Long -Term Deformation Of Some Gypseous Soils
Time-dependent deformation and stress relaxation in soils are important in a variety ofgeotechnical problems where long-term behavior is of concern.Previous studies on soils showed that the magnitude of delayed compression(creep) is controlled by compressibility and soil sensitivity in addition topr...
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| Format: | Article |
| Language: | English |
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Unviversity of Technology- Iraq
2008-12-01
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| Series: | Engineering and Technology Journal |
| Subjects: | |
| Online Access: | https://etj.uotechnology.edu.iq/article_26878_5b7ead2010bff00c107f11159b97c2c6.pdf |
| _version_ | 1797325259511169024 |
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| author | Mohammed Y. Fattah Yousif J. al-Shakarchi |
| author_facet | Mohammed Y. Fattah Yousif J. al-Shakarchi |
| author_sort | Mohammed Y. Fattah |
| collection | DOAJ |
| description | Time-dependent deformation and stress relaxation in soils are important in a variety ofgeotechnical problems where long-term behavior is of concern.Previous studies on soils showed that the magnitude of delayed compression(creep) is controlled by compressibility and soil sensitivity in addition topreconsolidation.In this paper, the time-dependent behavior of gypseous soils is investigated. Thesoils used in this study were brought from three locations at Al-Tar region west of Al-Najaf city in Iraq. These soils had gypsum content of (66%, 44% and 14.8%). Themineralogical and chemical properties of the soils were determined.Two series of tests were performed. In the first, collapsibility characteristics wereinvestigated for a long period (60 days) by conducting single and double oedometertests. In the second series, the effect of relative density on collapse with time wasinvestigated. The samples were compacted to 40%, 50% and 60% relative density andthen tested. The results of collapse tests showed that the relationship between thestrain and logarithm of effective stress has two vertical lines. The first one representsthe collapse settlement taking place within 24 hours, while the second one representsthe long-term collapse. The collapse potential in both single and double oedometertests increases when the gypsum content increases from (14.8%) to (66%) and whenthe initial void ratio increases.The results of double oedometer tests showed that the relationship between thecollapse potential and logarithm of time, for samples loaded to 800 kPa for 60 days,consist of three distinct segments. The first segment is represented by a curve concavedownward in which the compressibility gradually increases. The second segment is astraight line with a higher increase in the strain. The third segment which refers tocreep collapse depends on the gypsum content. Gypseous soil with low gypsumcontent (14.8%) exhibited significant decrease (5.21% at 24 hours to 7.16% at 60 days)in collapse potential with time. |
| first_indexed | 2024-03-08T06:06:59Z |
| format | Article |
| id | doaj.art-cd7cf7305d6749aa813094cc3948dfd6 |
| institution | Directory Open Access Journal |
| issn | 1681-6900 2412-0758 |
| language | English |
| last_indexed | 2024-03-08T06:06:59Z |
| publishDate | 2008-12-01 |
| publisher | Unviversity of Technology- Iraq |
| record_format | Article |
| series | Engineering and Technology Journal |
| spelling | doaj.art-cd7cf7305d6749aa813094cc3948dfd62024-02-04T17:52:57ZengUnviversity of Technology- IraqEngineering and Technology Journal1681-69002412-07582008-12-0126121461148310.30684/etj.26.12.326878Long -Term Deformation Of Some Gypseous SoilsMohammed Y. FattahYousif J. al-ShakarchiTime-dependent deformation and stress relaxation in soils are important in a variety ofgeotechnical problems where long-term behavior is of concern.Previous studies on soils showed that the magnitude of delayed compression(creep) is controlled by compressibility and soil sensitivity in addition topreconsolidation.In this paper, the time-dependent behavior of gypseous soils is investigated. Thesoils used in this study were brought from three locations at Al-Tar region west of Al-Najaf city in Iraq. These soils had gypsum content of (66%, 44% and 14.8%). Themineralogical and chemical properties of the soils were determined.Two series of tests were performed. In the first, collapsibility characteristics wereinvestigated for a long period (60 days) by conducting single and double oedometertests. In the second series, the effect of relative density on collapse with time wasinvestigated. The samples were compacted to 40%, 50% and 60% relative density andthen tested. The results of collapse tests showed that the relationship between thestrain and logarithm of effective stress has two vertical lines. The first one representsthe collapse settlement taking place within 24 hours, while the second one representsthe long-term collapse. The collapse potential in both single and double oedometertests increases when the gypsum content increases from (14.8%) to (66%) and whenthe initial void ratio increases.The results of double oedometer tests showed that the relationship between thecollapse potential and logarithm of time, for samples loaded to 800 kPa for 60 days,consist of three distinct segments. The first segment is represented by a curve concavedownward in which the compressibility gradually increases. The second segment is astraight line with a higher increase in the strain. The third segment which refers tocreep collapse depends on the gypsum content. Gypseous soil with low gypsumcontent (14.8%) exhibited significant decrease (5.21% at 24 hours to 7.16% at 60 days)in collapse potential with time.https://etj.uotechnology.edu.iq/article_26878_5b7ead2010bff00c107f11159b97c2c6.pdfgypseous soilcollapsetimerelative density |
| spellingShingle | Mohammed Y. Fattah Yousif J. al-Shakarchi Long -Term Deformation Of Some Gypseous Soils Engineering and Technology Journal gypseous soil collapse time relative density |
| title | Long -Term Deformation Of Some Gypseous Soils |
| title_full | Long -Term Deformation Of Some Gypseous Soils |
| title_fullStr | Long -Term Deformation Of Some Gypseous Soils |
| title_full_unstemmed | Long -Term Deformation Of Some Gypseous Soils |
| title_short | Long -Term Deformation Of Some Gypseous Soils |
| title_sort | long term deformation of some gypseous soils |
| topic | gypseous soil collapse time relative density |
| url | https://etj.uotechnology.edu.iq/article_26878_5b7ead2010bff00c107f11159b97c2c6.pdf |
| work_keys_str_mv | AT mohammedyfattah longtermdeformationofsomegypseoussoils AT yousifjalshakarchi longtermdeformationofsomegypseoussoils |