Coefficient of earth pressure at rest for sands subjected to vibration

2007 ◽  
Vol 44 (10) ◽  
pp. 1242-1263 ◽  
Author(s):  
Barames Vardhanabhuti ◽  
Gholamreza Mesri
Keyword(s):  
Lake Michigan ◽  
Earth Pressure ◽  
Horizontal Stress ◽  
Vertical Vibration ◽  
Vertical Stress ◽  
Dynamic Changes ◽  
Shearing Resistance ◽  
Interparticle Contacts ◽  
Horizontal Pressure ◽  
Stress Ratios

An oedometer instrumented to measure horizontal pressure was used to examine the behavior of the coefficient of earth pressure at rest, Ko, of clean sands subjected to vertical vibration. Reconstituted specimens of Ottawa, Lake Michigan Beach, and Niigata sands were used in a comprehensive series of tests. The dynamic effort is defined by the ratio of dynamic increase in effective vertical stress to the static effective vertical stress, and frequency and duration of vibration. Dynamic changes in Koare referenced to a series of lines representing the ratio of the increase in effective horizontal stress to the increase in effective vertical stress corresponding to different void ratios or friction angles through the Jaky equation. An increase in Kooccurs when the combination of the initial sand state and dynamic effort results in periodic disengagement of interparticle contacts, producing a periodic decrease in interparticle shearing resistance and thus a periodic fluidization of the sand. The highest values of [Ko]maxas well as the lowest values of eminwere obtained with dynamic stress ratios equal to or greater than 3–4. Vibration of overconsolidated sands results in an initial Kodrop that increases with previbration density and overconsolidation ratio. Thereafter, the behavior of Koand void ratio with vibration depend on the potential for fluidization.

Field Performance and Analysis of 3-m-Diameter Induced Trench Culvert under a 19.4-m Soil Cover

2008 ◽  
Vol 2045 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Bethanie A. Parker ◽  
Rodney P. McAffee ◽  
Arun J. Valsangkar
Keyword(s):  
Pressure Distribution ◽  
Earth Pressure ◽  
Field Performance ◽  
Overburden Pressure ◽  
Vertical Pressure ◽  
Earth Pressures ◽  
Design Loads ◽  
Horizontal Pressure ◽  
Two Stages

An induced trench installation was instrumented to monitor earth pressures and settlements during construction. Some of the unique features of this case study are as follows: (a) both contact and earth pressure cells were used; (b) part of the culvert is under a new embankment and part was installed in a wide trench within an existing embankment; (c) a large stockpile was temporarily placed over the induced trench; and (d) the compressible material was placed in two stages. The maximum vertical pressure measured in the field at the crown of the culvert was 0.24 times the overburden pressure. The maximum horizontal pressure measured on the side of the culvert at the springline was 0.45 times the overburden pressure. The column of soil directly above the compressible zone settled approximately 40% more than did the adjacent fill. The field results at the crown and springline compared reasonably with those observed with numerical modeling. However, the overall pressure distribution on the pipe was expected to be nonuniform, the average vertical pressure calculated by using numerical analysis on top of the culvert over its full width was 0.61 times the overburden pressure, and the average horizontal pressure calculated on the side of the culvert over its full height was 0.44 times the overburden pressure. When the full pressure distribution on the pipe is considered, the recommended design loads from the Marston–Spangler theory slightly underpredict the maximum loads, and the vertical loads control the design.

scholarly journals Stress Distribution in a Cohesionless Backfill Poured in a Silo

2014 ◽  
Vol 8 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Li Li ◽  
Jonathan D. Aubertin ◽  
Jean-Sébastien Dubé
Keyword(s):  
Soil Structure ◽  
Earth Pressure ◽  
Horizontal Stress ◽  
Density Variation ◽  
Direction Parallel ◽  
Rest State ◽  
Drop Mass ◽  
Drop Tests ◽  
Series Of Experiments ◽  
Infrastructure Rehabilitation

