scholarly journals SANDY SOILS DYNAMIC STRENGTH PARAMETERS ACCORDING TO TRIAXIAL TESTS

2019 ◽  
Vol 14 (2) ◽  
pp. 24-33
Author(s):  
E. A. Sentsova ◽  
M. S. Nikitin ◽  
E. A. Voznesensky
Keyword(s):  
Dynamic Loading ◽  
Critical State ◽  
Dynamic Strength ◽  
Strength Properties ◽  
Triaxial Tests ◽  
Strength Parameters ◽  
Dynamic Conditions ◽  
Angle Of Internal Friction ◽  
Static Conditions

Correct determination of strength properties is always relevant for the prediction of the mechanical behavior of soils and their massifs. Under static loading conditions, the issue is prominent in domestic and foreign literature, but the determination of strength properties under dynamic loading causes theoretical and methodical issues. All developed types of tests, to date, describe particular cases of the reaction of a soil foundation under dynamic loading, a general scientific approach of determination of soil strength parameters in dynamic conditions has not been developed. The article describes the features of determining the strength and strength parameters of sand in static and dynamic conditions in triaxial tests. A review of current views on this topic is provided. On the basis of triaxial tests the method of determining the phase transformation point and the failure point is described. On the basis of the Coulomb-Mohr's strength theory and the critical state approach the strength parameters are determined. The test results concluded that the destruction of sand under both static and dynamic conditions occurs with the same ratio of normal, shearing and mean effective stresses and is described by a single critical state line (CSL), presented in the form of a bilinear equation. It has been experimentally proved that the strength of sand under static and dynamic conditions is different, the strength parameters are the same, that’s why the angle of internal friction (φ) and cohesion (C) of sand can be determined only under static conditions. At the same time to quantify the strength of soil, to assess the possibility of destruction of the soil requires a correct assessment of pore pressure, which implies conducting dynamic tests or modeling its accumulation.

Dynamic Triaxial Test Research of Stage Change of Cohesive Soil

2013 ◽  
Vol 353-356 ◽  
pp. 937-940
Author(s):  
Xiao Yang Rong ◽  
Tian Hong Yang ◽  
Pei Tao Wang ◽  
Hong Wang ◽  
Yang Li
Keyword(s):  
Dynamic Load ◽  
Dynamic Strength ◽  
Cohesive Soil ◽  
Strength Properties ◽  
Triaxial Tests ◽  
Soil Deformation ◽  
Backbone Curve ◽  
Quantitative Basis ◽  
Stage Change ◽  
Soil Dynamic

With the STX-50 pneumatic-typed dynamic triaxial system, the undrained dynamic triaxial tests on the saturated cohesive soil are performed to study the dynamic strength properties. The changing process of the dynamic strength, backbone curve and the soil deformation of the cohesive soil under dynamic load are zoom analysis by stages to get their regularity. It is found that the stage change of the dynamic strength, backbone curve and the soil deformation all exist, which the stage I of the soil deformation has little damage, the stage III is not allowed, the stage II is determined by the importance of the concrete and the sensitive degree to the deformation. In order to analysis the deformation stability and stress stability of the formation in the effect of the dynamic load, provide qualitative and quantitative basis for the soil dynamic study.

scholarly journals Soil and rock strength parameters of the Shiraidake Landslide, Japan

2001 ◽  
Vol 23 ◽  
Author(s):  
Robert Jelinek ◽  
Prem Prasad Paudel ◽  
Hiroshi Omura
Keyword(s):  
Rock Strength ◽  
Sedimentary Rocks ◽  
Strength Properties ◽  
Triaxial Tests ◽  
Dry Density ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Strength Parameters ◽  
Consolidation Pressure ◽  
Early Tertiary

The Shiraidake area of northwest Kyushu has an extensive distribution of landslides. A series of undrained triaxial tests and unconfined compression tests were carried out to investigate the variation of strength properties in a selected borehole from the Shiraidake Landslide. It is a translational landslide (called the Hokusho-type in Japan) and is composed of the Early Tertiary and Quaternary sedimentary rocks that are prone to rapid weathering. Core rock samples and recompacted soil samples were used for the study. The results provided the fundamental characteristics of soil and rock under the triaxial and uniaxial tests, and indicated that the undrained behaviour of tested soils generally depends on the pre-shear consolidation pressure and dry density. In addition, the type of material used and the tests performed are important factors that influence the soil and rock strength.

