Conversion of Triaxial Compression Strain–Time Curves from Stepwise Loading to Respective Loading
Numerous researchers of soil creep behavior adopt stepwise loading (SL) rather than respective loading (RL) to perform the triaxial creep tests. However, a complete continuous strain–time curve of SL needs to be converted into assumed curve clusters supposing obtained under RL before the deformation...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-09-01
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| Series: | Geotechnics |
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| Online Access: | https://www.mdpi.com/2673-7094/2/4/41 |
| _version_ | 1797457664435814400 |
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| author | Haigang Qu Dianrui Mu Zhong Nie Aiping Tang |
| author_facet | Haigang Qu Dianrui Mu Zhong Nie Aiping Tang |
| author_sort | Haigang Qu |
| collection | DOAJ |
| description | Numerous researchers of soil creep behavior adopt stepwise loading (SL) rather than respective loading (RL) to perform the triaxial creep tests. However, a complete continuous strain–time curve of SL needs to be converted into assumed curve clusters supposing obtained under RL before the deformation data are used to develop creep constitutive models. Classical methods realize the conversion mainly by focusing on the creep deformation parts and classifying them into linear and nonlinear compositions. Mostly, the linear parts are simply superposed while the nonlinear parts are complex to consider and so are neglected. Moreover, classical methods are not sufficiently valid to eliminate the stress history effect on the conversion. Here, a new method is proposed to achieve the conversion without neglecting the stress history effect. The method rebuilds the triaxial creep test mathematically and physically, adhering to the revising of energy. The method treats the tested deformation in its entirety, instead of distinguishing it into elastic, visco-elastic, plastic and creep (linear and nonlinear) deformation to convert respectively. The comparison among actual measured SL and RL strain–time curves and the curves converted by the new method proves the stress history effect should not be neglected. The higher the vertical load level, the larger the discrepancy between the RL and SL strain–time curve, and the disparity becomes larger with time. The new method highlights the necessity of considering the stress history effect in analysis and design for higher accuracy. The comparisons illustrate the conversion method at least produces more satisfactory results for clayey soil. Primarily examined, at the later stages of loading, the disparity in strain between the converted RL and measured RL decreases by 52.5%~53.5% compared with strain between the measured SL and measured RL. |
| first_indexed | 2024-03-09T16:26:16Z |
| format | Article |
| id | doaj.art-208f0aa136e94005a7bf7346fd78adda |
| institution | Directory Open Access Journal |
| issn | 2673-7094 |
| language | English |
| last_indexed | 2024-03-09T16:26:16Z |
| publishDate | 2022-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Geotechnics |
| spelling | doaj.art-208f0aa136e94005a7bf7346fd78adda2023-11-24T15:07:31ZengMDPI AGGeotechnics2673-70942022-09-012485587010.3390/geotechnics2040041Conversion of Triaxial Compression Strain–Time Curves from Stepwise Loading to Respective LoadingHaigang Qu0Dianrui Mu1Zhong Nie2Aiping Tang3School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, ChinaSchool of Civil Engineering, Harbin Institute of Technology, Harbin 150090, ChinaEngineering Research Institute of Appraisal and Strengthening of Shandong Jianzhu University Co., Ltd., Jinan 250014, ChinaSchool of Civil Engineering, Harbin Institute of Technology, Harbin 150090, ChinaNumerous researchers of soil creep behavior adopt stepwise loading (SL) rather than respective loading (RL) to perform the triaxial creep tests. However, a complete continuous strain–time curve of SL needs to be converted into assumed curve clusters supposing obtained under RL before the deformation data are used to develop creep constitutive models. Classical methods realize the conversion mainly by focusing on the creep deformation parts and classifying them into linear and nonlinear compositions. Mostly, the linear parts are simply superposed while the nonlinear parts are complex to consider and so are neglected. Moreover, classical methods are not sufficiently valid to eliminate the stress history effect on the conversion. Here, a new method is proposed to achieve the conversion without neglecting the stress history effect. The method rebuilds the triaxial creep test mathematically and physically, adhering to the revising of energy. The method treats the tested deformation in its entirety, instead of distinguishing it into elastic, visco-elastic, plastic and creep (linear and nonlinear) deformation to convert respectively. The comparison among actual measured SL and RL strain–time curves and the curves converted by the new method proves the stress history effect should not be neglected. The higher the vertical load level, the larger the discrepancy between the RL and SL strain–time curve, and the disparity becomes larger with time. The new method highlights the necessity of considering the stress history effect in analysis and design for higher accuracy. The comparisons illustrate the conversion method at least produces more satisfactory results for clayey soil. Primarily examined, at the later stages of loading, the disparity in strain between the converted RL and measured RL decreases by 52.5%~53.5% compared with strain between the measured SL and measured RL.https://www.mdpi.com/2673-7094/2/4/41soft soilcreepstrain–time curvestepwise loadingrespective loading |
| spellingShingle | Haigang Qu Dianrui Mu Zhong Nie Aiping Tang Conversion of Triaxial Compression Strain–Time Curves from Stepwise Loading to Respective Loading Geotechnics soft soil creep strain–time curve stepwise loading respective loading |
| title | Conversion of Triaxial Compression Strain–Time Curves from Stepwise Loading to Respective Loading |
| title_full | Conversion of Triaxial Compression Strain–Time Curves from Stepwise Loading to Respective Loading |
| title_fullStr | Conversion of Triaxial Compression Strain–Time Curves from Stepwise Loading to Respective Loading |
| title_full_unstemmed | Conversion of Triaxial Compression Strain–Time Curves from Stepwise Loading to Respective Loading |
| title_short | Conversion of Triaxial Compression Strain–Time Curves from Stepwise Loading to Respective Loading |
| title_sort | conversion of triaxial compression strain time curves from stepwise loading to respective loading |
| topic | soft soil creep strain–time curve stepwise loading respective loading |
| url | https://www.mdpi.com/2673-7094/2/4/41 |
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