface ◽  
Slope Engineering ◽  
Differential Element ◽  
Element Method

In the classical Coulomb’s earth pressure theory, the failure surface in the backfilled clay behind rigid retaining wall in slope engineering is assumed a plane. However, it has been proved by a number of laboratory and field tests that this failure surface is actually a curving surface. In this paper, based on the vertical differential element method and the variational principle, a new analytic solution to determine the actual failure surface in the backfilled clay is derived, and the effects of the backfilled clay’s properties as well as the effects of the retaining wall’s smoothness are discussed. The result obtained from the proposed approach is compared with Coulomb’s earth pressure theory.

scholarly journals Numerical modeling of progressive failure and its implications for spreads in sensitive clays

2013 ◽  
Vol 50 (9) ◽  
pp. 961-978 ◽  
Author(s):  
Ariane Locat ◽  
Hans Petter Jostad ◽  
Serge Leroueil
Keyword(s):  
Progressive Failure ◽  
Limit Equilibrium ◽  
Pressure Ratio ◽  
Earth Pressure ◽  
High Sensitivity ◽  
Failure Surface ◽  
Soil Mass ◽  
Initiation And Propagation ◽  
Failure Propagation ◽  
Steep Slopes

Spreads are a type of large landslide occurring in sensitive clays. Stability analyses using the limit equilibrium method give factors of safety that are too large and are therefore not applicable to this type of landslide. The progressive failure mechanism is believed to explain the initiation and propagation of the failure surface and the dislocation of the soil mass in horsts and grabens, typical of spreads. A numerical method is presented to identify the parameters influencing progressive failure and to validate the application of this mechanism to spreads. The method evaluates the stresses acting in the slope before failure and models the initiation and propagation of the progressive failure. It is demonstrated that high, steep slopes, with a large earth pressure ratio at rest, are more susceptible to progressive failure and the failure surface propagates over a large distance. Failure is more likely to occur when soil with high brittleness is involved. Soil with low strength at large deformation induces failure propagation over a larger distance. Eastern Canadian clays can exhibit high sensitivity and large brittleness during shear and are susceptible to progressive failure, which explains the occurrence of spreads in these soils.

scholarly journals Arching Effect and Displacement on Theoretical Estimation for Lateral Force Acting on Retaining Wall

2021 ◽  
Author(s):  
Jun-feng Jiang ◽  
Qi-hua Zhao ◽  
Shuairun Zhu ◽  
Sheqin Peng ◽  
Yonghong Wu
Keyword(s):  
Limit Equilibrium ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Friction Angle ◽  
Cohesionless Soil ◽  
Active Earth Pressure ◽  
Theoretical Methods ◽  
Arching Effect ◽  
Comparison Results ◽  
Tension Cracks

Abstract A new approach is proposed to evaluate the non-limit active earth pressure in cohesive-frictional based on the horizontal slices method and limit equilibrium method. This approach takes into account the arching effect, displacement, average shear stress of the soil slice, rupture angle and tension cracks. The accuracy of the proposed method is demonstrated by comparing the experimental results and other theoretical methods. The comparison results show that the proposed approach is suitable for calculating the non-limit active earth pressure in cohesive-frictional soil and cohesionless soil. Additionally, the empirical formulations of the mobilized internal friction angle and soil-wall interface friction angle usually used to cohesionless soil are still applied to cohesive-frictional soil through comparison calculated results of other theoretical methods and finite element method. Some valid formulations of the rupture angle and tension cracks were derived considering the cohesion, wall height, and unit weight.

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