Log in

Relevant bibliographies by topics / Undrained Condition / Journal articles

Journal articles on the topic 'Undrained Condition'

To see the other types of publications on this topic, follow the link: Undrained Condition.

Author: Grafiati

Published: 14 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Undrained Condition.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Tang, Bin, Zhe Zeng, and Yan Xia Gong. "The Empirical Formula Research and the Test for the Soft Clay Coupled Consolidation and Creep Character in Different Drainage Conditions." Applied Mechanics and Materials 90-93 (September 2011): 1819–23. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.1819.

Full text

Abstract:

Abstract: Conducted a series of triaixl coupled consolidation and creep tests ,and researched the coupled consolidation and creep character for the typical soft clay in Wuhan region in different drainage conditions.The following conclusions are got from analysing the stress、strain and time relationship curves in different conditions:(1)The consolidation drainage condition is very important in the soil consolidation creep deformation.When the stress is low,the deformation amount in the consolidation undrained condition is much smaller than that in the consolidation drained condition;with the increasing of the stress,the viscoplasticity will appear,and the deformation speed in the undrained condition exceeded that in the drained condition;when the stress increases to some point,the deformation amount in the undrained condition will exceed that in the drained condition finally.(2)The consolidation creep deformation rule for the typical soft clay in Wuhan region in different drainage conditions can be expressed by empirical formula.

APA, Harvard, Vancouver, ISO, and other styles

2

Dołżyk-Szypcio, Katarzyna. "Stress-strain behaviour of Toyoura sand in undrained triaxial compression." E3S Web of Conferences 92 (2019): 15010. http://dx.doi.org/10.1051/e3sconf/20199215010.

Full text

Abstract:

The stress-plastic dilatancy relationship for Toyoura sand sheared under undrained triaxial conditions was analysed by use of Frictional State Theory. Under undrained conditions, plastic strain increments are counterbalanced by elastic strain increments. The linear stress ratio-plastic dilatancy relationships at different stages of sand shear were obtained by assuming that Poisson's ratio is a function of shear strain. Contrary to a drained condition, natural state parameter values are not special for characteristic points of sand behaviour under undrained conditions.

APA, Harvard, Vancouver, ISO, and other styles

3

Hsieh, P. G., and C. Y. Ou. "Analysis of Nonlinear Stress and Strain in Clay under the Undrained Condition." Journal of Mechanics 27, no. 2 (June 2011): 201–13. http://dx.doi.org/10.1017/jmech.2011.24.

Full text

Abstract:

ABSTRACTThough the total stress undrained analysis approach in geotechnical engineering is widely utilized by practicing engineers, it has some intrinsic imperfections that cause the obtained parameters to have unavoidable empirical correlations. In this study, an undrained soft clay model is developed, which overcomes the imperfections of the conventional total stress undrained approach. In addition, the high soil stiffness at small strain and the concept of yield surface are employed to realistically simulate actual soil behavior. The model parameters can be obtainable directly from conventional laboratory tests. The model is validated through different laboratory stress path tests and strength tests in this paper.

APA, Harvard, Vancouver, ISO, and other styles

4

Leong, W. K., and J. Chu. "Effect of undrained creep on instability behaviour of loose sand." Canadian Geotechnical Journal 39, no. 6 (December 1, 2002): 1399–405. http://dx.doi.org/10.1139/t02-076.

Full text

Abstract:

Prefailure instability in the form of a runway deformation can occur for loose sand under undrained conditions. The effect of creep on the instability behaviour of loose sand is studied experimentally in this note. Previous studies have established that instability can only occur when the stress state is above the instability line. However, if creep is allowed to develop under undrained conditions, instability can still possibly occur even when the stress state at which creep develops is below the instability line. A boundary that specifies the condition in which instability may be induced by undrained creep is determined based on the experimental data.Key words: laboratory test, liquefaction, sands, shear strength.

APA, Harvard, Vancouver, ISO, and other styles

5

ISHIZAKI, Hitoshi. "Deformation analysis of composite groud under undrained condition." Doboku Gakkai Ronbunshu, no. 448 (1992): 53–62. http://dx.doi.org/10.2208/jscej.1992.448_53.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Fattah, M. Y., F. A. Salman, Y. J. Al-Shakarchi, and A. M. Raheem. "Coupled pile-soil interaction analysis in undrained condition." Journal of Central South University 20, no. 5 (May 2013): 1376–83. http://dx.doi.org/10.1007/s11771-013-1625-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Nakata, Yukio, Tetsuya Tashita, Hiromu Chibana, and Kenji Matsukata. "Effect of drainage and saturation on undrained shear strength for compacted sandy soils." E3S Web of Conferences 92 (2019): 07003. http://dx.doi.org/10.1051/e3sconf/20199207003.

Full text

Abstract:

Collapses of embankments have occurred due to heavy rainfall. It is very important to understand the strength properties under various unsaturated, partially saturated and fully saturated conditions of compacted materials. So, a series of unsaturated and saturated triaxial compression tests for compacted soils have been conducted to understand the effects of drainage and saturation on undrained strength. Soil samples were collected from several road embankments to carry out the experiments. The undrained (CU) strength of compacted material decreased with increase in the degree of saturation. Especially, the strength decreased from partially saturated condition to fully saturated condition was remarkable. The decrease of the materials with volume contractive behaviour was appeared clearly.

APA, Harvard, Vancouver, ISO, and other styles

8

Sun, Wen Jing, De An Sun, and Jin Yi Zhang. "Undrained Behavior of Unsaturated Bentonite-Sand Mixture." Advanced Materials Research 446-449 (January 2012): 1454–57. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.1454.

