scholarly journals A Computational Method of Active Earth Pressure from Finite Soil Body

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Yi Tang ◽  
Jiangong Chen

Nowadays, Coulomb and Rankine earth pressure theories have been widely applied to solve the earth pressure on a retaining structure. However, both of the theories established on the basis of the semi-infinite space assumption are not suitable for calculating the earth pressure from finite soil body. Therefore, this paper focuses on a theoretical study about the active earth pressure from finite soil body. Firstly, a common calculation model of finite soil body is established according to the results of previous studies. And then, based on Coulomb’s theory and the wedge element method, an analytical solution of the unit active earth pressure from finite soil body is deduced without an assumption of its linear distribution in advance. Meanwhile, formulas of the active earth pressure strength coefficient and the application point of the resultant force are also deduced. Finally, the influence of parameters such as the frictional angle between the retaining wall back and backfill, slope angle of backfill, dip angle of the retaining wall back, the frictional angle between backfill and rock slope, and uniformly applied load on the backfill surface on the distribution of the unit active earth pressure and the application point of the resultant force is analyzed in detail.

2011 ◽  
Vol 90-93 ◽  
pp. 433-437 ◽  
Author(s):  
Jian Gong Chen ◽  
Mei Lin Deng ◽  
Yong Xing Zhang

On the basis of coulomb’s concept that the active earth pressure against the back of a retaining wall is due to the thrust force exerted by a sliding wedge of soil between the back of the wall and a plane which passes through the bottom edge of the wall and has an inclination of θ, two basis differential equations of first order are set up by considering the equilibrium of the forces and the moments on a partial wedge of soil. The distributing coefficient of active earth pressure is obtained through comparing two basis equations. The unit earth pressure and the application point of the resultant force are deduced. The effects of parameters such as the internal frictional angle of backfill, the frictional angle between the wall back and the backfill, slope angle of filling and dip angle of wall back on distributing coefficient of active earth pressure, the unit earth pressure, the application point of the resultant force, rupture angle are analyzed in detail. Meanwhile the non-linear distributing features are concluded.


2019 ◽  
Vol 4 (2) ◽  
pp. 15
Author(s):  
Nimbalkar ◽  
Pain ◽  
Ahmad ◽  
Chen

An accurate estimation of static and seismic earth pressures is extremely important in geotechnical design. The conventional Coulomb’s approach and Mononobe-Okabe’s approach have been widely used in engineering practice. However, the latter approach provides the linear distribution of seismic earth pressure behind a retaining wall in an approximate way. Therefore, the pseudo-dynamic method can be used to compute the distribution of seismic active earth pressure in a more realistic manner. The effect of wall and soil inertia must be considered for the design of a retaining wall under seismic conditions. The method proposed considers the propagation of shear and primary waves through the backfill soil and the retaining wall due to seismic excitation. The crude estimate of finding the approximate seismic acceleration makes the pseudo-static approach often unreliable to adopt in the stability assessment of retaining walls. The predictions of the active earth pressure using Coulomb theory are not consistent with the laboratory results to the development of arching in the backfill soil. A new method is proposed to compute the active earth pressure acting on the backface of a rigid retaining wall undergoing horizontal translation. The predictions of the proposed method are verified against results of laboratory tests as well as the results from other methods proposed in the past.


2009 ◽  
Vol 46 (10) ◽  
pp. 1216-1228 ◽  
Author(s):  
Kyuho Paik ◽  
Myung Sagong ◽  
Hyungjoo Lee

Arching effects in backfill materials generate a nonlinear active earth-pressure distribution behind a rough, rigid retaining wall. There are several analyses for estimating the nonlinear active earth pressures on a retaining wall exerted by a homogeneous backfill in the presence of arching. However, it is not possible to use these analyses for a caisson backfilled with crushed rock and sand, which is common in marine structures. In this study, a new formulation is proposed for calculating the nonlinear active earth pressure acting on a caisson backfilled with crushed rock and sand. The new formulation allows important insights, including the dependence of the slope angle of the crushed rock – sand interface that minimizes the active force and overturning moment on the caisson on the shear strengths of the crushed rock and sand and the geometry of the problem.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Weidong Hu ◽  
Kangxing Liu ◽  
Xinnian Zhu ◽  
Xiaolong Tong ◽  
Xiyu Zhou

The horizontal differential layer element method was used to study the active earth pressure of the finite-width soil formed by the rigid retaining wall for the embankment or adjacent foundation pits. The cohesionless soil was taken as the research object, and the soil arch theory was introduced based on the translation mode of rigid retaining wall and the linear sliding fracture surface. The minor principal stress line was assumed as circular, considering the deflected principal stress as soil arching effect. The shear stress between level soil layers in the failure wedge was calculated, and the differential level layer method was modified. Then, the theoretical formula of the active earth pressure, the resultant earth pressure, and the point of application of resultant earth pressure were obtained using this revised method. The predictions by the proposed formula were compared with the existing methods combined with the cases. It is shown that the resultant finite pressure increases gradually and approaches to Coulomb active earth pressure values when the soil is infinite, with the increase of the ratios of the backfill width to height. Moreover, the horizontal pressure for limited soils is distributed nonlinearly along the wall height. Considering the shear stress between level soil layers and the soil arching effect, the position of application point of the resultant active earth pressure by the proposed formulation is higher than that of Coulomb’s solution. The wall is rougher, and the resultant pressure will be smaller. The application point distance from the bottom of the wall will increase. Finally, an experiment was conducted to verify the distribution of the active earth pressure for finite soil against rigid retaining wall, and the research results agree well with those of the experimented observations.


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.


2013 ◽  
Vol 353-356 ◽  
pp. 2073-2078
Author(s):  
Tian Zhong Ma ◽  
Yan Peng Zhu ◽  
Chun Jing Lai ◽  
De Ju Meng

Slope anchorage structure of soil nail is a kind of economic and effective flexible slope supporting structure. This structure at present is widely used in China. The supporting structure belong to permanent slope anchorage structure, so the design must consider earthquake action. Its methods of dynamical analysis and seismic design can not be found for the time being. The seismic design theory and method of traditional rigidity retaining wall have not competent for this new type of flexible supporting structure analysis and design. Because the acceleration along the slope height has amplification effect under horizontal earthquake action, errors should be induced in calculating earthquake earth pressure using the constant acceleration along the slope height. Considering the linear change of the acceleration along the slope height and unstable soil with the fortification intensity the influence of the peak acceleration, the earthquake earth pressure calculation formula is deduced. The soil nailing slope anchorage structure seismic dynamic calculation model is established and the analytical solutions are obtained. The seismic design and calculation method are given. Finally this method is applied to a case record for illustration of its capability. The results show that soil nailing slope anchorage structure has good aseismic performance, the calculation method of soil nailing slope anchorage structure seismic design is simple, practical, effective. The calculation model provides theory basis for the soil nailing slope anchorage structure of seismic design. Key words: soil nailing; slope; earthquake action; seismic design;


1888 ◽  
Vol 14 ◽  
pp. 85-97
Author(s):  
A. C. Elliott ◽  
Armstrong

There are two main distinct methods of attacking the problem of the retaining wall. The first in chronological order is due to Coulomb, and is variously named, perhaps most commonly as the method of the Wedge of Least Eesistance. Briefly characterised, it might be said to depend upon the mathematical artifice of finding the resultant force due to the mutual action of the earth mass, and the wall a maximum, the earth being supposed to yield incipiently under the action of its weight, and in opposition to friction and the reaction in question, along an inclined plane determined so as to fulfil that imposed condition. Coulomb's method has been developed by various writers, and may be regarded as complete.


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