Shear Modulus of a Carbonate Sand–Silt Mixture with THF Hydrate
The maximum shear modulus (<i>G<sub>max</sub></i>) is an important factor determining soil deformation, and it is closely related to engineering safety and seafloor stability. In this study, a series of bender element tests was carried out to investigate the <i>G<sub...
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MDPI AG
2022-10-01
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| Series: | Journal of Marine Science and Engineering |
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| Online Access: | https://www.mdpi.com/2077-1312/10/10/1519 |
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| author | Yuzhe Ren C. F. Chiu Lu Ma Y. P. Cheng Litong Ji Chao Jiang |
| author_facet | Yuzhe Ren C. F. Chiu Lu Ma Y. P. Cheng Litong Ji Chao Jiang |
| author_sort | Yuzhe Ren |
| collection | DOAJ |
| description | The maximum shear modulus (<i>G<sub>max</sub></i>) is an important factor determining soil deformation, and it is closely related to engineering safety and seafloor stability. In this study, a series of bender element tests was carried out to investigate the <i>G<sub>max</sub></i> of a hydrate-bearing carbonate sand (CS)–silt mixture. The soil mixture adopted a CS:silt ratio of 1:4 by weight to mimic the fine-grained deposit of the South China Sea (SCS). Tetrahydrofuran (THF) was used to form the hydrate. Special specimen preparation procedures were adopted to form THF hydrate inside the intraparticle voids of the CS. The test results indicate that hydrate contributed to a significant part of the skeletal stiffness of the hydrate-bearing CS–silt mixture, and its <i>G<sub>max</sub></i> at 5% hydrate saturation (<i>S<sub>h</sub></i>) was 4–6 times that of the host soil mixture. Such stiffness enhancement at a low <i>S<sub>h</sub></i> may be related to the cementation hydrate morphology. However, the <i>G<sub>max</sub></i> of the hydrate-bearing CS–silt mixture was also sensitive to the effective stress for an <i>S<sub>h</sub></i> ranging between 5% and 31%, implying that the frame-supporting hydrate morphology also plays a key role in the skeletal stiffness of the soil mixture. Neither the existing cementation models nor the theoretical frame-supporting (i.e., Biot–Gassmann theory by Lee (BGTL)), could alone provide a satisfactory prediction of the test results. Thus, further theoretical study involving a combination of cementation and frame-supporting models is essential to understand the effects of complicated hydrate morphologies on the stiffness of soil with a substantial amount of intraparticle voids. |
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| last_indexed | 2024-03-09T20:00:40Z |
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| series | Journal of Marine Science and Engineering |
| spelling | doaj.art-2133a1fc443f40adabfe8dca46403b452023-11-24T00:45:28ZengMDPI AGJournal of Marine Science and Engineering2077-13122022-10-011010151910.3390/jmse10101519Shear Modulus of a Carbonate Sand–Silt Mixture with THF HydrateYuzhe Ren0C. F. Chiu1Lu Ma2Y. P. Cheng3Litong Ji4Chao Jiang5Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210098, ChinaGuangdong Engineering Center for Structure Safety and Health Monitoring, Shantou University, Shantou 515063, ChinaCollege of Architecture, Anhui Science and Technology University, Bengbu 232002, ChinaDepartment of Civil, Environmental and Geomatic Engineering, University College London, London WC1E 6BT, UKNanjing TKA Technology, 6 Xiaohang Road, Yuhuatai District, Nanjing 210012, ChinaKey Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210098, ChinaThe maximum shear modulus (<i>G<sub>max</sub></i>) is an important factor determining soil deformation, and it is closely related to engineering safety and seafloor stability. In this study, a series of bender element tests was carried out to investigate the <i>G<sub>max</sub></i> of a hydrate-bearing carbonate sand (CS)–silt mixture. The soil mixture adopted a CS:silt ratio of 1:4 by weight to mimic the fine-grained deposit of the South China Sea (SCS). Tetrahydrofuran (THF) was used to form the hydrate. Special specimen preparation procedures were adopted to form THF hydrate inside the intraparticle voids of the CS. The test results indicate that hydrate contributed to a significant part of the skeletal stiffness of the hydrate-bearing CS–silt mixture, and its <i>G<sub>max</sub></i> at 5% hydrate saturation (<i>S<sub>h</sub></i>) was 4–6 times that of the host soil mixture. Such stiffness enhancement at a low <i>S<sub>h</sub></i> may be related to the cementation hydrate morphology. However, the <i>G<sub>max</sub></i> of the hydrate-bearing CS–silt mixture was also sensitive to the effective stress for an <i>S<sub>h</sub></i> ranging between 5% and 31%, implying that the frame-supporting hydrate morphology also plays a key role in the skeletal stiffness of the soil mixture. Neither the existing cementation models nor the theoretical frame-supporting (i.e., Biot–Gassmann theory by Lee (BGTL)), could alone provide a satisfactory prediction of the test results. Thus, further theoretical study involving a combination of cementation and frame-supporting models is essential to understand the effects of complicated hydrate morphologies on the stiffness of soil with a substantial amount of intraparticle voids.https://www.mdpi.com/2077-1312/10/10/1519tetrahydrofuran hydratecarbonate sandsiltmaximum shear modulusbender element test |
| spellingShingle | Yuzhe Ren C. F. Chiu Lu Ma Y. P. Cheng Litong Ji Chao Jiang Shear Modulus of a Carbonate Sand–Silt Mixture with THF Hydrate Journal of Marine Science and Engineering tetrahydrofuran hydrate carbonate sand silt maximum shear modulus bender element test |
| title | Shear Modulus of a Carbonate Sand–Silt Mixture with THF Hydrate |
| title_full | Shear Modulus of a Carbonate Sand–Silt Mixture with THF Hydrate |
| title_fullStr | Shear Modulus of a Carbonate Sand–Silt Mixture with THF Hydrate |
| title_full_unstemmed | Shear Modulus of a Carbonate Sand–Silt Mixture with THF Hydrate |
| title_short | Shear Modulus of a Carbonate Sand–Silt Mixture with THF Hydrate |
| title_sort | shear modulus of a carbonate sand silt mixture with thf hydrate |
| topic | tetrahydrofuran hydrate carbonate sand silt maximum shear modulus bender element test |
| url | https://www.mdpi.com/2077-1312/10/10/1519 |
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