Full text

Abstract:

The strength, deformation and hydro-mechanical behaviours of a compacted unsaturated Gaomiaozi bentonite-sand mixture under undrained condition are studied by conducting a series of isotropic compression tests and triaxial shear tests under constant water content. During undrained isotropic compression testing, void ratio and suction decrease while degree of saturation increases. The stress-strain relations are obtained from undrained triaxial shear tests. The volume contraction and lateral expansion can be observed. The suction decreases with increasing shearing. The net confining pressure and initial dry density affect the initial rigidity, undrained shear strength, volumetric deformation and hydro-mechanical behaviour.

APA, Harvard, Vancouver, ISO, and other styles

9

Hsu, Shih Tsung, Wen Chi Hu, Yu Heng Lin, and Zhuo Ling. "A Characteristic and a Precisely Constitutive Model for Undrained Clay." Materials Science Forum 975 (January 2020): 203–7. http://dx.doi.org/10.4028/www.scientific.net/msf.975.203.

Full text

Abstract:

Constitutive models for soils are usually adopted in numerical method to analyze the behavior of geotechnical structures. This study performs a series of consolidated-undrained triaxial tests to establish the stress-strain curve of clay. A constitutive model that considers continuous strain hardening-softening is proposed based on the results of triaxial tests. Triaxial test results reveal that undrained shear strength linearly increases with an increase in consolidated pressure , the normalized undrained shear strength is about 0.52 not only for this study but also for the other two cases around Taipei Basin. Due to undrained condition, an associated flow rule between plastic strain increment and stress tensor is adopted. As accumulative plastic strain or/and consolidated pressure change, the mobilized undrained shear strength also changes. All parameters needed for the proposed model can be expressed as a function of undrained shear strength Su, The mobilized undrained shear strength for the proposed model during strain hardening-softening can be in term of accumulative plastic strain. This model can calculate the stress-strain curves of clayed soils accurately.

APA, Harvard, Vancouver, ISO, and other styles

10

Li, Xuefeng, Wendong Xu, Lei Chang, and Wenwei Yang. "Shear Behaviour of Aeolian Sand with Different Density and Confining Pressure." Applied Sciences 12, no. 6 (March 16, 2022): 3020. http://dx.doi.org/10.3390/app12063020.

Full text

Abstract:

Different from the other roadbed material, the unique mechanical properties of aeolian sand bring great difficulties to the construction and maintenance of desert highways. However, the main attention was usually paid to the engineering properties of aeolian sand, such as collapsibility, strong permeability, and poor gradation. To investigate the shear behaviour of aeolian sand under different engineering conditions, the drained and undrained tests were performed on aeolian sand with relatively large range of density and confining pressure. Under this condition, both the drained and undrained tests tend to the same critical state line, and the shear behaviour of aeolian sand is directly dependent on its density. Under the undrained condition, the q-ε1 curves and the effective stress paths in triaxial stress space exhibit four types of undrained shear behaviour, such as flow, limited flow, strain hardening, and strain softening. Meanwhile all the specimens exhibit three types of failure, such as flow slip, bulging failure, and shear bands. In the q-p’ plane, the analogous drained and undrained stress paths can be followed by aeolian sand with same initial relative density but different confining pressures, and there are two critical state lines due to the generation of shear bands for dense sand. In addition, the critical state lines in e-lnp’ plane decrease with increasing initial relative density Dr, that is, the material constant eᴦ decreases with increasing Dr, and the λ is also not constant but decreases with the increase in Dr. The results suggest that the strength behaviours of aeolian sand can be fitted by a straight line considering relative density and confining pressure and that two empirical formulas are established to describe this feature.

APA, Harvard, Vancouver, ISO, and other styles

11

Hong, Jung Hwa, and Young Hwan Park. "Development of Pore Pressure Measurement System in Lacunocanalicular Network of Trabeculae Using MEMS Based Micro-Pressure Transducer." Key Engineering Materials 345-346 (August 2007): 1157–60. http://dx.doi.org/10.4028/www.scientific.net/kem.345-346.1157.

Full text

Abstract:

Experimental measurement of pore pressure generation in lacunocanalicular network of trabeculae is never measured, although the characteristics could be important for bone remodeling. In this study, the pore pressure generation in micro-trabecular specimens within the elastic range was measured in vitro using a specially designed micro-experimental setup and a MEMS based micro-pressure transducer. Then, a quasi-static loading (9㎛/min) was applied up to the strain of 0.4 % with measuring pore pressure generations in the undrained and drained conditions. 49.2 ± 4.45 KPa of pore pressure generation at the 0.4% strain was found in the undrained condition. In contrast, no pore pressure generation was measured in the drained condition. The result could let us know the amount of a possible maximum pore pressure generation in lacunocanalicular network of trabeculae within the elastic range.

APA, Harvard, Vancouver, ISO, and other styles

12

Fakharian, Kazem, Farzad Kaviani Hamedani, Iman Parandian, and Morteza Jabbarpour Aghdam. "Investigation of fabric evolution using bidirectional shear wave velocity measurements." E3S Web of Conferences 92 (2019): 03008. http://dx.doi.org/10.1051/e3sconf/20199203008.

Full text

Abstract:

In order to characterise fabric evolution, continuous bidirectional shear wave velocity measurements are performed in vertical and horizontal directions (V&H) on triaxial soil specimens during shearing in which two horizontal piezo-electrics were mounted on samples using a new measurement technique. The specimens are prepared by wet tamping method and then subjected to strain-controlled compressional shearing under drained and undrained conditions. The shear wave velocities of all drained specimens initially increased as the loading commenced and then converged to a unique state in both horizontal and vertical directions. The shear wave velocity of undrained specimens on the other hand, for both horizontal and vertical directions initially decreased due to the rising of the excess pore water pressure and then gradually approached a unique shear wave velocity like drained specimens. The fabric condition or stiffness in V&H directions of all the examined drained and undrained specimens at critical state are found to be unique.

