Impacts of Consolidation Time on the Critical Hydraulic Gradient of Newly Deposited Silty Seabed in the Yellow River Delta
The silty seabed in the Yellow River Delta (YRD) is exposed to deposition, liquefaction, and reconsolidation repeatedly, during which seepage flows are crucial to the seabed strength. In extreme cases, seepage flows could cause seepage failure (SF) in the seabed, endangering the offshore structures....
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doaj-30381c5c043847a791c59ac98130bca52021-04-02T21:40:41ZengMDPI AGJournal of Marine Science and Engineering2077-13122021-03-01927027010.3390/jmse9030270Impacts of Consolidation Time on the Critical Hydraulic Gradient of Newly Deposited Silty Seabed in the Yellow River DeltaMeiyun Tang0Yonggang Jia1Shaotong Zhang2Chenxi Wang3Hanlu Liu4Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao 266100, ChinaShandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao 266100, ChinaShandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao 266100, ChinaShandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao 266100, ChinaShandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Qingdao 266100, ChinaThe silty seabed in the Yellow River Delta (YRD) is exposed to deposition, liquefaction, and reconsolidation repeatedly, during which seepage flows are crucial to the seabed strength. In extreme cases, seepage flows could cause seepage failure (SF) in the seabed, endangering the offshore structures. A critical condition exists for the occurrence of SF, i.e., the critical hydraulic gradient (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula>). Compared with cohesionless sands, the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula> of cohesive sediments is more complex, and no universal evaluation theory is available yet. The present work first improved a self-designed annular flume to avoid SF along the sidewall, then simulated the SF process of the seabed with different consolidation times in order to explore the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula> of newly deposited silty seabed in the YRD. It is found that the theoretical formula for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula> of cohesionless soil grossly underestimated the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula> of cohesive soil. The <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula> range of silty seabed in the YRD was 8–16, which was significantly affected by the cohesion and was inversely proportional to the seabed fluidization degree. SF could “pump” the sediments vertically from the interior of the seabed with a contribution to sediment resuspension of up to 93.2–96.8%. The higher the consolidation degree, the smaller the contribution will be.https://www.mdpi.com/2077-1312/9/3/270seepage failurecritical hydraulic gradientexcess pore pressurefluidization degreeresuspension |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Meiyun Tang Yonggang Jia Shaotong Zhang Chenxi Wang Hanlu Liu |
spellingShingle |
Meiyun Tang Yonggang Jia Shaotong Zhang Chenxi Wang Hanlu Liu Impacts of Consolidation Time on the Critical Hydraulic Gradient of Newly Deposited Silty Seabed in the Yellow River Delta Journal of Marine Science and Engineering seepage failure critical hydraulic gradient excess pore pressure fluidization degree resuspension |
author_facet |
Meiyun Tang Yonggang Jia Shaotong Zhang Chenxi Wang Hanlu Liu |
author_sort |
Meiyun Tang |
title |
Impacts of Consolidation Time on the Critical Hydraulic Gradient of Newly Deposited Silty Seabed in the Yellow River Delta |
title_short |
Impacts of Consolidation Time on the Critical Hydraulic Gradient of Newly Deposited Silty Seabed in the Yellow River Delta |
title_full |
Impacts of Consolidation Time on the Critical Hydraulic Gradient of Newly Deposited Silty Seabed in the Yellow River Delta |
title_fullStr |
Impacts of Consolidation Time on the Critical Hydraulic Gradient of Newly Deposited Silty Seabed in the Yellow River Delta |
title_full_unstemmed |
Impacts of Consolidation Time on the Critical Hydraulic Gradient of Newly Deposited Silty Seabed in the Yellow River Delta |
title_sort |
impacts of consolidation time on the critical hydraulic gradient of newly deposited silty seabed in the yellow river delta |
publisher |
MDPI AG |
series |
Journal of Marine Science and Engineering |
issn |
2077-1312 |
publishDate |
2021-03-01 |
description |
The silty seabed in the Yellow River Delta (YRD) is exposed to deposition, liquefaction, and reconsolidation repeatedly, during which seepage flows are crucial to the seabed strength. In extreme cases, seepage flows could cause seepage failure (SF) in the seabed, endangering the offshore structures. A critical condition exists for the occurrence of SF, i.e., the critical hydraulic gradient (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula>). Compared with cohesionless sands, the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula> of cohesive sediments is more complex, and no universal evaluation theory is available yet. The present work first improved a self-designed annular flume to avoid SF along the sidewall, then simulated the SF process of the seabed with different consolidation times in order to explore the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula> of newly deposited silty seabed in the YRD. It is found that the theoretical formula for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula> of cohesionless soil grossly underestimated the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula> of cohesive soil. The <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>i</mi><mrow><mi>cr</mi></mrow></msub></mrow></semantics></math></inline-formula> range of silty seabed in the YRD was 8–16, which was significantly affected by the cohesion and was inversely proportional to the seabed fluidization degree. SF could “pump” the sediments vertically from the interior of the seabed with a contribution to sediment resuspension of up to 93.2–96.8%. The higher the consolidation degree, the smaller the contribution will be. |
topic |
seepage failure critical hydraulic gradient excess pore pressure fluidization degree resuspension |
url |
https://www.mdpi.com/2077-1312/9/3/270 |
work_keys_str_mv |
AT meiyuntang impactsofconsolidationtimeonthecriticalhydraulicgradientofnewlydepositedsiltyseabedintheyellowriverdelta AT yonggangjia impactsofconsolidationtimeonthecriticalhydraulicgradientofnewlydepositedsiltyseabedintheyellowriverdelta AT shaotongzhang impactsofconsolidationtimeonthecriticalhydraulicgradientofnewlydepositedsiltyseabedintheyellowriverdelta AT chenxiwang impactsofconsolidationtimeonthecriticalhydraulicgradientofnewlydepositedsiltyseabedintheyellowriverdelta AT hanluliu impactsofconsolidationtimeonthecriticalhydraulicgradientofnewlydepositedsiltyseabedintheyellowriverdelta |
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1721544713858711552 |