Active earth pressure in cohesive soils with an inclined ground surface

2000 ◽  
Vol 37 (1) ◽  
pp. 171-177 ◽  
Author(s):  
Nirmala Gnanapragasam
Keyword(s):  
Analytical Solution ◽  
Ground Surface ◽  
Earth Pressure ◽  
Failure Surface ◽  
Friction Angle ◽  
Active Earth Pressure ◽  
Overburden Pressure ◽  
Retaining Structure ◽  
Lateral Earth Pressure ◽  
Fixed Orientation

An analytical solution is developed to determine the active lateral earth pressure distribution on a retaining structure when it consists of a cohesive backfill (internal friction angle ϕ > 0, cohesion c > 0) with an inclined ground surface. The solution derived encompasses both Bell's equation (for cohesive or cohesionless backfill with a horizontal ground surface) and Rankine's solution (for cohesionless backfill with an inclined ground surface). The orientation of the failure surface is also determined. Results indicate that, unlike the soil-wall scenarios of Bell and Rankine where the failure planes are parallel with a fixed orientation independent of the overburden pressure, for sloping cohesive backfill (ϕ > 0, c > 0) the slope of the failure surface is a function of the overburden pressure and becomes shallower with depth, thus forming a curvilinear failure surface. The solution developed can also be used to check the sustainability of a slope. The analytical solution can be programmed conveniently in a computer.Key words: retaining structure, active earth pressure, cohesive backfill.

Coefficients of active earth pressure with seepage effect

2012 ◽  
Vol 49 (6) ◽  
pp. 651-658 ◽  
Author(s):  
Pérsio L.A. Barros ◽  
Petrucio J. Santos
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Retaining Wall ◽  
Drainage System ◽  
Numerical Procedure ◽  
Ground Surface ◽  
Earth Pressure ◽  
Friction Angle ◽  
Active Earth Pressure ◽  
Plane Failure

A calculation method for the active earth pressure on the possibly inclined face of a retaining wall provided with a drainage system along the soil–structure interface is presented. The soil is cohesionless and fully saturated to the ground surface. This situation may arise during heavy rainstorms. To solve the problem, the water seepage through the soil is first analyzed using a numerical procedure based on the boundary element method. Then, the obtained pore-water pressure is used in a Coulomb-type formulation, which supposes a plane failure surface inside the backfill when the wall movement is enough to put the soil mass in the active state. The formulation provides coefficients of active pressure with seepage effect which can be used to evaluate the active earth thrust on walls of any height. A series of charts with values of the coefficients of active earth pressure with seepage calculated for selected values of the soil internal friction angle, the wall–soil friction angle, and the wall face inclination is presented.

scholarly journals Study on the earth pressure of a foundation pit adjacent to a composite foundation with rigid-flexible and long-short piles

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251985
Author(s):  
Yuancheng Guo ◽  
Shaochuang Gu ◽  
Junwei Jin ◽  
Mingyu Li
Keyword(s):  
Three Dimensional ◽  
Earth Pressure ◽  
Friction Angle ◽  
Element Model ◽  
Composite Foundation ◽  
Deep Soil ◽  
Foundation Pit ◽  
Testing Procedures ◽  
Retaining Structure ◽  
Lateral Earth Pressure

Model tests were performed to investigate the lateral earth pressure acting on the retaining structure adjacent to both natural ground (NG) and composite foundation (CFRLP), which were supported with rigid-flexible and long-short piles. Two testing procedures, namely, applying a load to the foundation and rotating the retaining structure along its toe, were considered. The results indicate that the additional lateral earth pressure acting on the retaining structure adjacent to the CFRLP is less than that of the NG in the depth of the reinforcement area strengthened by flexible piles. Compared with NG, the CFRLP yielded a smaller normalized height of application of the lateral earth pressure, suggesting that the CFRLP blocked the horizontal diffusion of the load and had a strong ability to transfer the surcharge load to the deep soil. When rotating the retaining structure, the lateral earth pressure acting on the upper part of the retaining structure experienced limited reduction once the displacement at the top of the retaining structure was greater than 8 mm, whereas the pressure acting on the lower part of the retaining structure continued to decrease with increasing displacement. In addition, a three-dimensional finite element model (FEM) was used to investigate the influence of the pile parameter and the wall-soil friction angle on the additional lateral earth pressure.

