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).

Unified Solution of Passive Earth Pressure for Unsaturated Soils

2012 ◽  
Vol 594-597 ◽  
pp. 430-433 ◽  
Author(s):  
Chang Guang Zhang ◽  
Dong Hui Zhu ◽  
Zhi Gao ◽  
Guang Wei Xue ◽  
Zheng Li
Keyword(s):  
Shear Strength ◽  
Unsaturated Soils ◽  
Earth Pressure ◽  
Matric Suction ◽  
Intermediate Principal Stress ◽  
Strength Theory ◽  
Passive Earth Pressure ◽  
Independent State ◽  
Unified Strength Theory ◽  
State Stress

With two different distributions of matric suction, the unified solution of passive earth pressure for unsaturated soils is obtained, which is based on the unified shear strength for unsaturated soils in terms of two independent state stress variables and could avoid some shortages of Rankine's passive earth pressure. The influence of intermediate principal stress and matric suction on passive earth pressure is discussed. The results show that the passive earth pressure increases significantly with the unified strength theory parameter or matric suction increasing, and does not change more rapidly when matric suction decreases linearly with depths than that is constant.

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.

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.

A Nonlinear Constitutive Model for Soil under Complex Stress State

2013 ◽  
Vol 535-536 ◽  
pp. 561-564 ◽  
Author(s):  
Hang Zhou Li ◽  
Hong Jian Liao ◽  
Bo Han ◽  
Li Song
Keyword(s):  
Constitutive Model ◽  
Principal Stress ◽  
Friction Angle ◽  
Complex Stress ◽  
Complex Stress State ◽  
Intermediate Principal Stress ◽  
Strength Theory ◽  
Unified Strength Theory ◽  
Strain Behavior ◽  
Chang Model

It is fundamental to predict the stress-strain behavior of soils to control the stability of the geotechnical engineering. A Duncan-Chang constitutive model is analyzed and found that it ignores the effect of the intermediate principal stress. A unified strength theory is investigated and revised. The lode parameter is introduced into the unified strength theory. The unified friction angle and cohesion which may reflect the influence of the intermediate principal stress and verified by the polyaxial tests are obtained. The compressive strength revised from the unified strength theory is used to replace the Mohr-Coulomb criterion and introduced into the Duncan-Chang model. A modified constitutive model is proposed, which is verified by the plane strain tests. The result shows that the modified constitutive can reflect the effect of the intermediate principal stress, and the Duncan-Chang model is a special case of the modified model when b=0.

Unified Solution of Coulomb’s Active Earth Pressure for Unsaturated Soils without Crack

2012 ◽  
Vol 170-173 ◽  
pp. 755-761 ◽  
Author(s):  
Wen Biao Liang ◽  
Jun Hai Zhao ◽  
Yan Li ◽  
Chang Guang Zhang ◽  
Su Wang
Keyword(s):  
Principal Stress ◽  
Unsaturated Soils ◽  
Retaining Wall ◽  
Research Result ◽  
Earth Pressure ◽  
Friction Angle ◽  
Matric Suction ◽  
Intermediate Principal Stress ◽  
Active Earth Pressure ◽  
Soil Pressure

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.

Influence of Intermediate Principal Stress Effect on Flat Punch Problems

2013 ◽  
Vol 535-536 ◽  
pp. 300-305
Author(s):  
Zong Yuan Ma ◽  
Hong Jian Liao ◽  
Fa Ning Dang
Keyword(s):  
Principal Stress ◽  
Three Dimensional ◽  
Intermediate Principal Stress ◽  
Stress Effect ◽  
Strength Theory ◽  
Lagrangian Analysis ◽  
Flat Punch ◽  
Unified Strength Theory ◽  
Intermediate Principal Stress Effect ◽  
Punch Problem

Using the finite difference code FLAC3D (Fast Lagrangian Analysis of Continua in 3 Dimensions) and UST (Unified Strength Theory), the influence of the intermediate principal stress effect on the problems of flat punch are analyzed in this paper. The values of the ultimate bearing capacity resulting from numerical analyses and the analytical solution of Prandtl’s strip punch problem are compared. The three-dimensional problems of strip, rectangular, square and circular punches on a semi infinite metallic medium have been analyzed.