APA, Harvard, Vancouver, ISO, and other styles

13

Ma'ruf, M. F., K. Suzuki, M. Oda, and M. Yoshimine. "Normalized plastic work of sand under undrained monotonic loading condition." Journal of applied mechanics 7 (2004): 57–64. http://dx.doi.org/10.2208/journalam.7.57.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Uchaipichat, Anuchit. "Temperature and Suction Effects on Slope Stability under Undrained Condition." Applied Mechanics and Materials 858 (November 2016): 98–103. http://dx.doi.org/10.4028/www.scientific.net/amm.858.98.

Full text

Abstract:

In this paper, the variation of safety factor of unsaturated soil slope with temperature and matric suction was simulated. The simulation was performed using modified ordinary method of slices for unsaturated soil slope including temperature and suction effects. The expression for factor of safety of unsaturated soil slope at elevated temperature under undrained condition was derived. The ranges of temperature and suction in simulation were 25 to 60 degree Celsius and 0 to 100 kPa, respectively. The simulation was performed using soil parameters presented in literature. The simulation results shows the variation in factor of safety of soils slope with matric suction and temperature. The factor of safety of soil slope with circular failure surface increased with increasing matric suction for all values of temperature but decreased with increasing temperature for all values of matric suction.

APA, Harvard, Vancouver, ISO, and other styles

15

O’Kelly, B. C., R. B. J. Brinkgreve, and V. Sivakumar. "Pullout resistance of granular anchors in clay for undrained condition." Soils and Foundations 54, no. 6 (December 2014): 1145–58. http://dx.doi.org/10.1016/j.sandf.2014.11.009.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Ma, Shuqi, and Marte Gutierrez. "Coupled Damage-Plasticity Modelling of Saturated Shale under Undrained Condition." KSCE Journal of Civil Engineering 25, no. 1 (November 11, 2020): 316–25. http://dx.doi.org/10.1007/s12205-020-1303-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Chang, Ming-Fang, Cee Ing Teh, and LaiFa Cao. "Critical state strength parameters of saturated clays from the modified Cam clay model." Canadian Geotechnical Journal 36, no. 5 (November 23, 1999): 876–90. http://dx.doi.org/10.1139/t99-050.

Full text

Abstract:

The evaluation of critical state strength parameters is important, especially with the introduction of limit state design. The modified Cam clay (MCC) model is often used, but it is suitable mainly for evaluating the critical state strength parameters from triaxial compression tests on isotropically consolidated soils. The initial stress condition of a natural soil is usually anisotropic, and the stress paths imposed by external loading could deviate from that of a simple triaxial compression. The use of MCC in practice deserves careful consideration. This paper describes a proposed extension of the MCC model for the evaluation of critical state strength parameters from undrained triaxial and plane strain tests on anisotropically consolidated clays. Using Lade's failure criterion and the plastic potential of MCC, a generalized yield surface is determined and the relationships between the critical state internal friction angles from various triaxial and plane strain tests are obtained. By relating the isotropic overconsolidation ratio to the conventional overconsolidation ratio (OCR), a procedure is suggested for the prediction of critical state undrained shear strength (su) for clays. The undrained strength normalized by the preconsolidation pressure is not a constant but a function of the angle of internal friction and the OCR. For overconsolidated clay, the predicted undrained strength ratio (su/σVO) for the triaxial compression condition is larger than that for the plane strain compression condition. Comparisons of predicted results with published data indicate that the procedure is applicable to various compression tests on normally and lightly to moderately overconsolidated clays. Key words: stress anisotropy, clay, constitutive model, critical state, laboratory test, shear strength parameters.

APA, Harvard, Vancouver, ISO, and other styles

18

Sheahan, Thomas C. "Interpretation of undrained creep tests in terms of effective stresses." Canadian Geotechnical Journal 32, no. 2 (April 1, 1995): 373–79. http://dx.doi.org/10.1139/t95-038.

Full text

Abstract:

The paper provides an effective stress-based interpretation technique for undrained creep behavior in cohesive soils. This technique could ultimately be used to predict whether a particular applied shear stress level will lead to failure or creep rupture. During the primary phase of undrained creep at constant shear stress, the soil's strain rate decreases, which in turn leads to a decrease in the undrained shear strength. However, it has been shown for a number of soils that a minimum undrained strength, or upper yield strength (suy), is eventually reached regardless of further strain rate decreases. It has been postulated that this phenomenon is part of a time-dependent behavior framework in which the yield locus shrinks with decreasing strain rate until some limiting surface, the static yield surface (SYS), is reached. Such a surface has been the basis for a number of constitutive models in which it represents the inviscid, or rate independent, behavior. The peak shear stress on the SYS corresponds to suy. Data from previous experimental programs are presented to show the existence of the surface and its role in undrained creep behavior. Undrained creep shear stress levels above suy lead to creep rupture on the failure envelope; stress levels below suy cause creep to the SYS, where the stress state apparently stabilizes without failure. The value of suy can be used in a number of analyses in creep susceptible soils, and the static yield condition can be used in the field to determine whether measured pore pressures are exceeding predicted nonrupture levels. A method is proposed for simple determination of the SYS using constant strain rate undrained shear tests. Key words : clays, consolidated-undrained tests, creep, rate effects, rheology, shear strength.

APA, Harvard, Vancouver, ISO, and other styles

19

Wu, Shengshen, Annan Zhou, Jie Li, Jayantha Kodikara, and Wen-Chieh Cheng. "Hydromechanical behaviour of overconsolidated unsaturated soil in undrained conditions." Canadian Geotechnical Journal 56, no. 11 (November 2019): 1609–21. http://dx.doi.org/10.1139/cgj-2018-0323.