Analytical solution for active pressure of narrow backfills considering arching effect

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sahar Ghobadi ◽  
Hadi Shahir
Keyword(s):  
Analytical Solution ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Back Surface ◽  
Active Earth Pressure ◽  
Soil Pressure ◽  
Principal Stresses ◽  
Content Type ◽  
Arching Effect ◽  
Lateral Earth Pressure

Purpose The purpose of this paper is to study the distribution of active earth pressure in retaining walls with narrow cohesion less backfill considering arching effects. Design/methodology/approach To this end, the approach of principal stresses rotation was used to consider the arching effects. Findings According to the presented formulation, the active soil pressure distribution is nonlinear with zero value at the wall base. The proposed formulation implies that by increasing the frictional forces at both sides of the backfill, the arching effect is increased and so, the lateral earth pressure on the retaining wall is decreased. Also, by narrowing the backfill space, the lateral earth pressure is extremely decreased. Originality/value A comprehensive analytical solution for the active earth pressure of narrow backfills is presented, such that the effects of the surcharge and the characteristics of the stable back surface are considered. The magnitude and height of the application of lateral active force are also derived.

scholarly journals Active Earth Pressure of Limited C-φ Soil Based on Improved Soil Arching Effect

2020 ◽  
Vol 10 (9) ◽  
pp. 3243
Author(s):  
Meilin Liu ◽  
Xiangsheng Chen ◽  
Zhenzhong Hu ◽  
Shuya Liu
Keyword(s):  
Retaining Wall ◽  
Pressure Coefficient ◽  
Ground Surface ◽  
Side Wall ◽  
Earth Pressure ◽  
Active Earth Pressure ◽  
Soil Arching ◽  
Retaining Structure ◽  
Arching Effect ◽  
Soil Arching Effect

For c-φ soil formation (cohesive soil) of limited width with ground surface overload behind a deep retaining structure, a modified active earth pressure calculation model is established in this study. And three key issues are addressed through improved soil arching effect. First, the soil-wall interaction mechanism is determined by considering the soil arching effect. The slip surface of a limited soil is proved to be a double-fold line passing through the retaining wall toe and intersecting the side wall of the existing underground structure until it reaches the ground surface along the existing side wall. Second, the limited width boundary is explicated. And third, the variation in the active earth pressure from parameters of limited c-φ soil is determined. The lateral active earth pressure coefficient is nonlinear distributed based on the improved soil arching effect of the symmetric catenary curve. Furthermore, the active earth pressure distribution, the tension crack at the top of the retaining wall and the resultant force and its action point were obtained. By comparing with the existing analytical methods, such as the Rankine method, it demonstrates that the model proposed in this study is much closer to the measured and numerical results. Ignoring the influence of soil cohesion and the limited width will exponentially reduce the overall stability of the retaining structure and increase the risk of accidents.

Seismic active earth pressure behind a nonvertical retaining wall using pseudo-dynamic analysis

2008 ◽  
Vol 45 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Priyanka Ghosh
Keyword(s):  
Dynamic Analysis ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Failure Surface ◽  
Friction Angle ◽  
Wall Friction ◽  
Active Earth Pressure ◽  
Nonlinear Variation ◽  
Seismic Active Earth Pressure ◽  
Planar Failure

This note describes a study on the seismic active earth pressure behind a nonvertical cantilever retaining wall using pseudo-dynamic analysis. A planar failure surface has been considered behind the retaining wall. The effects of soil friction angle, wall inclination, wall friction angle, amplification of vibration, and horizontal and vertical earthquake acceleration on the active earth pressure have been explored in this study. Unlike the Mononobe–Okabe method, which incorporates pseudo-static analysis, the present analysis predicts a nonlinear variation of active earth pressure along the wall. The results have been compared with the existing values in the literature.

