<abstract xmlns="http://www.w3.org/1999/xhtml"><p>The problem is a continuation of the research conducted at the University of Warmia and Mazury in Olsztyn, Institute of Building Engineering. It concerns the development of methods for the interpretation of the shear modulus measurements based on the tests conducted on a torsional shear (TS) apparatus. The issue has significant importance in determining the deformation parameters, essential to perform numerical simulations of the interaction between a geotechnical structure and the subsoil. The purpose of this study was to conduct a comparative analysis of the various methods of interpretation of research results based on direct and reverse analysis, as well as automated classification of the first cycle of the relationship between the shear stress and the shear strain components obtained from the TS test. The methodology for verification of the presented interpretative methods consists in carrying out a series of laboratory tests on non-cohesive and cohesive samples of different granulation and state parameters. The course of the research includes the following steps: elaboration of the granulometric composition of several samples of soil, determination of soil index properties and execution of TS tests. Various methods of interpretation of obtained results were taken into account, in addition to conducting a comparative analysis. The study used a non-standard interpretation approach consisting of analysing one-fourth of the hysteresis loop of the first load–unload cycle of the tested samples. The obtained results confirmed the hypothesis that it is possible to estimate the degradation value of the shear modulus based on a part of the TS test results carried out under quasi-monotonic load conditions. The proposed methods of interpreting test results have confirmed their high usefulness, which is devoid of the uncertainty associated with standardised resonant column/TS testing.</p></abstract>

The problem is a continuation of the research conducted at the University of Warmia and Mazury in Olsztyn, Institute of Building Engineering. It concerns the development of methods for the interpretation of the shear modulus measurements based on the tests conducted on a torsional shear (TS) apparatus. The issue has significant importance in determining the deformation parameters, essential to perform numerical simulations of the interaction between a geotechnical structure and the subsoil. The purpose of this study was to conduct a comparative analysis of the various methods of interpretation of research results based on direct and reverse analysis, as well as automated classification of the first cycle of the relationship between the shear stress and the shear strain components obtained from the TS test. The methodology for verification of the presented interpretative methods consists in carrying out a series of laboratory tests on non-cohesive and cohesive samples of different granulation and state parameters. The course of the research includes the following steps: elaboration of the granulometric composition of several samples of soil, determination of soil index properties and execution of TS tests. Various methods of interpretation of obtained results were taken into account, in addition to conducting a comparative analysis. The study used a non-standard interpretation approach consisting of analysing one-fourth of the hysteresis loop of the first load–unload cycle of the tested samples. The obtained results confirmed the hypothesis that it is possible to estimate the degradation value of the shear modulus based on a part of the TS test results carried out under quasi-monotonic load conditions. The proposed methods of interpreting test results have confirmed their high usefulness, which is devoid of the uncertainty associated with standardised resonant column/TS testing.

Interpretation of shear modulus degradation tests

Faculty of Geodesy, Geospatial and Civil Engineering

University of Warmia and Mazury in Olsztyn

Studia Geotechnica et Mechanica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

{"article-title":"Interpretation of shear modulus degradation tests"}

The problem is a continuation of the research conducted at the University of Warmia and Mazury in Olsztyn, Institute of Building Engineering. It concerns the...

Sample	Soil	Diameter, mm	Height, mm	Cell pressure, kPa	Maximum angle, mrad
S3057	Sandy silt saSi	70.2	141.4	100–300	17.2
S5919	Medium sand MSa (1)	70.0	143.1	50–200	2.2
S3935	Medium sand MSa (2)	72.8	143.2	50–400	1.3

Soil	G_s [-]	d₅₀[mm]	I_p	C_u[-]	e [-]	ρ [kg/m³]
Sandy silt saSi	2.66	0.047	0.11	17.1	0.67	1870
Medium sand MSa (1)	2.65	0.33	-	2.6	0.42	1860
Medium sand MSa (2)	2.65	0.33	-	4.0	0.37	1930

Interpretation of shear modulus degradation tests

Article Category: Research Article

Online veröffentlicht: 21. Sept. 2018

Seitenbereich: 125 - 132

Eingereicht: 22. März 2018

Akzeptiert: 10. Juni 2018

DOI: https://doi.org/10.2478/sgem-2018-0015

Schlüsselwörter
torsional shear, back analysis, cluster analysis, shear modulus, small strains

© 2018 Piotr Srokosz et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Figure 1

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Figure 15

Parameters of tested samples.

Parameters of tested soils.

Interpretation of shear modulus degradation tests

Article Category: Research Article

Online veröffentlicht: 21. Sept. 2018

Seitenbereich: 125 - 132

Eingereicht: 22. März 2018

Akzeptiert: 10. Juni 2018

DOI: https://doi.org/10.2478/sgem-2018-0015

Schlüsselwörtertorsional shear, back analysis, cluster analysis, shear modulus, small strains

© 2018 Piotr Srokosz et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Parameters of tested samples.

Parameters of tested soils.

Schlüsselwörter
torsional shear, back analysis, cluster analysis, shear modulus, small strains