Gross Error Elimination and Index Determination of Shearing Strength Parameters in Triaxial Test

2013 ◽  
Vol 353-356 ◽  
pp. 152-158
Author(s):  
Fang Wei
Keyword(s):  
Nonlinear Programming ◽  
Solution Process ◽  
Friction Angle ◽  
Triaxial Tests ◽  
Strength Parameters ◽  
Gross Error ◽  
Error Elimination ◽  
Shearing Strength ◽  
Programming Solution

In order to determine shearing strength parameters of triaxial tests(cohesion and friction angle), nonlinear programming solution was suggested based on “minimum square sum of distance”. After proving that the vertical distances between Mohr circles and the regressed strength line are distributed normally, data with gross error would be excluded; moreover, the only strength line, as well as cohesion and friction angle, could be determined. Combining with Matlab, the solution process became rapid, precise and intuitive. Some examples verified the applicability of suggested method finally.

scholarly journals Evaluation of the Impact of Hydrostatic Pressure and Lode Angle on the Strength of the Rock Mass Based on the Hoek–Brown Criterion

2015 ◽  
Vol 37 (2) ◽  
pp. 85-91
Author(s):  
Halina Marczak
Keyword(s):  
Rock Mass ◽  
Hydrostatic Pressure ◽  
Friction Angle ◽  
Stress Path ◽  
Strength Parameters ◽  
Angle Of Internal Friction ◽  
Minimum Principal Stress ◽  
Lode Angle ◽  
The Impact

Abstract Determination of the global uniaxial compressive strength of rock mass on the basis of the Hoek-Brown failure criterion requires knowledge of the strength parameters: cohesion and the angle of internal friction. In the conventional method for the determination of these parameters given by Balmer, they are expressed by the minimum principal stress. Thus, this method does not allow for the assessment of an impact of hydrostatic pressure and stress path on the value of cohesion, friction angle and global uniaxial compression of rock mass. This problem can be eliminated by using the Hoek-Brown criterion expressed by the invariants of the stress state. The influence of hydrostatic pressure and the Lode angle on the strength parameters of the rock mass was analysed.

scholarly journals SOIL SHEARING EQUIPMENT AND ACCURACY OF INVESTIGATION RESULTS

1998 ◽  
Vol 4 (2) ◽  
pp. 129-133
Author(s):  
Antanas Alikonis
Keyword(s):  
Soil Structure ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Undisturbed Soil ◽  
Angle Of Internal Friction ◽  
Soil Stress ◽  
Soil Shear Strength ◽  
The Usa ◽  
Constant Shear Rate

Civil engineering works require strength and stability. Soil subbase strength parameters, ie cohesion and the angle of internal friction are used in calculations. They are experimentally determined parameters. Determination of soil strength parameters by shearbox apparatus is being legalised by standards and used along with triaxial equipment in the USA, England, Austria, Russia, Lithuania and many other countries. Accuracy of investigation results depends on the construction of soil shearing apparatus. Soil stress on shearing plane should be registrated during the test, undisturbed soil structure should be preserved before shearing is started, friction between soil and parts of shearing apparatus should be avoided and constant shear rate assured during the whole test. Schemes of shearing apparatus presented in literature and standards show their inability of avoiding all the conditions mentioned above. The report presents ways of improving soil shearing equipment, which leads to a more precise investigation of soil shear strength parameters.

scholarly journals Determination of the critical state of granular materials with triaxial tests

2017 ◽  
Vol 57 (5) ◽  
pp. 733-744 ◽  
Author(s):  
E. Salvatore ◽  
G. Modoni ◽  
E. Andò ◽  
M. Albano ◽  
G. Viggiani
Keyword(s):  
Granular Materials ◽  
Critical State ◽  
Triaxial Tests

scholarly journals Вариационный подход к определению динамической прочности материала

2022 ◽  
Vol 92 (2) ◽  
pp. 274
Author(s):  
А.Д. Евстифеев ◽  
Г.А. Волков
Keyword(s):  
Test Performance ◽  
Tensile Tests ◽  
Strength Properties ◽  
Material Strength ◽  
Treatment Procedure ◽  
Performance Error ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars ◽  
Static Conditions

The problem of the determination of material strength properties through the Kolsky experimental technique is considered. Small size specimens of M1 copper alloy are tested on a split Hopkinson pressure bars equipment. The experimental data of tensile tests observed under both dynamic and quasi-static conditions are analysed within the framework of the incubation time criterion and the Sign-Perturbed Sums method. It is shown that the influence of a test performance error is considered in the data treatment procedure based on the developed method.

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