Undrained and drained (?) stress-strain response

2000 ◽  
Vol 37 (5) ◽  
pp. 1126-1130 ◽  
Author(s):  
Y P Vaid ◽  
A Eliadorani
Keyword(s):  
Effective Stress ◽  
Void Ratio ◽  
Effective Strain ◽  
Shear Stiffness ◽  
Stress Path ◽  
Stress Increment ◽  
Stress Strain ◽  
Field Problem ◽  
Deformation Response ◽  
Do So

The deformation response of saturated soils to a total stress increment at the ambient void ratio and effective stress state is shown to be dependent on the direction of the effective strain increment. It is argued that in a given field problem, most soil elements neither deform fully drained nor undrained, but do so partially drained. The degree of partial drainage controls the direction of the effective stress increment and hence the deformation response. Experimental data are presented which demonstrate how shear stiffness changes with the direction of effective stress increment as a function of the ambient effective stress state.Key words: stress-strain, undrained, drained, partially drained, stress path, stiffness.

scholarly journals Stress–Strain Strength Characteristics of Undisturbed Granite Residual Soil Considering Different Patterns of Variation of Mean Effective Stress

2021 ◽  
Vol 11 (4) ◽  
pp. 1874
Author(s):  
Rongjun Shu ◽  
Lingwei Kong ◽  
Bingheng Liu ◽  
Juntao Wang
Keyword(s):  
Effective Stress ◽  
Stress Path ◽  
Strength Characteristics ◽  
Triaxial Tests ◽  
Residual Soil ◽  
Residual Soils ◽  
Stress Strain ◽  
Tropical Regions ◽  
Granite Residual Soil ◽  
Pattern Of Variation

Granite residual soil is one of the most frequently encountered problem soils in tropical regions, whose mechanical behavior heavily depends on the pattern of variation of mean effective stress (p’) during shearing, which can be classified into three categories: increasing-p’, constant-p’, and decreasing-p’. Unfortunately, so far, the stress–strain strength characteristics of granite residual soils have been studied mainly under increasing-p’ stress paths, although it is very likely to encounter stress paths with decreasing p’ in practice, especially in excavation engineering. Moreover, most pertinent research has focused on remolded granite residual soils, whereas undisturbed specimens have not yet received enough attention. In this paper, stress path triaxial tests considering different patterns of variation of mean effective stress were conducted on an undisturbed granite residual soil. Subsequently, a variable termed loading angle was introduced to quantitatively represent stress path. The influences of stress path on the Mohr–Coulomb strength parameters, deformation characteristics, ductility, and shearing stiffness were analyzed, with an emphasis on the role of pattern of variation of mean effective stress. The experimental results show that friction angle of the soil increases while cohesion decreases with the increase in loading angle. The increase in loading angle leads to less volume contraction and smaller failure strain. During shearing, the soil exhibited a less brittle response under stress paths with smaller loading angles. The initial secant shear modulus first decreased and then increased as the loading angle increased, with the minimum shearing stiffness occurring at a certain loading angle lying between 90° and 123.7°.

Stress path effects on the strength behaviour of a layered soil

1980 ◽  
Vol 17 (4) ◽  
pp. 603-607 ◽  
Author(s):  
M. Krishna Murthy ◽  
T. S. Nagaraj ◽  
A. Sridharan
Keyword(s):  
Experimental Investigation ◽  
Effective Stress ◽  
Volume Change ◽  
Stress Path ◽  
Layered Soil ◽  
Shear Behaviour ◽  
Compression Tests ◽  
Stress Strain ◽  
Strain Behaviour ◽  
Stress Parameters

An experimental investigation dealing with the influence of stress path on the shear behaviour of a layered soil prepared in the laboratory is described. Specimens trimmed in vertical and horizontal directions have been sheared under three different stress paths in compression and extension tests. Either in compression or extension, the stress–strain behaviour of the specimens with both orientations was apparently the same, although the volume change behaviour was different. The effective stress parameters C′ and [Formula: see text]′ were found to be unique and independent of the stress path and two principal orientations. However, the values of [Formula: see text]′ in extension tests were 6–7° higher than those in compression tests.

