Influence of Degree of Compaction on Unsaturated Hydraulic Properties of a Compacted Completely Decomposed Granite
It is crucial to understand hydraulic properties, i.e., soil-water characteristic curve (SWCC) and unsaturated permeability function (UPF), of completely decomposed granite (CDG) for relevant engineering projects in southeastern China. Previous studies mainly focused on SWCCs of CDG, whereas UPFs of...
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| Format: | Article |
| Language: | English |
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Wiley
2020-01-01
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| Series: | Geofluids |
| Online Access: | http://dx.doi.org/10.1155/2020/7615361 |
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| author | Rui Chen Runqiang Tan Zhongkui Chen Yang Ping Zhen Mei |
| author_facet | Rui Chen Runqiang Tan Zhongkui Chen Yang Ping Zhen Mei |
| author_sort | Rui Chen |
| collection | DOAJ |
| description | It is crucial to understand hydraulic properties, i.e., soil-water characteristic curve (SWCC) and unsaturated permeability function (UPF), of completely decomposed granite (CDG) for relevant engineering projects in southeastern China. Previous studies mainly focused on SWCCs of CDG, whereas UPFs of CDG have not yet been well understood. In this study, the effects of the degree of compaction (DOC) on SWCCs and UPFs of CDG were investigated based on experiments where suction range was from 0 to 500 kPa. The microstructure of soil specimens was then analyzed by mercury intrusion porosimetry (MIP). Furthermore, the UPFs of CDG under different values of DOC were calculated using four prediction models and compared with experimental data. Results showed that the pore volume of specimens at higher DOC was smaller than that at lower DOC, and there were more macropores observed in specimens at lower DOC. Meanwhile, it was found that increasing compaction effort produced negligible influence on the volume of micropores. When the suction was less than 100 kPa, the permeability was reduced with the increase in DOC, due to the decrease of macropore volume. However, the influence of DOC on SWCCs and UPFs became marginal when the suction exceeded 100 kPa. The Fredlund and Xing model provided the best prediction of UPF among the four models when suction was smaller than air entry value (AEV). It is suggested that these models could be improved to capture UPFs at higher suctions than AEV by considering suction-induced volume contraction. |
| format | Article |
| id | doaj-art-4dbe8a4de027444baf4ad49b4c9ac6bb |
| institution | Kabale University |
| issn | 1468-8115 1468-8123 |
| language | English |
| publishDate | 2020-01-01 |
| publisher | Wiley |
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| series | Geofluids |
| spelling | doaj-art-4dbe8a4de027444baf4ad49b4c9ac6bb2025-02-03T05:53:25ZengWileyGeofluids1468-81151468-81232020-01-01202010.1155/2020/76153617615361Influence of Degree of Compaction on Unsaturated Hydraulic Properties of a Compacted Completely Decomposed GraniteRui Chen0Runqiang Tan1Zhongkui Chen2Yang Ping3Zhen Mei4School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, ChinaSchool of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, ChinaSchool of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, ChinaShenzhen Water Planning and Design Institute Co., Ltd., Shenzhen 518000, ChinaSchool of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, ChinaIt is crucial to understand hydraulic properties, i.e., soil-water characteristic curve (SWCC) and unsaturated permeability function (UPF), of completely decomposed granite (CDG) for relevant engineering projects in southeastern China. Previous studies mainly focused on SWCCs of CDG, whereas UPFs of CDG have not yet been well understood. In this study, the effects of the degree of compaction (DOC) on SWCCs and UPFs of CDG were investigated based on experiments where suction range was from 0 to 500 kPa. The microstructure of soil specimens was then analyzed by mercury intrusion porosimetry (MIP). Furthermore, the UPFs of CDG under different values of DOC were calculated using four prediction models and compared with experimental data. Results showed that the pore volume of specimens at higher DOC was smaller than that at lower DOC, and there were more macropores observed in specimens at lower DOC. Meanwhile, it was found that increasing compaction effort produced negligible influence on the volume of micropores. When the suction was less than 100 kPa, the permeability was reduced with the increase in DOC, due to the decrease of macropore volume. However, the influence of DOC on SWCCs and UPFs became marginal when the suction exceeded 100 kPa. The Fredlund and Xing model provided the best prediction of UPF among the four models when suction was smaller than air entry value (AEV). It is suggested that these models could be improved to capture UPFs at higher suctions than AEV by considering suction-induced volume contraction.http://dx.doi.org/10.1155/2020/7615361 |
| spellingShingle | Rui Chen Runqiang Tan Zhongkui Chen Yang Ping Zhen Mei Influence of Degree of Compaction on Unsaturated Hydraulic Properties of a Compacted Completely Decomposed Granite Geofluids |
| title | Influence of Degree of Compaction on Unsaturated Hydraulic Properties of a Compacted Completely Decomposed Granite |
| title_full | Influence of Degree of Compaction on Unsaturated Hydraulic Properties of a Compacted Completely Decomposed Granite |
| title_fullStr | Influence of Degree of Compaction on Unsaturated Hydraulic Properties of a Compacted Completely Decomposed Granite |
| title_full_unstemmed | Influence of Degree of Compaction on Unsaturated Hydraulic Properties of a Compacted Completely Decomposed Granite |
| title_short | Influence of Degree of Compaction on Unsaturated Hydraulic Properties of a Compacted Completely Decomposed Granite |
| title_sort | influence of degree of compaction on unsaturated hydraulic properties of a compacted completely decomposed granite |
| url | http://dx.doi.org/10.1155/2020/7615361 |
| work_keys_str_mv | AT ruichen influenceofdegreeofcompactiononunsaturatedhydraulicpropertiesofacompactedcompletelydecomposedgranite AT runqiangtan influenceofdegreeofcompactiononunsaturatedhydraulicpropertiesofacompactedcompletelydecomposedgranite AT zhongkuichen influenceofdegreeofcompactiononunsaturatedhydraulicpropertiesofacompactedcompletelydecomposedgranite AT yangping influenceofdegreeofcompactiononunsaturatedhydraulicpropertiesofacompactedcompletelydecomposedgranite AT zhenmei influenceofdegreeofcompactiononunsaturatedhydraulicpropertiesofacompactedcompletelydecomposedgranite |