scholarly journals Effect of Total Stress Path and Gas Volume Change on Undrained Shear Strength of Gassy Clay

2021 ◽  
Vol 21 (11) ◽  
pp. 04021218
Author(s):  
Zhiwei Gao ◽  
Hongjian Cai
Keyword(s):  
Shear Strength ◽  
Volume Change ◽  
Stress Path ◽  
Undrained Shear Strength ◽  
Total Stress ◽  
Gas Volume ◽  
Undrained Shear

UNDRAINED SHEAR STRENGTH OF K0 CONSOLIDATED SOFT CLAYS UNDER TRIAXIAL AND PLANE STRAIN CONDITIONS

2014 ◽  
Vol 06 (03) ◽  
pp. 1450032 ◽  
Author(s):  
QIUSHENG WANG ◽  
XIULI DU ◽  
QIUMING GONG
Keyword(s):  
Shear Strength ◽  
Plane Strain ◽  
Yield Surface ◽  
Critical State ◽  
Volumetric Strain ◽  
Stress Path ◽  
Undrained Shear Strength ◽  
Triaxial Tests ◽  
Soft Clays ◽  
Undrained Shear

Theoretical formulas for predicting the undrained shear strength of K0 consolidated soft clays under the stress path related to triaxial and plane strain tests are presented within the framework of critical state soil mechanics. An inclined elliptical yield surface is adopted to take account of the initial anisotropic stress state. The undrained strength is determined by combining the undrained stress path in the volumetric stress–strain space and the initial yield surface in the deviator-mean stress space. The derived mathematical expressions are functions of the critical state frictional angle, the plastic volumetric strain ratio and the overconsolidation ratio, which can be simplified into the solutions for isotropically consolidated clays under triaxial tests or under plane strain tests. The results calculated by using the theoretical formulas obtained in this paper are in good agreement with the available collected test results. It indicates that these new formulas are applicable to triaxial and plane strain tests on normally and lightly to moderately overconsolidated soft clays.

Performance of clay samples reinforced with vertical granular columns

2007 ◽  
Vol 44 (1) ◽  
pp. 89-95 ◽  
Author(s):  
J Black ◽  
V Sivakumar ◽  
J D McKinley
Keyword(s):  
Shear Strength ◽  
Ground Improvement ◽  
Stress Path ◽  
Undrained Shear Strength ◽  
Replacement Ratio ◽  
Replacement Method ◽  
Single Column ◽  
Undrained Strength ◽  
Area Replacement Ratio ◽  
Undrained Shear

This paper reports an experimental study in which samples of soft kaolin clay (100 mm in diameter and 200 mm in height) were reinforced with vertical columns of sand and tested under triaxial conditions. Samples were reinforced with either a single column of sand of 32 mm diameter or three columns of sand, each of 20 mm diameter. The replacement method was used to form the columns. The columns were installed in the clay to depths of 120 and 200 mm. Tests were also carried out on samples that were not reinforced with sand columns. The samples were compressed under both drained and undrained conditions. It was found that the undrained shear strength of samples containing full-depth columns was greatly improved compared with that of the unreinforced samples. In the fully drained tests, the sample installed with a single column of 32 mm diameter exhibited better performance than the sample with three columns of 20 mm diameter, although the area replacement ratio in the case of the three 20 mm diameter columns was higher than that of the single 32 mm diameter column. However, the undrained strength of the composite material was not particularly affected by the number of columns.Key words: Ground improvement, undrained shear strength, consolidation, stress path, settlement.

Effects of frost on the mechanical behaviour of Champlain Sea clays

1991 ◽  
Vol 28 (5) ◽  
pp. 690-697 ◽  
Author(s):  
S. Leroueil ◽  
J. Tardif ◽  
M. Roy ◽  
P. La Rochelle ◽  
J.-M. Konrad
Keyword(s):  
Shear Strength ◽  
Key Words ◽  
Granular Materials ◽  
Volume Change ◽  
Mechanical Behaviour ◽  
Undrained Shear Strength ◽  
Freeze Thaw ◽  
Liquidity Index ◽  
Thaw Consolidation ◽  
Undrained Shear