Full text

Abstract:

Hydromechanical behaviour of an unsaturated silt with various suctions and different overconsolidated ratios (OCRs) was investigated through a series of undrained triaxial tests (constant water contents, CW). All the samples were prepared from the slurry state. Different OCRs (= 1, 2, 4, and 8 in net stress) were achieved by unloading the samples to 400, 200, 100, and 50 kPa from an initial confining net pressure of 400 kPa. Then the samples were dried to various suctions (0, 100, 200, 300, and 400 kPa). Unsaturated samples with different OCRs were then sheared at CW conditions following the conventional triaxial compression (CTC) paths. Full hydromechanical responses including the changes in deviator stress, stress ratio, volumetric strain, suction, and degree of saturation with axial strain were monitored and are presented in this paper. Some key findings include (i) the critical state for unsaturated soils with different OCRs can be well defined by Bishop’s effective stress; (ii) the peak strength in Bishop’s effective stress increases with increase of OCR, but decreases with increase of suction in the undrained condition; and (iii) the volume change of unsaturated soils in undrained conditions is related to OCRs and the volume of pore air.

APA, Harvard, Vancouver, ISO, and other styles

20

Silvestri, V. "On the determination of the stress-strain curve of clay from the undrained plane-strain expansion of hollow cylinders: a long-forgotten method." Canadian Geotechnical Journal 35, no. 2 (April 1, 1998): 360–63. http://dx.doi.org/10.1139/t97-084.

Full text

Abstract:

This paper presents the method to obtain the shear stress curve of clay from the undrained plane-strain expansion of hollow cylinder triaxial tests. No prior knowledge of the constitutive properties of the material is required. The theory also indicates that when the outer radius of the cylinder is very large compared with the inner radius, the equation used to interpret pressuremeter tests in clay is recovered.Key words: hollow cylinder, expansion tests, clays, plane strain, undrained condition, shear stress curve.

APA, Harvard, Vancouver, ISO, and other styles

21

Xu, Bin Bin, Toshihiro Noda, and Kentaro Nakai. "Realization of Uniform Deformation under Three-Dimensional Condition Based on Soil-Water Coupled Analysis Considering Inertia Forces." Applied Mechanics and Materials 638-640 (September 2014): 530–33. http://dx.doi.org/10.4028/www.scientific.net/amm.638-640.530.

Full text

Abstract:

In the paper, based on soil-water coupled finite deformation analysis, theoretical considerations and numerical calculations were carried out under undrained three-dimensional condition in order to reproduce a uniform deformation field. At first, a theoretical consideration was assumed to realize a uniform deformation for a saturated soil, according to which the initial velocity and acceleration in both vertical and circumferential directions should be applied to each node to remove the influence of inertia effect. This first theoretical analysis is useful and can guide the numerical calculation. Next, the paper realized a uniform deformation of a three-dimensional cylinder specimen under undrained boundary conditions using the soil-water coupled analysis in which the SYS Cam-clay model is employed as the constitutive model for soil skeleton. The numerical results show that without the inertia forces there is no localized deformation in the specimen.

APA, Harvard, Vancouver, ISO, and other styles

22

Norris, G., R. Madhu, M. Ashour, and R. Valceschini. "Peak Undrained Resistance of Loose Sands." Transportation Research Record: Journal of the Transportation Research Board 1569, no. 1 (January 1997): 65–76. http://dx.doi.org/10.3141/1569-08.

Full text

Abstract:

The peak undrained resistance (σ d,upeak) of a loose sand during liquefaction under monotonic loading does not necessarily occur on or near the Mohr Coulomb failure envelope. Instead, it occurs as that combination or product of a decreasing effective confining pressure ([Formula: see text]) and an increasing stress level ( SL). The condition in which this product is a maximum occurs at a particular point on a plot of the deviator stress (σ d) versus volumetric strain (ε v) as assessed from a drained triaxial test. A method is presented whereby a single drained test with volume change measurement can be used to assess this undrained peak. This is a refinement of a more complete effective stress method of liquefaction analysis that requires only drained triaxial testing.

APA, Harvard, Vancouver, ISO, and other styles

23

Yu, Fangwei, and Ikuo Towhata. "Particle breakage and its influence on soil behavior under undrained condition." Japanese Geotechnical Society Special Publication 2, no. 9 (2016): 386–90. http://dx.doi.org/10.3208/jgssp.jpn-020.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Liu, Xin, Yuchuan Wang, and Boo Hyun Nam. "Characterizing undrained shear behavior of loess subjected to K loading condition." Engineering Geology 302 (June 2022): 106634. http://dx.doi.org/10.1016/j.enggeo.2022.106634.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Chen, Rong‐Her, and Jiann‐Jyh Wang. "A constitutive model for saturated compacted soils under undrained shear condition." Journal of the Chinese Institute of Engineers 10, no. 6 (September 1987): 639–46. http://dx.doi.org/10.1080/02533839.1987.9677022.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Yimsiri, Siam, Wanwarang Ratananikom, Fumihiko Fukuda, and Suched Likitlersuang. "Undrained strength-deformation characteristics of Bangkok Clay under general stress condition." Geomechanics and Engineering 5, no. 5 (October 25, 2013): 419–45. http://dx.doi.org/10.12989/gae.2013.5.5.419.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Wei, Jian-Guang, and Chuan-Liang Yan. "Borehole stability analysis in oil and gas drilling in undrained condition." Geomechanics and Engineering 7, no. 5 (November 25, 2014): 553–67. http://dx.doi.org/10.12989/gae.2014.7.5.553.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Osinov, Vladimir A. "Sufficient conditions for hyperbolicity and consistency of the dynamic equations for fluid-saturated solids." Archive of Applied Mechanics 91, no. 6 (March 8, 2021): 2569–79. http://dx.doi.org/10.1007/s00419-021-01904-6.

