scholarly journals Seismic Active Earth Pressure of Limited Backfill with Curved Slip Surface Considering Intermediate Principal Stress

2021 ◽  
Vol 12 (1) ◽  
pp. 169
Author(s):  
Hui Liu ◽  
Dezhi Kong ◽  
Wensong Gan ◽  
Bingjie Wang

The traditional method for seismic earth pressure calculation has certain limitations for retaining structures under complex conditions. For example, when the soil width is small, the results obtained by the traditional method will be much larger. Therefore, this paper assumes that the soil slip surface is a logarithmic spiral. Based on the plane strain unified strength theory formula, while also considering the soil arching effects and tension cracks, the analytical solutions of the lateral earth pressure coefficient and the active earth pressure under the earthquake action were deduced. The mechanism and distribution of seismic active earth pressure with limited width were discussed in terms of some relevant parameters. The results indicated that the seismic active earth pressure presented a “convex” nonlinear distribution along the retaining structure. As the contribution of the intermediate principal stress increased, the strength limit of the material was effectively utilized, and the earth pressure was reduced by 22.96%. The resultant force increased as the horizontal seismic coefficient increased. However, this effect was no longer evident when the wall–soil friction angle was close to the internal friction angle. The resultant force action point increased with the wall–soil friction angle, and it should be noted that ha>H/3 was true when δ/φ0>0.55. Finally, by drawing a comparison with previous studies, we verified that the method proposed in this paper is reasonable and can provide a new idea for subsequent 3D seismic earth pressure research.

2012 ◽  
Vol 170-173 ◽  
pp. 755-761 ◽  
Author(s):  
Wen Biao Liang ◽  
Jun Hai Zhao ◽  
Yan Li ◽  
Chang Guang Zhang ◽  
Su Wang

Based on the unified solution of shear strength in terms of double stress state variables for unsaturated soils, whilst considering the effect of the intermediate principal stress rationally, the unified solution of Coulomb’s active earth pressure for unsaturated soils without cracks is developed. Comparability of the solution is analyzed and influencing characteristic of each factor is obtained. The research result indicates that: the intermediate principal stress and matric suction have obvious impacts on Coulomb’s active earth pressure for unsaturated soils; Coulomb’s active earth pressure has been decreasing until zero with the increase of unified strength theory parameter and matric suction; Coulomb’s active earth pressure increases with the increase of grading angle of retaining wall and slop angle of backfill, but decreases with the increase of matric suction, effective internal friction angle and matric suction angle, while external friction angle has no obvious influence. The proposed unified solution of Coulomb’s active earth pressure enjoys a wider application, and unified solution of Rankine’s active earth pressure is just the special case. The results are of great significance to soil pressure determination such as slope and foundation pit, and to retaining structures design.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zheng-zhen Wang ◽  
Rang-cheng Kou ◽  
Yong Zhou ◽  
Tian-zhong Ma

At present, most seismic earth pressure theories have the limitations of complex derivation process and difficult solution. To solve these problems, considering the deflection of small principal stress caused by soil arching effect, the central arc soil arch was approximated to two inclined linear soil arches, which can greatly simplify the derivation process. Firstly, by improving the combination of differential thin-layer element method and pseudostatic method, the theoretical formulas of seismic active earth pressure intensity, resultant force size, and resultant force action point under translation mode (T mode) were derived and were verified by experimental results. Then, the influence of soil internal friction angle, wall-soil friction angle, and seismic coefficient on seismic active earth pressure theory was analyzed. The results show that the seismic active earth pressure is nonlinearly distributed, and the seismic horizontal coefficient has a greater influence than other influence factors. The theoretical results can provide reference for the seismic design of retaining wall.


2008 ◽  
Vol 45 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Priyanka Ghosh

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Jiangong Chen ◽  
Zejun Yang ◽  
Richeng Hu ◽  
Haiquan Zhang

In the framework of limit equilibrium theory, the isoperimetric model of functional extremum regarding the seismic active earth pressure is deduced according to the variational method. On this basis, Lagrange multipliers are introduced to convert the problem of seismic active earth pressure into the problem on the functional extremum of two undetermined function arguments. Based on the necessary conditions required for the existence of functional extremum, the function of the slip surface and the normal stress distribution on the slip surface is obtained, and the functional extremum problem is further converted into a function optimization problem with two undetermined Lagrange multipliers. The calculated results show that the slip surface is a plane and the seismic active earth pressure is minimal when the action point is at the lower limit position. As the action point moves upward, the slip surface becomes a logarithmic spiral and the corresponding value of seismic active earth pressure increases in a nonlinear manner. And the seismic active earth pressure is maximal at the upper limit position. The interval estimation constructed by the minimum and maximum values of seismic active earth pressure can provide a reference for the aseismic design of gravity retaining walls.


2012 ◽  
Vol 49 (6) ◽  
pp. 651-658 ◽  
Author(s):  
Pérsio L.A. Barros ◽  
Petrucio J. Santos

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.


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