Effect of intermediate principal stress on the deformation response of sand

1996 ◽  
Vol 33 (5) ◽  
pp. 822-828 ◽  
Author(s):  
A Sãyao ◽  
Y P Vaid
Keyword(s):  
Principal Stress ◽  
Hollow Cylinder ◽  
Stress Path ◽  
B Value ◽  
Shear Loading ◽  
Intermediate Principal Stress ◽  
Experimental Program ◽  
Stress Strain ◽  
Deformation Response ◽  
Strain Behaviour

An experimental investigation of the relevance of the intermediate principal stress (σ2) on the deformation response of a sand is presented. The effects of σ2 are conveniently studied through the nondimensional stress parameter b = (σ2 – σ3)/(σ1 – σ3). A series of stress path tests was performed on Ottawa sand specimens in a hollow cylinder torsional shear device. The experimental program includes shear loading at different values of b, and special b tests, in which b was continuously varied at different stress directions. It is shown that the b value may have a significant influence on the stress–strain response of sand, depending on the loading conditions. Key words: hollow cylinder tests, generalized stress paths, sand, stress–strain behaviour, intermediate principal stress.

Stress–strain response of Cold Lake oil sands

1993 ◽  
Vol 30 (2) ◽  
pp. 220-235 ◽  
Author(s):  
R. C. K. Wong ◽  
W. E. Barr ◽  
P. R. Kry
Keyword(s):  
Pore Pressure ◽  
Critical State ◽  
Oil Sands ◽  
Void Ratio ◽  
Stress Path ◽  
Strain Response ◽  
Oil Sand ◽  
Stress Strain ◽  
Sample Disturbance ◽  
Cold Lake

The stress–strain response of Cold Lake oil sands at confining stresses and temperatures up to 18 MPa and 200 °C, respectively, was studied in a triaxial apparatus using 89-mm full diameter cores. Tests that have been performed include conventional triaxial tests such as hydrostatic compression, initial Young's modulus determination, and cyclic drained and undrained compression. Tests involving pore-pressure increase and decrease under constant total stresses were also performed to simulate the stress path encountered in the field during the cyclic steam stimulation process. Treating oil sand as a particulate medium, possible modes of granular interaction were explored for all tests along different stress paths. Four modes of granular interaction were identified: (i) contact elastic deformation, (ii) rolling, (iii) shear dilation, and (iv) crushing. These modes provide a useful framework for explaining the behaviour arising from the effects of variation in void ratio owing to sample disturbance, stress level, stress path, induced anisotropy, and temperature. Other behaviour relating to critical state, localized shear deformation, and load–unload–reload are also examined. Key words : oil sand, stress, strain, void ratio, pore pressure, temperature, mode of granular interaction, critical state.

Stress path and steady state

1990 ◽  
Vol 27 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Y. P. Vaid ◽  
E. K. F. Chung ◽  
R. H. Kuerbis
Keyword(s):  
Steady State ◽  
Effective Stress ◽  
Void Ratio ◽  
Triaxial Compression ◽  
Stress Path ◽  
Stress Space ◽  
Sand Liquefaction ◽  
State Strength ◽  
The Difference ◽  
State Stress

The effect of stress path on the steady state line of a liquefiable sand is investigated. Results from undrained triaxial compression and extension tests on water-deposited sands show that the steady state line of a given sand, though unique in the effective stress space, is not so in the void ratio – effective stress space. The sand is contractive over a much larger range of void ratios in extension than in compression. While a single steady state line emerges for compression loading, extension loading yields several lines, each characteristic to a given deposition void ratio. All these extension lines lie to the left of the compression line in void ratio – effective stress space. Thus at a given void ratio, steady state strength is smaller in extension than in compression, the difference increasing as the sand becomes looser. The implications of the results are discussed in relation to practical design. Key words: sand, liquefaction, steady state, stress path.