Full text

Abstract:

AbstractPrevious studies showed that the dynamic equations for a porous fluid-saturated solid may lose hyperbolicity and thus render the boundary-value problem ill-posed while the equations for the same but dry solid remain hyperbolic. This paper presents sufficient conditions for hyperbolicity in both dry and saturated states. Fluid-saturated solids are described by two different systems of equations depending on whether the permeability is zero or nonzero (locally undrained and drained conditions, respectively). The paper also introduces a notion of wave speed consistency between the two systems as a necessary condition which must be satisfied in order for the solution in the locally drained case to tend to the undrained solution as the permeability tends to zero. It is shown that the symmetry and positive definiteness of the acoustic tensor of the skeleton guarantee both hyperbolicity and the wave speed consistency of the equations.

APA, Harvard, Vancouver, ISO, and other styles

29

Li, Zhiqing, Chuan Tang, Ruilin Hu, and Yingxin Zhou. "RESEARCH ON MODEL FITTING AND STRENGTH CHARACTERISTICS OF CRITICAL STATE FOR EXPANSIVE SOIL." Journal of Civil Engineering and Management 19, no. 1 (January 16, 2013): 9–15. http://dx.doi.org/10.3846/13923730.2012.734857.

Full text

Abstract:

According to Mengzi expansive soil, consolidated drained tests and undrained tests are carried on under saturated and remoulded conditions. The stress-strain characteristics of saturated soil are researched systematically under different confining pressure, initial dry density, initial water content, shearing rate and drainage condition. The inherent unity of diversity of shearing strength for the same samples measured by different experimental methods is indicated according to the normalization of critical state test results. And the failure lines in p ‘- q - ν space of remoulded saturated expansive soil under consolidated drained and undrained conditions are attained. The hyperbolic curve model can fit well the weak hardening stress-strain curves and the exponential curve model can fit the weak softening stress-strain curves. The test results can provide technical parameters and theoretical help for shearing strength variation of slope during rainfall and strength state of soil structure in normal water level.

APA, Harvard, Vancouver, ISO, and other styles

30

Shen, Yang, Wen Jun Huang, Yan De Li, and Hai Dong Xu. "Calculation Method of Bearing Capacity Improvement of Soft Soil Foundation under Vacuum Preloading." Applied Mechanics and Materials 353-356 (August 2013): 352–56. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.352.

Full text

Abstract:

The theory of vacuum preloading was mainly focused on calculations of settlement and consolidation degree, but not on the bearing capacity improvement under vacuum preloading. Based on the Mohr-Coulombs failure criterion and elastic-plastic theory, the formula of bearing capacity improvement of vacuum preloading foundation was deduced under undrained condition. The consolidation and vacuum attenuation degree were taken into the consideration, and a calculation formula with fewer parameters by using CU total stress strength index was derived. Meanwhile the relation between bearing capacity and undrained shear strength was presented as well as that of bearing capacity and vertical effective stress increment.

APA, Harvard, Vancouver, ISO, and other styles

31

Kumruzzaman, Md, and Jian-Hua Yin. "Influences of principal stress direction and intermediate principal stress on the stress–strain–strength behaviour of completely decomposed granite." Canadian Geotechnical Journal 47, no. 2 (February 2010): 164–79. http://dx.doi.org/10.1139/t09-079.

Full text

Abstract:

The measurement and study of the stress–strain–strength behaviour of soils in general stress states involving the change of magnitudes and direction of the principal stresses are necessary and important. To investigate the strength behaviour under such conditions, consolidated undrained tests on remoulded hollow cylinder specimens of completely decomposed granite (CDG) were carried out using a hollow cylinder apparatus. Tests were conducted by maintaining a fixed principal stress direction with angle α from the vertical direction together with a fixed value of intermediate principal stress coefficient b. It is observed that the value of the friction angle decreases with an increase in α and the failure surface is anisotropic. There is an increase in friction angle with an increase in b value up to b = 0.25, and the friction angles are almost the same for b > 0.25. In addition, the behaviour of the soil in an undrained simple shear condition was examined. The simple shear condition is very near to the condition of α = 45° and b = 0.25. After having analyzed the test results of all hollow cylinder specimens, it was found that the strength anisotropy is very strong and is dependent on the principal stress direction and intermediate principal stress coefficient.

APA, Harvard, Vancouver, ISO, and other styles

32

Penumadu, Dayakar, Arumugam Skandarajah, and Jean-Lou Chameau. "Strain-rate effects in pressuremeter testing using a cuboidal shear device: experiments and modeling." Canadian Geotechnical Journal 35, no. 1 (February 1, 1998): 27–42. http://dx.doi.org/10.1139/t97-076.

Full text

Abstract:

The objective of the present research was to study the effect of rate of probe expansion in pressuremeter testing for cohesive soil. Emphasis in this paper was given to quantifying and modeling the effect of strain rate on the undrained shear strength. The strain path followed by an element of clay adjacent to the expanding probe was simulated using an automated flexible boundary cuboidal shear device (CSD) typically up to a magnitude of strain level of 10%. Two types of soil (kaolin, kaolin-silica mix) were used consistently for all the testing. Repeatable cubical cohesive specimens were obtained from a high water content slurry consolidation technique. K0 consolidation was performed by using a constant vertical stress - zero lateral strain boundary condition using a closed-loop pneumatic system. A series of strain-controlled tests with increasing strain rates from 0.01 to 5%/min was performed under undrained conditions. The effects of increase of strain rate on shear stress - strain behavior and undrained shear strength were quantified. A numerical model based on cylindrical cavity expansion theory which accounts for higher strain rate and its variation with radial distance from an expanding probe membrane was calibrated using the single-element CSD test data.Key words: strain rate, pressuremeter, stress-strain, shear strength, strain path, cavity expansion.