The field of infrastructure rehabilitation and development requires a better understanding of soil-structure interactions. The interaction behaviour between soil and structures has mostly been investigated through theoretical and/or numerical analysis. This paper presents a series of experiments performed on an intermediate-scale physical model made of an instrumented silo. In contrast to most reported laboratory tests, both the horizontal and vertical stresses were monitored during backfilling operations realised by wild pouring. Drop tests were performed to investigate the density variation with respect to the drop (or falling) height of the soil, which were introduced in the pressure interpretation. The results showed that horizontal stress in the direction parallel to the pouring plane is larger than that perpendicular to the pouring plane. Apparently, the vertical stress is well-described using the arching solution by considering the backfill in an active state, whereas the horizontal stress perpendicular to the pouring plane is better described with the arching solution by considering the backfill in an at-rest state. An estimate of the earth pressure coefficients based on the measured vertical and horizontal stresses indicates, however, that the backfill was closer to an at-rest state in the direction perpendicular to the pouring plane, whereas in the direction parallel to the pouring plane, it was in a state between at-rest and passive. These results indicate that it is important to measure both the horizontal and vertical stresses to obtain a whole picture of the state of the backfill. The results showed also that the horizontal stresses can be larger than those calculated by the overburden solution, probably due to dynamic loading by drop mass during the filling operation and stress lock.

scholarly journals In Situ Stress and Stress Regime in the Onshore Part of the Northeast Java Basin

2021 ◽  
Vol 44 (2) ◽  
pp. 95-105
Author(s):  
Agus M. Ramdhan
Keyword(s):  
Petroleum Industry ◽  
Horizontal Stress ◽  
In Situ Stress ◽  
Vertical Stress ◽  
Stress Regime ◽  
Severe Erosion ◽  
Tectonically Active ◽  
Minimum Horizontal Stress ◽  
Maximum Horizontal Stress

In situ stress is importance in the petroleum industry because it will significantly enhance our understanding of present-day deformation in a sedimentary basin. The Northeast Java Basin is an example of a tectonically active basin in Indonesia. However, the in situ stress in this basin is still little known. This study attempts to analyze the regional in situ stress (i.e., vertical stress, minimum and maximum horizontal stresses) magnitude and orientation, and stress regime in the onshore part of the Northeast Java Basin based on twelve wells data, consist of density log, direct/indirect pressure test, and leak-off test (LOT) data. The magnitude of vertical (  and minimum horizontal (  stresses were determined using density log and LOT data, respectively. Meanwhile, the orientation of maximum horizontal stress  (  was determined using image log data, while its magnitude was determined based on pore pressure, mudweight, and the vertical and minimum horizontal stresses. The stress regime was simply analyzed based on the magnitude of in situ stress using Anderson’s faulting theory. The results show that the vertical stress ( ) in wells that experienced less erosion can be determined using the following equation: , where  is in psi, and z is in ft. However, wells that experienced severe erosion have vertical stress gradients higher than one psi/ft ( . The minimum horizontal stress ( ) in the hydrostatic zone can be estimated as, while in the overpressured zone, . The maximum horizontal stress ( ) in the shallow and deep hydrostatic zones can be estimated using equations: and , respectively. While in the overpressured zone, . The orientation of  is ~NE-SW, with a strike-slip faulting stress regime.

The Pressure Ratio in the Theory of Bin Pressures

1979 ◽  
Vol 46 (3) ◽  
pp. 524-528 ◽  
Author(s):  
S. C. Cowin
Keyword(s):  
Granular Material ◽  
Bulk Density ◽  
Pressure Ratio ◽  
Vertical Wall ◽  
Yield Condition ◽  
Horizontal Stress ◽  
Vertical Stress ◽  
Linear Functions ◽  
Cross Sectional ◽  
Cross Sectional Average

The pressure ratio K0 is assumed to be a constant in the theory developed by Janssen for determining the pressures imparted by a granular material to its container. Recently it was shown that K0 can be defined less restrictively as the ratio of the perimeter average of the horizontal stress acting on the vertical wall of the container to the cross-sectional average of the vertical stress in the granular material at the same depth in the container. Three results concerning K0 are presented in this paper. First, it is shown that the essential result of Janssen, namely that the vertical and horizontal stresses have a constant bound at great depths, also holds in the case when the bulk density and the pressure, ratio are bounded by linear functions of the average vertical stress. Second, it is shown that a formula relating K0 to the Poisson’s ratio of the granular material is not correct, in general. Third, bounds on K0 are obtained using the Mohr-Coulomb yield condition for the granular material.