Analysis of Small Non-Sand Concrete Pile Grouting Pressure Based on Unified Strength Theory

2012 ◽  
Vol 166-169 ◽  
pp. 3095-3099
Author(s):  
Huai Feng Tong
Keyword(s):  
Stress State ◽  
Principal Stress ◽  
Limit State ◽  
Intermediate Principal Stress ◽  
Plastic State ◽  
Strength Theory ◽  
Unified Strength Theory ◽  
Grouting Pressure ◽  
Concrete Pile ◽  
The Relationship

Analysis of stress state of soil around the pile and grouting pressure of small non-sand concrete pile is given based on the expansion elastic theory of cylindrical cavity and the unified strength theory, the grouting pressure formula is obtained in the elastic limit state and elastic-plastic state of soil around the pile considered the intermediate principal stress, and the relationship is obtained between the grouting pressure and the plastic radius; When the soil around the pile is in different stress state, the correlativity of crack and densification of grouting is analyzed, and the relationship between the grouting pressure and the plastic radius is discussed with the right coefficient of the intermediate principal stress and initial press under different values. The obtained results have provided efficient analysis means for grouting optimal design of post-processing technology with small non-sand concrete pile.

Determination of apparent earth pressure diagram for anchored walls in c–φ soil with surcharge

2020 ◽  
Vol 17 (4) ◽  
pp. 481-489
Author(s):  
Seyyed Pouya Alavinezhad ◽  
Hadi Shahir
Keyword(s):  
Retaining Wall ◽  
Ground Surface ◽  
Earth Pressure ◽  
Ground Level ◽  
Content Type ◽  
Lateral Earth Pressure ◽  
The Earth ◽  
Real Distribution ◽  
Strain Modeling

Purpose The purpose of this study is to present a diagram for the lateral earth pressure of c–φ soils exerted on anchored walls in presence of surcharge. Design/methodology/approach To this end, two-dimensional plane strain modeling of anchored wall was carried out in Plaxis software. To validate the numerical model, two excavations with different specifications were simulated and the model results were compared with the available results. Subsequently, a parametric analysis was done and based on its results, a diagram was proposed for the lateral earth pressure of c–φ soils including the surcharge effects. Findings The proposed diagram without the surcharge and cohesion effects is a trapezoidal with zero value at the ground surface that is linearly approaching the apparent earth pressure of sand according to Terzaghi and Peck (1967) at 0.1H (H: wall height). The surcharge and cohesion effects at the ground level is 4 Ka*q and 0, respectively, and below 0.1H, they are treated as the same way for lateral earth pressure of a retaining wall. It should be emphasized that the apparent pressure diagram for design does not resemble the real distribution of earth pressure against the wall and it is for calculating the values of the anchors loads. Originality/value The available diagrams to determine the earth pressure exerted on the anchored walls are related to sandy or clayey soils and do not take the presence of surcharge into account. Thus, the proposed diagram is quite original and different from the previous ones.

The Development and Implementation of Improved Duncan-Chang Constitutive Model in ABAQUS

2011 ◽  
Vol 99-100 ◽  
pp. 965-971
Author(s):  
Zhi Ping Dai ◽  
Cheng Zhao ◽  
Chun Feng Zhao
Keyword(s):  
Constitutive Model ◽  
Principal Stress ◽  
Deformation Behavior ◽  
Fine Sand ◽  
Intermediate Principal Stress ◽  
Strength Theory ◽  
Unified Strength Theory ◽  
Dense Sand ◽  
Improved Model ◽  
Chang Model

As it ignorance the effect of intermediate principal stress, traditional Duncan - Chang model has limitation when applied into geotechnical engineering. It was improved through incorporating the effect of intermediate principal stress based on unified strength theory. Under the help of customized modification platform in ABAQUS, the applicability and stability of the improved model and the reliability of subroutine were validated through simulation of several examples. The results show the improved model can better reflect the deformation behavior of soil through taking the influence of intermediate principal stress into consideration. The improved model in paper can be applied into dense sand, fine sand and clay.

Sign in / Sign up

Export Citation Format

Share Document