scholarly journals Design Diagrams for the Analysis of Active Pressure on Retaining Walls with the Effect of Line Surcharge

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Mojtaba Ahmadabadi ◽  
Mohammad Karim Faghirizadeh
Keyword(s):  
Pressure Distribution ◽  
Lateral Pressure ◽  
Limit Equilibrium ◽  
Pressure Coefficient ◽  
Failure Surface ◽  
Retaining Walls ◽  
Software Environment ◽  
Active Pressure ◽  
Failure Wedge ◽  
Different Soils

In this study, a formulation has been proposed to calculate the pressure on wall and determine the angle of failure wedge based on limit equilibrium method. The mentioned formulation is capable of calculating active pressure coefficient, culmination of forces in failure surface, and pressure distribution on wall with the effect of line surcharge. In addition, based on the proposed method, a simple formula has been proposed to calculate the angle of failure wedge by the effect of surcharge. Moreover, the proposed approach has the advantage of taking into account the effect of surcharge on elastoplastic environment by considering the parameters of soil and determining the extent to which the surcharge is effective in pressure distribution on the wall. However, in most previous methods and specifications, resultant lateral pressure from surcharge in elastic environment had been considered. Finally, based on the obtained results, the design diagrams for different soils and different surcharges have been proposed. According to these diagrams, pressure on wall, pressure distribution on wall, and angle of failure wedge will easily be achieved. Also, a computer program has been written in MATLAB software environment. Using the results of these codes, the pressure on wall with the effect of surcharge, the angle of failure wedge, and pressure distribution on wall will be determined.

Limit equilibrium computation of dynamic passive earth pressure

1995 ◽  
Vol 32 (3) ◽  
pp. 481-487 ◽  
Author(s):  
Ernest E. Morrison Jr. ◽  
Robert M. Ebeling
Keyword(s):  
Limit Equilibrium ◽  
Pressure Coefficient ◽  
Earth Pressure ◽  
Failure Surface ◽  
Friction Angle ◽  
Passive Earth Pressure ◽  
Equilibrium Equations ◽  
Cohesionless Soils ◽  
Earth Pressures ◽  
Earth Pressure Coefficient

Few solution techniques exist for the determination of pseudostatic dynamic passive earth pressures for cohesionless soils. The widely accepted Mononobe–Okabe equation can result in the computing of unconservative values if the wall interface friction angle is greater than half the soil internal friction angle. As an alternate solution, equilibrium equations were formulated assuming a log spiral failure surface, and a research computer program was written to calculate the dynamic passive earth pressure coefficient. The primary purpose of this paper is to present a comparison of results obtained using the Mononobe–Okabe equation with those obtained using the log spiral formulation. Key words : pseudostatic, dynamic, passive earth pressure.

scholarly journals A Pseudodynamic Approach of Seismic Active Pressure on Retaining Walls Based on a Curved Rupture Surface

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Zuofei Yan ◽  
Yahong Deng ◽  
Jia He ◽  
You Xuan ◽  
Wei Wu
Keyword(s):  
Limit Equilibrium ◽  
Earth Pressure ◽  
Logarithmic Spiral ◽  
Failure Surface ◽  
Friction Angle ◽  
Retaining Walls ◽  
Rupture Surface ◽  
Straight Line ◽  
Dynamic Earth Pressure

Reasonable determination of the magnitude and distribution of dynamic earth pressure is one of the major challenges in the seismic design of retaining walls. Based on the principles of pseudodynamic method, the present study assumed that the critical rupture surface of backfill soil was a composite curved surface which was in combination with a logarithmic spiral and straight line. The equations for the calculation of seismic total active thrusts on retaining walls were derived using limit equilibrium theory, and earth pressure distribution was obtained by differentiating total active thrusts. The effects of initial phase, amplification factor, and soil friction angle on the distribution of seismic active earth pressure have also been discussed. Compared to pseudostatic and pseudodynamic methods for the determination of planar failure surface forms, the proposed method receives a bit lower value of seismic active earth pressures.

Upper-bound approach for analysis of cantilever retaining walls

2010 ◽  
Vol 47 (9) ◽  
pp. 999-1010 ◽  
Author(s):  
H. Vrecl Kojc ◽  
L. Trauner
Keyword(s):  
Limit Equilibrium ◽  
Pressure Coefficient ◽  
Vertical Component ◽  
Retaining Walls ◽  
Embedment Depth ◽  
Vertical Force ◽  
Soil Pressure ◽  
Limit States ◽  
Passive Pressure ◽  
Cantilever Retaining Walls

The proposed method for the analysis of cantilever retaining walls is based on ultimate limit states, but in contrast to other methods, which are recognized worldwide, also considers the condition of vertical force equilibrium, which includes the wall unit weight and the vertical component of the soil–structure interaction. The two-dimensional analytical model with polygonal soil pressure distribution is based on two new characteristics: the parameter α and the passive pressure coefficient at the embedment depth, Kb. The kinematic approach of limit analysis is used to examine the limit equilibrium state of the cantilever retaining wall according to soil properties and other loadings. The failure mechanism, composed of a classical determination of the passive pressure in the embedded part of the wall and a kinematically admissible velocity field at the retained side of the wall, estimates the limiting value of the passive earth pressure at the embedment depth. The advantage of the proposed method is that it enables the design of more slender cantilever retaining walls, at which the comparable level of safety for geotechnical and structural bearing capacity limit states is reached, which is the basic condition for safe design of retaining structures.