APA, Harvard, Vancouver, ISO, and other styles

33

Mallikarachchi, Hansini, and Kenichi Soga. "A Constitutive Model for Locally Drained Shear Bands in Globally Undrained Dense Sand." E3S Web of Conferences 92 (2019): 16005. http://dx.doi.org/10.1051/e3sconf/20199216005.

Full text

Abstract:

When saturated granular materials which are dilative in nature are subjected to the undrained deformation, their strength increases due to the generation of negative excess pore pressure. This phenomenon is known as dilative hardening and can be witnessed in saturated dense sand or rocks during very fast loading. However, experimental evidence of undrained biaxial compression tests of dense sand shows a limit to this dilative hardening due to the formation of shear bands. There is no consensus in the literature about the mechanism which triggers these shear bands in the dense dilative sand under isochoric constraint. The possible theoretical reasoning is the local drainage inside the specimen under the globally undrained condition, which is challenging to be monitored experimentally. Hence, both incept of localisation and post-bifurcation of the saturated undrained dense sand demand further numerical investigation. Pathological mesh dependency hinders the ability of the finite element method to represent the localisation without advanced regularisation methods. This paper attempt to provide a macroscopic constitutive behaviour of the undrained deformation of the saturated dense sand in the presence of a locally drained shear band. Discontinuation of dilatant hardening due to partial drainage between the shear band and the adjacent material is integrated into the constitutive model without changing governing equilibrium equations. Initially, a classical bifurcation analysis is conducted to detect the inception and inclination of the shear band based on the underlying drained deformation. Then a post-bifurcation analysis is carried out assuming an embedded drained or partially drained shear band at gauss points which satisfy bifurcation criterion. The smeared shear band approach is utilised to homogenise the constitutive relationship. It is observed that the dilatant hardening in the saturated undrained dense sand is reduced considerably due to the formation of shear bands.

APA, Harvard, Vancouver, ISO, and other styles

34

Been, Ken, and Michael Jefferies. "Stressdilatancy in very loose sand." Canadian Geotechnical Journal 41, no. 5 (September 1, 2004): 972–89. http://dx.doi.org/10.1139/t04-038.

Full text

Abstract:

Virtually all investigation of liquefaction has used undrained tests, and it has become common to represent the undrained strength in terms of a collapse surface or collapse stress ratio described by an effective friction angle. A difficulty with undrained tests is that they only allow observation of the interaction of elastic and plastic strain because of the imposed boundary condition (i.e., no drainage or zero volume change), precluding a proper understanding of an effective stress criterion for maximum undrained strength. Drained triaxial tests do not suffer from this shortcoming, and stressdilatancy of dense sands in drained shear is well established as a fundamental aspect of sand behaviour, based on micromechanical considerations. It is particularly interesting to consider the stressdilatancy behaviour of very loose sands in the context of soil liquefaction. Although there are some data in the literature on loose sand behaviour in drained triaxial compression, the majority of data are actually for sands markedly denser than sands showing static liquefaction in undrained tests. This paper therefore reports some laboratory testing of very loose sands, together with comparative undrained liquefaction data, and compares the loose behaviour to that of dense sand. These data are reduced to stressdilatancy form so that the fundamental aspects of loose soil behaviour can be seen and compared to flow rules used in constitutive models. The stressdilatancy of very loose sand shows no limiting stress ratio markedly less than that of the critical state. Moreover, the stressdilatancy trends of very loose sand are the same as those of dense sand. There is no evidence of "structural collapse" of the particulate arrangement of very loose sands, contrary to speculation associated with collapse surfaces in the literature. Explanations of sand liquefaction must seek other physical explanations of the soil behaviour.Key words: sand, constitutive relations, plasticity, liquefaction.

APA, Harvard, Vancouver, ISO, and other styles

35

Li, Qian, and Le Fu. "Research on Strength Characteristics of Expansive Soil." Applied Mechanics and Materials 109 (October 2011): 96–99. http://dx.doi.org/10.4028/www.scientific.net/amm.109.96.

Full text

Abstract:

According to expansive soil, consolidated drained tests and undrained tests are carried on under saturated and remoulded conditions. The stress-strain characteristics of saturated soil are researched systematically under different confining pressure, initial dry density, initial water content, shearing rate and drainage condition. The inherent unity of diversity of shearing strength for the same samples measured by different experimental methods is indicated according to the normalization of critical state test results.

APA, Harvard, Vancouver, ISO, and other styles

36

Darusman, Taryono, Daniel Murdiyarso, Impron Impron, Iswandi Anas Chaniago, and Dwi Puji Lestari. "Carbon Dynamics in Rewetted Tropical Peat Swamp Forests." Climate 10, no. 3 (March 3, 2022): 35. http://dx.doi.org/10.3390/cli10030035.

Full text

Abstract:

Degraded and drained peat swamp forests (PSFs) are major sources of carbon emissions in the forestry sector. Rewetting interventions aim to reduce carbon loss and to enhance the carbon stock. However, studies of rewetting interventions in tropical PSFs are still limited. This study examined the effect of rewetting interventions on carbon dynamics at a rewetted site and an undrained site. We measured aboveground carbon (AGC), belowground carbon (BGC), litterfall, heterotrophic components of soil respiration (Rh), methane emissions (CH4), and dissolved organic carbon (DOC) concentration at both sites. We found that the total carbon stock at the rewetted site was slightly lower than at the undrained site (1886.73 ± 87.69 and 2106.23 ± 214.33 Mg C ha−1, respectively). The soil organic carbon (SOC) was 1685 ± 61 Mg C ha−1 and 1912 ± 190 Mg C ha−1 at the rewetted and undrained sites, respectively, and the carbon from litterfall was 4.68 ± 0.30 and 3.92 ± 0.34 Mg C ha−1 year−1, respectively. The annual average Rh was 4.06 ± 0.02 Mg C ha−1 year−1 at the rewetted site and was 3.96 ± 0.16 Mg C ha−1 year−1 at the undrained site. In contrast, the annual average CH4 emissions were −0.0015 ± 0.00 Mg C ha−1 year−1 at the rewetted site and 0.056 ± 0.000 Mg C ha−1 year−1 at the undrained site. In the rewetted condition, carbon from litter may become stable over a longer period. Consequently, carbon loss and gain mainly depend on the magnitude of peat decomposition (Rh) and CH4 emissions.