Numerical Analysis of Widened Embankments with Geogrid Reinforcement

2012 ◽  
Vol 256-259 ◽  
pp. 2004-2008
Author(s):  
Min Yong Chen ◽  
Yu Liu ◽  
Hai Li Shi ◽  
Rui Chen ◽  
Bing Xiang Yuan
Keyword(s):  
Shear Stress ◽  
Numerical Analysis ◽  
Horizontal Stress ◽  
Vertical Stress ◽  
Stress Redistribution ◽  
Small Decrease ◽  
Geogrid Reinforcement ◽  
Layer Number

The mechanism of geogrid reinforcement in an embankment widening project was investigated in this study using numerical analysis. It was found that the geogrid reinforcement mainly affects the new embankment by decreasing settlement slightly and restraining the horizontal outward displacement effectively. This effect of geogrid reinforcement on embankment deformations is due to the stress redistribution in the new embankment and in the subsoil caused by geogrid reinforcement. The inclusion of geogrid reinforcement produces a small decrease in vertical stress in the new embankment and leads to a relatively larger increase in horizontal stress in the subsoil, thereby decreasing the shear stress of the subsoil. The effect of geogrid reinforcement on the new embankment and subsoil increases with the increasing geogrid layer number.

The Research on Earth Pressure behind Inclined Retaining Wall Considering Arching Effects

2013 ◽  
Vol 790 ◽  
pp. 410-413
Author(s):  
Jian Ming Zhu ◽  
Qi Zhao
Keyword(s):  
Stress State ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Vertical Stress ◽  
Soil Arching ◽  
Active Pressure ◽  
Passive Pressure ◽  
The Earth ◽  
Two Factors

The earth pressure behind inclined wall considering the soil arching effects which was decided by two factors, the coefficient and average vertical stress, was necessary to research. Based on the analysis of stress state behind the retaining wall, the unified solution of active pressure and passive pressure was derived and was used to calculate both the magnitude and point of application. According to examples, as the angle of inclined retaining wall increasing which was signifying by , the arching effects would be also increasing which the soil was in the passive limit and be falling which the soil was in the active limit.

The coefficient of earth pressure at rest

1993 ◽  
Vol 30 (4) ◽  
pp. 647-666 ◽  
Author(s):  
G. Mesri ◽  
T.M. Hayat
Keyword(s):  
Soft Clay ◽  
Earth Pressure ◽  
Stress Path ◽  
Vertical Stress ◽  
Deformation Condition ◽  
Granular Soils ◽  
Empirical Equations ◽  
Angle Of Internal Friction ◽  
Secondary Compression ◽  
Clay Deposits

Laboratory experiments on undisturbed specimens of a large number of soft clay deposits, as well as previous measurements on clays and granular soils, were used to examine and explain the magnitude and behavior of the coefficient of earth pressure at rest, K0: (i) after sedimentation – primary consolidation, (ii) during secondary-compression aging, (iii) after active or passive preshearing away from the laterally constrained condition, (iv) during a decrease in effective vertical stress, and (v) during an increase in effective vertical stress in the recompression or compression range, in terms of [Formula: see text], the slope of the effective horizontal [Formula: see text] versus effective vertical[Formula: see text] stress path. The behavior of K0 is explained using the concept of mobilized angle of friction in laterally constrained deformation condition. The Jaky equation provides, in terms of the angle of internal friction, a good estimate of K0 of sedimented, normally consolidated young clays and granular soils, as well as of [Formula: see text] of presheared clays and sands, and of densified granular soils that are subjected to laterally constrained compression from [Formula: see text]. Empirical equations provide reasonable estimates of K0 for clays and granular soils after secondary-compression aging, after preconsolidation by unloading, and for soft clay deposits that display a preconsolidation pressure [Formula: see text] greater than in situ effective vertical stress [Formula: see text]. Proposed empirical equations and methods successfully predict K0 of presheared clays. Key words: coefficient of earth pressure at rest, soft clays, granular soils, presheared soils, sampling and laboratory testing.