This paper presents the mechanical behaviour of Champlain Sea clays when subjected to one cycle of freeze-thaw. It appears that most of the characteristics, namely, the undrained shear strength, the thaw consolidation volume change, and the strength after consolidation, are related to the initial liquidity index and can thus be easily predicted. Results also show that frozen–thawed Champlain Sea clays present a dilatant behaviour very similar to that of granular materials. Key words: sensitive clays, frost, laboratory, strength, compressibility.

scholarly journals Effects of compaction on soil undrained shear strength deteriorating during undrained cyclic loading and controlling seismic stability of embankment

2019 ◽  
Vol 92 ◽  
pp. 18003 ◽  
Author(s):  
Antoine Duttine ◽  
Fumio Tatsuoka ◽  
Kazuhiro Ueno
Keyword(s):  
Shear Strength ◽  
Cyclic Loading ◽  
Seismic Analysis ◽  
Undrained Shear Strength ◽  
Seismic Stability ◽  
Triaxial Tests ◽  
Response Analysis ◽  
Total Stress ◽  
Earth Fill ◽  
Undrained Shear

Effects of compaction on the undrained shear strength of saturated earth-fill dam materials are presented. Poorly and well compacted saturated soils may exhibit undrained shear strengths, respectively, significantly lower and higher than corresponding drained shear strength and this trend is amplified as the undrained strength deteriorates by preceding undrained cyclic loading. These features are implemented in a new simplified seismic analysis to evaluate residual deformation of earth-fill dams. The analysis consists of: 1) a modified Newmark sliding block analysis; and 2) a pseudo-static non-linear FEM analysis, both formulated in a unified framework based on the cumulative damage concept, total stress earthquake response analysis and a direct total stress modelling of undrained monotonic and cyclic stress-strain behaviours obtained by triaxial tests. The analysis simulates very well the collapse of an earth-fill dam by the 2011 Off the Pacific Coast of Tohoku Earthquake, Japan, and indicates a substantially higher seismic stability under the same conditions of the newly restored dam completed in 2017. Paramount effects of soil compaction on the seismic stability of earth-filled dam are demonstrated.

New stability method for embankments on clay foundations

1982 ◽  
Vol 19 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Robert P. Chapuis
Keyword(s):  
Shear Strength ◽  
Stress Analysis ◽  
Undrained Shear Strength ◽  
Direct Application ◽  
Published Data ◽  
Total Stress ◽  
Preconsolidation Pressure ◽  
Stability Method ◽  
Undrained Shear ◽  
Clay Foundations

The proposed method makes use of a conventional total stress analysis, corrected to take into consideration the preconsolidation pressure and the undrained shear strength profiles. Good results are obtained for seven well documented cases of embankment failures, the data of which allow a direct application of the proposed method. Many other failure cases, for which the published data are insufficient to allow such a direct application, are analysed on a statistical basis using a relationship between cuσp′ and Ip. Bjerrum's correction appears as a particular case, only statistically applicable, of the proposed method.

scholarly journals Evaluation of Undrained Shear Strength of Miocene Clay from the Weight Sounding Test (WST)

2017 ◽  
Vol 62 (2) ◽  
pp. 367-384
Author(s):  
Sebastian Olesiak
Keyword(s):  
Shear Strength ◽  
Field Testing ◽  
Field Investigation ◽  
Undrained Shear Strength ◽  
Cohesive Soils ◽  
Strength Parameters ◽  
Additional Measurement ◽  
Carpathian Foredeep ◽  
Innovative Solution ◽  
Undrained Shear

Abstract Soil strength parameters needed for the calculation of bearing capacity and stability are increasingly determined from field testing. This paper presents a method to determine the undrained shear strength cuWST of the soil, based on the Weight Sounding Test (WST). The innovative solution which allows for a significant reduction of equipment needed for geotechnical field investigation is presented. The proposed method is based on an additional measurement of the torque during testing. It then becomes possible to estimate the undrained shear strength, cuWST of the soil, using the correlation given in this paper. The research results presented in this paper were carried out on selected cohesive soils, Miocene clays from the Carpathian Foredeep.

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