Estimation of the Passive Earth Pressure with Inclined Cohesive Backfills: The Effect of Intermediate Principal Stress is Considered

2010 ◽  
Vol 168-170 ◽  
pp. 1370-1376
Author(s):  
We Long Yu ◽  
Jian Zhang ◽  
Xiu Hua Sun ◽  
Rui Lin Hu ◽  
Xin Wei
Keyword(s):  
Principal Stress ◽  
Retaining Wall ◽  
Ground Surface ◽  
Earth Pressure ◽  
Intermediate Principal Stress ◽  
Strength Theory ◽  
Passive Earth Pressure ◽  
Unified Strength Theory ◽  
Retaining Structure ◽  
Lateral Earth Pressure

Estimating passive earth pressure accurately is very important when designing retaining wall. Based on the unified strength theory and plane strain assumption, an analytical solution has been developed to determine the passive lateral earth pressure distribution on a retaining structure when the backfill is cohesive and inclined considering the effect of the intermediate principal stress. The solution derived encompasses both Bell’s equation (for cohesive or cohesionless backfill with a horizontal ground surface) and Rankine’s solution (for cohesionless backfill with an inclined ground surface).

Seismic uplift capacity of inclined strip anchors

2005 ◽  
Vol 42 (1) ◽  
pp. 263-271 ◽  
Author(s):  
Deepankar Choudhury ◽  
K S Subba Rao
Keyword(s):  
Limit Equilibrium ◽  
Ground Surface ◽  
Failure Surface ◽  
Friction Angle ◽  
Uplift Capacity ◽  
Principle Of Superposition ◽  
Seismic Acceleration ◽  
Acceleration Coefficient ◽  
Angle Of Internal Friction ◽  
Seismic Forces

Uplift capacities of inclined strip anchors in soil with a horizontal ground surface are obtained under seismic conditions. Limit equilibrium approaches with a logarithm-spiral failure surface and pseudostatic seismic forces are adopted in the analysis. The results are presented in the form of seismic uplift capacity factors as functions of anchor inclination, embedment ratio, angle of internal friction of the soil, and horizontal and vertical seismic acceleration coefficients. The uplift capacity factors are worked out separately for cohesion, surcharge, and density components. Use of the principle of superposition for calculating anchor uplift capacity is validated. The vertical seismic acceleration coefficient always reduces the uplift capacity, whereas the horizontal seismic acceleration coefficient reduces the uplift capacity in most cases. The roles of anchor embedment ratio, soil friction angle, and anchor inclination in determination of the seismic uplift capacity are also discussed. Comparisons of the proposed method with available theories in the seismic case are also presented. The present study gives the minimum seismic uplift capacity factors compared with the existing theory.Key words: seismic uplift capacity factors, inclined strip anchors, limit equilibrium, pseudostatic, c–ϕ soil.

Pseudo-Dynamic Active Earth Pressure on Battered Face Retaining Wall Supporting c-Φ Backfill Considering Curvilinear Rupture Surface

2014 ◽  
Vol 5 (1) ◽  
pp. 39-57
Author(s):  
Sima Ghosh ◽  
Arijit Saha
Keyword(s):  
Wave Velocity ◽  
Retaining Wall ◽  
Pressure Coefficient ◽  
Wedge Angle ◽  
Earth Pressure ◽  
Friction Angle ◽  
Active Earth Pressure ◽  
Horizontal Shear ◽  
Rupture Surface ◽  
Wide Range

In the present analysis, using the horizontal slice method and D'Alembert's principle, a methodology is suggested to calculate the pseudo-dynamic active earth pressure on battered face retaining wall supporting cohesive-frictional backfill. Results are presented in tabular form. The analysis provides a curvilinear rupture surface depending on the wall-backfill parameters. Effects of a wide range of variation of parameters like wall inclination angle (a), wall friction angle (d), soil friction angle (F), shear wave velocity (Vs), primary wave velocity (Vp), horizontal and vertical seismic accelerations (kh, kv) along with horizontal shear and vertical loads and non-linear wedge angle on the seismic active earth pressure coefficient have been studied.

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