APA, Harvard, Vancouver, ISO, and other styles

37

Wanatowski, Dariusz, Jian Chu, and Wai Lay Loke. "Drained instability of sand in plane strain." Canadian Geotechnical Journal 47, no. 4 (April 2010): 400–412. http://dx.doi.org/10.1139/t09-111.

Full text

Abstract:

Flowslide or failure of loose granular soil slopes is often explained using liquefaction or instability data obtained from undrained triaxial tests. However, under static loading conditions, the assumption of an undrained condition is not realistic for sand, particularly clean sand. Case studies have indicated that instability of granular soil can occur under essentially drained conditions (e.g., the Wachusett Dam failure in 1907). Laboratory studies on Changi sand by Chu et al. in 2003 have shown that sand can become unstable under completely drained conditions. However, these studies were carried out under axisymmetric conditions and thus, cannot be applied directly to the analysis of slope failures. In this paper, experimental data obtained from plane-strain tests are presented to study the instability behaviour of loose and dense sand under plane-strain conditions. Based on these test data, the conditions for the occurrence of drained instability in plane strain are established. Using the modified state parameter, the conditions for instability under both axisymmetric and plane-strain conditions can be unified. A framework for interpreting the instability conditions of sandy slopes developed under axisymmetric conditions also extends into plane-strain conditions.

APA, Harvard, Vancouver, ISO, and other styles

38

NAKAZAWA, Hiroshi, Kenji ISHIHARA, Yoshimichi TSUKAMOTO, and Toshiyuki KAMATA. "CHARACTERISTICS OF UNDRAINED SHEAR BEHAVIOR OF SANDY SOIL UNDER PARTIALLY SATURATED CONDITION." Doboku Gakkai Ronbunshuu C 63, no. 2 (2007): 334–43. http://dx.doi.org/10.2208/jscejc.63.334.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Wang, H., J. Koseki, and T. Sato. "p-Constant Condition Applied to Undrained Cyclic Triaxial Test of Unsaturated Soils." Geotechnical Testing Journal 40, no. 4 (May 5, 2017): 20160115. http://dx.doi.org/10.1520/gtj20160115.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Khatri, Vishwas N., and Jyant Kumar. "Vertical uplift resistance of circular plate anchors in clays under undrained condition." Computers and Geotechnics 36, no. 8 (October 2009): 1352–59. http://dx.doi.org/10.1016/j.compgeo.2009.06.008.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Khatri, Vishwas N., and Jyant Kumar. "Stability of an unsupported vertical circular excavation in clays under undrained condition." Computers and Geotechnics 37, no. 3 (April 2010): 419–24. http://dx.doi.org/10.1016/j.compgeo.2009.11.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Wu, Ze-Xiang, Christophe Dano, Pierre-Yves Hicher, and Zhen-Yu Yin. "Estimating normal effective stress degradation in sand under undrained simple shear condition." European Journal of Environmental and Civil Engineering 25, no. 1 (October 24, 2018): 170–89. http://dx.doi.org/10.1080/19648189.2018.1521750.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Szypcio, Zenon. "Stress-Dilatancy for Soils. Part II: Experimental Validation for Triaxial Tests." Studia Geotechnica et Mechanica 38, no. 4 (December 1, 2016): 59–65. http://dx.doi.org/10.1515/sgem-2016-0031.

Full text

Abstract:

Abstract Different forms of the stress-dilatancy relations obtained based on the frictional theory for the triaxial condition are presented. The analysed test data show that the shear resistance of many soils is purely frictional. The angle Φ0 represents the resistance of the soil as a combined effect of sliding and particle rolling on the macro-scale during shear at the critical frictional state. The stress-plastic dilatancy relations differ not only for triaxial compression and extension but also for drained and undrained conditions. The experiment investigated shows the correctness of the frictional state theory in the triaxial condition.

APA, Harvard, Vancouver, ISO, and other styles

44

Zhou, Hong Xing, Shao Heng He, Min Gao, Zhi Ding, and Tang Dai Xia. "Effect of Initial Consolidation Stress Path on Shear Behavior of Calcareous Sand." Key Engineering Materials 871 (January 2021): 349–56. http://dx.doi.org/10.4028/www.scientific.net/kem.871.349.

Full text

Abstract:

Calcareous sand is widely used as backfill material for land reclamation, but due to its special mechanical characteristics such as easily broken particles, calcareous sand foundation is facing more complex engineering problems. In this study, drained and undrained shear tests were carried out on calcareous sand samples from the South China Sea using K0 consolidation and isotropic consolidation conditions. It was found that the particle breakage of calcareous sand has obvious dependence on the initial consolidation stress path and drainage condition, thus showing different shear strength behavior. The particle breakage under drained shear is greater than that under undrained shear, and the particle breakage under isotropic consolidated shear is greater than that under K0 consolidated shear. The larger the particle breakage, the smaller the dilatancy and internal friction angle of calcareous sand. The dilatancy and internal friction angle of K0 consolidated specimen are larger than those of isotropic consolidated specimen. It is suggested that the actual stress path of calcareous sand should be considered in the engineering.