Experimental Study on the Time Effect of the Jacked Pile

2013 ◽  
Vol 353-356 ◽  
pp. 125-129
Author(s):  
Rui Cai Wang ◽  
Jian Yong Shi ◽  
Sheng Chen ◽  
Hua Jie Chen
Keyword(s):  
Initial Stress ◽  
Pore Water ◽  
Effective Stress ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Stress Path ◽  
Test Results ◽  
Stress Increment ◽  
Excess Pore Water Pressure ◽  
Triaxial Apparatus

Based on the strain-holding test by using GDS stress path triaxial apparatus, the changes of pore water pressure and stress of soil around the pile were simulated during and after pile jacking. Test results show as follows: excess pore water pressure and effective stress increment increase with strain and initial stress rising at the stage of strain applied. And at the stage of strain holding, effective stress increment increases with rising of strain and initial stress. For the total effective stress increment, the proportion of effective stress increment is large at the stage of strain applied. And at the stage of strain holding, the proportion of effective stress increment is small.

Estimates of effective stress beneath a modern West Antarctic ice stream from till preconsolidation and void ratio

Boreas ◽  
2001 ◽  
Vol 30 (2) ◽  
pp. 101-114 ◽  
Author(s):  
Slawek Tulaczyk, Barclay Kamb, Hermann F.
Keyword(s):  
Effective Stress ◽  
Void Ratio ◽  
West Antarctic ◽  
Ice Stream

Stress–strain pattern–based criterion to assess cyclic shear resistance of soil from laboratory element tests

2016 ◽  
Vol 53 (9) ◽  
pp. 1460-1473 ◽  
Author(s):  
Dharma Wijewickreme ◽  
Achala Soysa
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Shear Stiffness ◽  
Large Strains ◽  
Fundamental Parameter ◽  
Stress Strain ◽  
Cyclic Shear ◽  
Excess Pore Water Pressure ◽  
Excess Pore

The cyclic shear response of soils is commonly examined using undrained (or constant-volume) laboratory element tests conducted using triaxial and direct simple shear (DSS) devices. The cyclic resistance ratio (CRR) from these tests is expressed in terms of the number of cycles of loading to reach unacceptable performance that is defined in terms of the attainment of a certain excess pore-water pressure and (or) strain level. While strain accumulation is generally commensurate with excess pore-water pressure, the definition of unacceptable performance in laboratory tests based purely on cyclic strain criteria is not robust. The shear stiffness is a more fundamental parameter in describing engineering performance than the excess pore-water pressure alone or shear strain alone; so far, no criterion has considered shear stiffness to determine CRR. Data from cyclic DSS tests indicate consistent differences inherent in the patterns between the stress–strain loops at initial and later stages of cyclic loading; instead of relatively “smooth” stress–strain loops in the initial parts of loading, nonsmooth changes in incremental stiffness showing “kinks” are notable in the stress–strain loops at large strains. The point of pattern change in a stress–strain loop provides a meaningful basis to determine the CRR (based on unacceptable performance) in cyclic shear tests.

Closure to “Effective Stress-Strain-Strength Model for Soils”

1976 ◽  
Vol 102 (6) ◽  
pp. 649-650
Author(s):  
Jean-Hervé Prévost ◽  
Kaare Höeg
Keyword(s):  
Effective Stress ◽  
Strength Model ◽  
Stress Strain

A multiaxial stress-strain analysis for proportional cyclic loading

1993 ◽  
Vol 28 (2) ◽  
pp. 125-133 ◽  
Author(s):  
A Navarro ◽  
M W Brown ◽  
K J Miller
Keyword(s):  
Strain Analysis ◽  
Hysteresis Loops ◽  
Strain Curve ◽  
Cyclic Stress ◽  
Strain Hardening Exponent ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Flow Equations ◽  
Deformation Response ◽  
Tubular Specimens

A simplified treatment is presented for the analysis of tubular specimens subject to in-phase tension-torsion loads in the elasto-plastic regime. Use is made of a hardening function readily obtainable from the uniaxial cyclic stress-strain curve and hysteresis loops. Expressions are given for incremental as well as deformation theories of plasticity. The reversals of loading are modelled by referring the flow equations to the point of reversal and calculating distances from the point of reversal using a yield critertion. The method has been used to predict the deformation response of in-phase tests on an En15R steel, and comparisons with experimental data are provided. The material exhibited a non-Masing type behaviour. A power law rule is developed for predicting multiaxial cyclic response from uniaxial data by incorporating a hysteretic strain hardening exponent.

Sign in / Sign up

Export Citation Format

Share Document