scholarly journals Numerical Simulation of Empty-Hole Effect during Parallel-Hole Cutting under Different In Situ Stress Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhengyu Wu ◽  
Dayou Luo ◽  
Feng Chen ◽  
Wulin Huang
Keyword(s):  
Stress Field ◽  
Horizontal Stress ◽  
In Situ Stress ◽  
Vertical Stress ◽  
Stress Conditions ◽  
Deep Mining ◽  
In Situ Stress Field ◽  
Hole Effect ◽  
Parallel Hole

With the progress of deep mining in mine exploitation, the effect of the in situ stress field plays a more and more significant and crucial role in rock blasting. To uncover the impact of in situ stress field on empty-hole effect during parallel-hole cutting, the distribution and the trend of changes in dynamic stress around empty hole during blasting under different in situ stress conditions are simulated based on the basic model for parallel-hole cutting using 3D finite element analysis software ANSYS/LS-DYNA and implicit-explicit analysis method. Subsequently, the law of variation in the empty-hole effect under different in situ stress conditions is determined, and the effects of horizontal and vertical stress fields are analyzed in detail. The simulation results show that the overall increase in in situ stress can facilitate compressive failure and inhibit tensile failure in the rock mass around an empty hole during blasting. When empty holes are arranged horizontally, the effect of the vertical stress field is consistent with that of the in situ stress field, while the effect of the horizontal stress field is opposite to that of the in situ stress field. With the increased stress, the inhibitive effect of the vertical stress field on tensile stress around an empty hole is remarkably stronger than that of the horizontal stress field. Finally, the numerically simulated results are verified by the theoretical calculation. This study can provide new insight and a simple but accurate numerical simulation method to investigate how the in situ stress field affects the empty-hole effect, especially in deep mining.

Hydraulic fracture-height containment by permeable weak bedding interfaces

Geophysics ◽  
2018 ◽  
Vol 83 (3) ◽  
pp. MR137-MR152 ◽  
Author(s):  
Xiaowei Weng ◽  
Dimitry Chuprakov ◽  
Olga Kresse ◽  
Romain Prioul ◽  
Haotian Wang
Keyword(s):  
Coefficient Of Friction ◽  
Hydraulic Fracture ◽  
Shear Failure ◽  
Mechanistic Model ◽  
Bedding Plane ◽  
Horizontal Stress ◽  
Height Growth ◽  
Vertical Stress ◽  
Weak Interface ◽  
Minimum Horizontal Stress

In laminated formations, the vertical height growth of a hydraulic fracture can be strongly influenced by the interaction of the fracture tip with the bedding interfaces it crosses. A weak interface may fail in shear and then slip, depending on the strength and frictional properties, the effective vertical stress at the interface, and the net pressure. Shear failure and slippage at the interface can retard the height growth or even stop it completely. A 2D analytical model called the FracT model has been developed that examines the shear slippage along the bedding interface adjacent to the fracture tip and the resulting blunting of the fracture tip at the interface, as well as the stress condition on the face opposite from the hydraulic fracture tip for possible fracture nucleation that leads to fracture crossing. The growth of the shear slippage along the interface with time is coupled with the fluid flow into the permeable interface. A parametric study has been carried out to investigate the key formation parameters that influence the crossing/arrest of the fracture at the bedding interface and the shear slippage and depth of fluid penetration into the interface. The study suggests that the interfacial coefficient of friction and the ratio of the vertical to minimum horizontal stress are two of the most influential parameters governing fracture arrest by a weak interface. For the fracture tip to be arrested at the interface, the vertical stress acting on the interface must be close to the minimum horizontal stress or the interfacial coefficient of friction must be very small. The FracT model has also been integrated into a pseudo-3D-based complex hydraulic fracture model. This quantitative mechanistic model that incorporates a bedding-plane slip-driven mechanism is a necessary step to understand and bridge the characterization (sonic) and monitoring (microseismic) observations.

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