APA, Harvard, Vancouver, ISO, and other styles

45

Travascio, Francesco, Shihab Asfour, Roberto Serpieri, and Luciano Rosati. "Analysis of the consolidation problem of compressible porous media by a macroscopic variational continuum approach." Mathematics and Mechanics of Solids 22, no. 5 (December 23, 2015): 952–68. http://dx.doi.org/10.1177/1081286515616049.

Full text

Abstract:

This study presents an analysis of the stress-partitioning mechanism for fluid saturated poroelastic media in the transition from drained (e.g. slow deformations) to undrained (e.g. fast deformation) flow conditions. The goal of this analysis is to derive fundamental solutions for the general consolidation problem and to show how Terzaghi’s law is recovered as the limit undrained flow condition is approached. The approach is based on a variational macroscopic theory of porous media (VMTPM). First, the linearized form of VMTPM is expressed in a u– p dimensionless form. Subsequently, the behavior of the poroelastic system is investigated as a function of governing dimensionless numbers for the case of a displacement controlled compression test. The analysis carried out in this study produced two crucial results. First, in the limit of undrained flow, it confirmed that the solutions of the consolidation problem recover Terzaghi’s law. Second, it was found that a dimensionless parameter ([Formula: see text]), which solely depends on mixture porosity and Poisson ratio of the solid phase, discriminates two diametrically opposed mechanic responses of the poroelastic system. More specifically, when [Formula: see text] is positive, the solid stress in the mixture first increases and then relaxes to an equilibrium value ( stress relaxation). In contrast, when [Formula: see text], the solid stress monotonically tenses up to reach the equilibrium value ( stress tension).

APA, Harvard, Vancouver, ISO, and other styles

46

Sireesha, Dr G. "Effect of Reinforcement on Properties of Silty Sand." International Journal for Research in Applied Science and Engineering Technology 9, no. 12 (December 31, 2021): 1934–38. http://dx.doi.org/10.22214/ijraset.2021.39649.

Full text

Abstract:

Abstract: The variation of the stress-strain behavior and shear -parameters of reinforced silty sand is studied. The geotextiles were provided at different heights in the sample and tested in unconsolidated undrained condition. Two types of geotextiles, woven and nonwoven were used as reinforcement and the experiment was conducted at three water contents. Tests were performed on samples prepared at OMC, dry of OMC and wet of OMC in order to study the effect of water content. The results demonstrated that geotextile inclusion increases the peak strength, axial strain at failure. The sample was found to fail due to bulging between the layers. Keywords: Optimum Moisture Content, Maximum Dry Density, Unconsolidated Undrained, Deviator Stress, Normal Stress

APA, Harvard, Vancouver, ISO, and other styles

47

Yi, Fu, and Hong Yu Wang. "Normalized Stress-Strain Behavior of Yingkou Clay." Advanced Materials Research 838-841 (November 2013): 47–52. http://dx.doi.org/10.4028/www.scientific.net/amr.838-841.47.

Full text

Abstract:

In order to systemic study the normalized stress-strain relationship behavior of Yingkou clay. By the consolidated undrained triaxial sherar test of Yingkou clay, obtaining that stress-strain relationship is strain hardening under different confining pressures.A kind of cementation structure in the soil directly affects soft soil strength.And the paper contrast four kinds of normalized factors to study stress-strain characteristics,which are confining pressurethe average consolidation pressureand the ultimate value of principal stress.The results indicate that the normalized degree is more accurate when used value of principal stress and as normalized factor. Meanwhile the normalized stress-strain relationship of Yingkou clay under consolidated undrained condition is established,which can well predict the stress-strain relationship under different confining pressure.

APA, Harvard, Vancouver, ISO, and other styles

48

Amaratunga, A., and J. L. H. Grozic. "On the undrained unloading behaviour of gassy sands." Canadian Geotechnical Journal 46, no. 11 (November 2009): 1267–76. http://dx.doi.org/10.1139/t09-056.

Full text

Abstract:

Soils that contain large amounts of dissolved gas within the pore fluid are called gassy soils. Gassy soils are common in marine environments and it is important to further our understanding of the unloading behaviour of gassy soils because of their potential to initiate and propagate submarine slope failures. This paper focuses on the pore-pressure responses and volumetric strains of loose gassy sands under different undrained unloading stress paths in laboratory specimens. Special attention was given to the constant deviatoric stress (q-constant) undrained unloading stress path as it simulates the stress condition imposed by tidal drawdown — one of the potential triggers of landslides in gaseous marine sediments. Gas exsolution was observed when the pore pressure was reduced below the liquid gas saturation pressure. Upon further decreases in total stress, the resulting pore-pressure change was much less than the total stress change; hence, effective stress decreased rapidly and at a certain point the samples tested under the q-constant stress path collapsed. This paper has experimentally and theoretically shown that gas in free and (or) dissolved form is detrimental in undrained unloading stress paths.

APA, Harvard, Vancouver, ISO, and other styles

49

MIKAMI, Takeko, Koji ICHII, Kazuaki UEMURA, and Haruki NISHINA. "A model for strain increase of sand under cyclic shear in undrained condition." Japanese Geotechnical Journal 7, no. 1 (2012): 311–22. http://dx.doi.org/10.3208/jgs.7.311.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Kang, Jae-Mo, Jang-Guen Lee, Hak-Seung Kim, Sang-Yoon Lee, Byung-Hyun Ryu, and Nam-Jun Cho. "Effects of Freezing a Backfill Material under Undrained Condition on a Buried Pipe." Journal of the Korean Geotechnical Society 30, no. 8 (August 31, 2014): 39–47. http://dx.doi.org/10.7843/kgs.2014.30.8.39.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!