Undrained Shear Strength Characteristics of Natural Silty Clay

2013 ◽  
Vol 405-408 ◽  
pp. 285-289
Author(s):  
Jie Yin ◽  
Yong Hong Miao
Keyword(s):  
Shear Strength ◽  
Stress State ◽  
Water Content ◽  
Yield Stress ◽  
Undrained Shear Strength ◽  
Strength Characteristics ◽  
Silty Clay ◽  
Undisturbed Samples ◽  
Undisturbed Sample ◽  
Undrained Shear

Triaxial consolidation undrained shear tests were carried out on both undisturbed and reconstituted samples of natural silty clay to investigate their undrained shear strength characteristics. Test results suggest that the strength envelope of the undisturbed sample is composed by two straight lines, which is different from that of the strength envelopes of reconstituted samples showing a straight line through the origin. Undrained shear strength of undisturbed samples are larger than corresponding reconstituted samples due to the resistance of soil structure in the pre-yield stress state. In the post-yield stress state, however, strength envelope of the undisturbed sample lies among the reconstituted samples with different initial water contents. Undrained shear strength for undisturbed samples in the post-yield stress state and reconstituted samples can be well correlated with the water content under different confining stress, which implies that undrained shear strength mainly depends on the current water content.

Determination of the consistency limits of soils by the fall cone test

1986 ◽  
Vol 23 (2) ◽  
pp. 241-246 ◽  
Author(s):  
Y. Wasti ◽  
M. H. Bezirci
Keyword(s):  
Shear Strength ◽  
Key Words ◽  
Water Content ◽  
Strength Criterion ◽  
Undrained Shear Strength ◽  
Wide Range ◽  
Undrained Strength ◽  
Content Range ◽  
Undrained Shear

The liquid and plastic limits for a variety of natural and artificial soils covering a wide range of plasticity, as determined by the Casagrande method and the fall cone test and based on a strength criterion, were compared. To check the validity of the strength criterion, the undrained shear strength of these soils has been determined with a laboratory vane over the water content range between these limits. A limited comparison of the undrained strength values obtained from the vane test and fall cone test is also given. Key words: Atterberg limits, consistency, fall cone, laboratory vane, shear strength.

scholarly journals The undrained shear strength characteristics of silty sand: an experimental study of the effect of fines

2011 ◽  
Vol 64 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Mostefa Belkhatir ◽  
Hanifi Missoum ◽  
Ahmed Arab ◽  
Noureddine Della ◽  
Tom Schanz
Keyword(s):  
Experimental Study ◽  
Shear Strength ◽  
Undrained Shear Strength ◽  
Silty Sand ◽  
Strength Characteristics ◽  
Undrained Shear

Effects of Electro Osmotic Consolidation in South West of Johor: Small Laboratory Scale

2014 ◽  
Vol 803 ◽  
pp. 255-264
Author(s):  
Khairul Nizar Mohd Yusof ◽  
Fauziah Ahmad ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Muhammad Faheem Mohd Tahir
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Clay Soil ◽  
Soft Clay ◽  
Soil Improvement ◽  
Undrained Shear Strength ◽  
Engineering Structures ◽  
Vertical Loading ◽  
South West ◽  
Undrained Shear

Clay soil is one of the problematic soils due to its natural states which have low bearing capacity and high compressibility. The effect and problem of the clay soil characteristic creates a problem for construction especially excessive settlement and this can lead to unstable and potential cracks of engineering structures. At presents, there are few of soil improvement types can be carried out to overcome these problems, and electro osmotic consolidation is one of the options. This method has been applied many years ago especially in european countries. The study encompasses the determination of water content, atterberg’s limits and undrained shear strength after electro osmotic consolidation treatment of clay soils taken from 0.5 m and 1.5 m at southwest part of johor. All the samples were tested according to BS1377:1990. An experimental study was implemented in a pvc cylinder tube having dimensions of 300 mm height and 100 mm diameter. In the results of electro osmotic consolidation tests by installing copper spring electrodes, the measured undrained shear strength was increased considerably at the anodes especially compared to the initial undrained shear strength due to electro osmosis process and consolidation. As laboratory studies of its measurement have shown, the application of electro osmotic consolidation after the application of a direct current applied voltage of 10 volts, at the anodes especially: (i) a decrease by approximately 35% in water content; (ii) an increase around 29% in undrained shear strength; and (iii) a decrease about 21% in index plasticity. The results obtained in this study shows that the electro osmotic enhanced 15 kpa vertical loading consolidation is a feasible approach in strengthening of south west soft clay in johor. It can be clearly suggested that the higher the voltage applied in the system, the higher readings of undrained shear strength and the lower of water content especially at the anodes.

scholarly journals Correlation between Compaction Characteristics with undrained Shear Strength of Soils found in Burayu Town

2021 ◽  
Author(s):  
SOLOMON KORMU ◽  
Alemineh Sorsa
Keyword(s):  
Shear Strength ◽  
Linear Regression ◽  
Soil Compaction ◽  
Undrained Shear Strength ◽  
Coefficient Of Determination ◽  
Red Clay ◽  
Compaction Characteristics ◽  
Undisturbed Samples ◽  
Undrained Shear

Abstract The shear strength of the soil is an important factor to know the internal resistance of soil against external loads causing shearing forces. Shear strength parameters are mandatory for the analysis of load bearing capacity of the soil, the stability of Geotechnical structures and in analysing stress and strain characteristics of soils. The undrained shear strength is one type of shear strength parameter. This parameter is conducted by undisturbed samples. But due to handling, transportation, release of overburden pressure and poor laboratory conditions, it is difficult to obtain accurate undisturbed samples. So, prediction of undrained shear strength parameters (cu) for cohesive soil with the help of compaction characteristics provides a good alternative to minimize this problem. Therefore, this study was conducted to develop the correlation between undrained shear strength values with soil compaction characteristics specifically located in Burayu town. The study was carried out using thirty samples collected from the town. By using the test result regression based statistical analysis was carried out to develop the intended correlation. The parameters considered for this study are Atterberg's limits, Grain size analysis, Specific gravity, Compaction tests and unconfined compression test. The test procedures were based on AASHTO and ASTM laboratory test standards. These parameters are used to establish equations of correlations between undrained shear strength values with soil compaction. The soil type found in Burayu town was highly plastic red clay soil. Based on both single and multiple linear regression analysis relatively good correlation is obtained by combining undrained shear strength (qu ) with maximum dry density and optimum moisture content of red clay soil. From the correlation analysis the equations developed are qu = - 3105 + 1625 MDD + 40.9 OMC with coefficient of determination of R2 =0.828 for multiple linear regression and qu= - 1473 + 57.8 OMC and qu= - 4861 + 3910 MDD with coefficient of determination of R2=0.787 and R2 =0.601 for single linear regression respectively. Generally, the intended correlation obtained from the study area fulfil the basic requirement of regression.

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