scholarly journals Numerical Study on Damage Zones Induced by Excavation and Ventilation in a High-Temperature Tunnel at Depth

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4773
Author(s):  
Jianyu Li ◽  
Hong Li ◽  
Zheming Zhu ◽  
Ye Tao ◽  
Chun’an Tang
Keyword(s):  
High Temperature ◽  
Lateral Pressure ◽  
Numerical Study ◽  
Pressure Coefficient ◽  
Fracture Morphology ◽  
In Situ Stress ◽  
Surrounding Rock ◽  
Geothermal System ◽  
Mechanical Coupling ◽  
Lateral Pressure Coefficient

Geothermal power is being regarded as depending on techniques derived from hydrocarbon production in worldwide current strategy. However, it has artificially been developed far less than its natural potentials due to technical restrictions. This paper introduces the Enhanced Geothermal System based on Excavation (EGS-E), which is an innovative scheme of geothermal energy extraction. Then, based on cohesion-weakening-friction-strengthening model (CWFS) and literature investigation of granite test at high temperature, the initiation, propagation of excavation damaged zones (EDZs) under unloading and the EDZs scale in EGS-E closed to hydrostatic pressure state is studied. Finally, we have a discussion about the further evolution of surrounding rock stress and EDZs during ventilation is studied by thermal-mechanical coupling. The results show that the influence of high temperature damage on the mechanical parameters of granite should be considered; Lateral pressure coefficient affects the fracture morphology and scale of tunnel surrounding rock, and EDZs area is larger when the lateral pressure coefficient is 1.0 or 1.2; Ventilation of high temperature and high in-situ stress tunnel have a significant effect on the EDZs scale; Additional tensile stress is generated in the shallow of tunnel surrounding rock, and the compressive stress concentration transfers to the deep. EDZs experiences three expansion stages of slow, rapid and deceleration with cooling time, and the thermal insulation layer prolongs the slow growth stage.

Lateral Earth Pressure Coefficient of Soils Subjected to Freeze–Thaw

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Xiaodong Zhao ◽  
Guoqing Zhou ◽  
Bo Wang ◽  
Wei Jiao ◽  
Jing Yu
Keyword(s):  
Pressure Coefficient ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Saturated Soil ◽  
Frozen Soils ◽  
Freeze Thaw ◽  
Lateral Earth Pressure ◽  
Soil Deposits ◽  
Earth Pressure Coefficient ◽  
Water Saturated

Artificial frozen soils (AFS) have been used widely as temporary retaining walls in strata with soft and water-saturated soil deposits. After excavations, frozen soils thaw, and the lateral earth pressure penetrates through the soils subjected to freeze–thaw, and acts on man-made facilities. Therefore, it is important to investigate the lateral pressure (coefficient) responses of soils subjected to freeze–thaw to perform structure calculations and stability assessments of man-made facilities. A cubical testing apparatus was developed, and tests were performed on susceptible soils under conditions of freezing to a stable thermal gradient and then thawing with a uniform temperature (Fnonuni–Tuni). The experimental results indicated a lack of notable anisotropy for the maximum lateral preconsolidated pressures induced by the specimen’s compaction and freeze–thaw. However, the freeze–thaw led to a decrement of lateral earth pressure coefficient  K0, and  K0 decrement under the horizontal Fnonuni–Tuni was greater than that under the vertical Fnonuni–Tuni. The measured  K0 for normally consolidated and over-consolidated soil specimens exhibited anisotropic characteristics under the vertical Fnonuni–Tuni and horizontal Fnonuni–Tuni treatments. The anisotropies of  K0 under the horizontal Fnonuni–Tuni were greater than that under the vertical Fnonuni–Tuni, and the anisotropies were more noticeable in the unloading path than that in the loading path. These observations have potential significances to the economical and practical design of permanent retaining walls in soft and water-saturated soil deposits.

DISLOCATION OF FACE-SLABS OF ZIPINGPU CONCRETE FACE ROCKFILL DAM DURING WENCHUAN EARTHQUAKE

2012 ◽  
Vol 06 (02) ◽  
pp. 1250007 ◽  
Author(s):  
DEGAO ZOU ◽  
YANG ZHOU ◽  
HOE I. LING ◽  
XIANJING KONG ◽  
BIN XU
Keyword(s):  
Wenchuan Earthquake ◽  
Limit Equilibrium ◽  
Failure Surface ◽  
Ground Acceleration ◽  
Factors Affecting ◽  
2008 Wenchuan Earthquake ◽  
Rockfill Dam ◽  
Concrete Face ◽  
Concrete Face Rockfill Dam ◽  
Water Elevation

Zipingpu concrete face rockfill dam (CFRD) is one of the tallest dams that have ever been subjected to strong earthquake shaking and recorded damages. In this paper, finite element method and limit equilibrium method are used to determine the most critical failure surface for Zipingpu CFRD during the 2008 Wenchuan earthquake in China. The dislocation damage of the face-slab joint was then obtained from the sliding block analysis. The major factors affecting dislocation displacement of face-slabs were analyzed. The results showed that the rigid sliding block method is relevant for analyzing the damage of face-slabs of CFRD during earthquake. The peak ground acceleration had a significant influence on the dislocation. As the acceleration of the dam increases with the height while the strength of face-slab joints reduces, the dislocation could easily occur when the upstream slope of the dam started to slide. The water elevation had considerable impact on the dislocation of face-slabs during strong shaking. There might be no dislocation of face-slabs at full reservoir, and the water elevation just above construction joints would induce larger damage.

Sign in / Sign up

Export Citation Format

Share Document