Crack Characteristic and Permeability Change of Compacted Clay Liners with Different Liquid Limits under Dry-Wet Cycles
The crack characteristic and permeability change in six compacted clay liners (CCLs) under dry-wet cycles were studied. Results show that as soil liquid limit (LL) increases, the crack block (CB) number, crack ratio (CR), and crack length (CL) of the CCLs increase under the dry state. The CB sizes o...
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Wiley
2018-01-01
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| Series: | Advances in Civil Engineering |
| Online Access: | http://dx.doi.org/10.1155/2018/5796086 |
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| author | Yong Wan Qiang Xue Lei Liu ShanYong Wang |
| author_facet | Yong Wan Qiang Xue Lei Liu ShanYong Wang |
| author_sort | Yong Wan |
| collection | DOAJ |
| description | The crack characteristic and permeability change in six compacted clay liners (CCLs) under dry-wet cycles were studied. Results show that as soil liquid limit (LL) increases, the crack block (CB) number, crack ratio (CR), and crack length (CL) of the CCLs increase under the dry state. The CB sizes of all the six CCLs correspond to normal distribution. A piecewise linear relationship exists between crack parameters and soil LL, and the slope at LL < 50 is larger than the slope at LL > 50. The size of the representative elementary volume (REV) of cracked CCL decreases linearly with the increase in soil LL when LL < 50. The linear fitting result is REV = 90.5 – 1.6 LL, whereas REV change is inconspicuous with a mean value of approximately 10 cm when LL > 50. The sample size of the CCLs for the permeability test must be larger than REV. Before and after three dry-wet cycles, the permeability ratio (K3/k0) initially increases and eventually decreases as soil LL increases, and LL at the peak value of K3/k0 is 36.1%. However, linear relationships exist between permeability D-value (K3 − k0) and soil LL in a semilog coordinate system when LL < 50%, whereas the change in the permeability D-value is inconspicuous with a mean value of approximately 1.67 × 10−8 cm/s when LL > 50%. The volume and mean width of unclosed cracks are two main factors that determine the increase in permeability after dry-wet cycles. After three dry-wet cycles, these factors decrease as soil LL increases, thereby reducing the permeability D-value. |
| format | Article |
| id | doaj-art-26ca6db7d7bc4c3888fe7bab3c8ea5d7 |
| institution | Kabale University |
| issn | 1687-8086 1687-8094 |
| language | English |
| publishDate | 2018-01-01 |
| publisher | Wiley |
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| series | Advances in Civil Engineering |
| spelling | doaj-art-26ca6db7d7bc4c3888fe7bab3c8ea5d72025-08-20T03:54:48ZengWileyAdvances in Civil Engineering1687-80861687-80942018-01-01201810.1155/2018/57960865796086Crack Characteristic and Permeability Change of Compacted Clay Liners with Different Liquid Limits under Dry-Wet CyclesYong Wan0Qiang Xue1Lei Liu2ShanYong Wang3State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, ChinaState Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, ChinaState Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, ChinaARC Centre of Excellence for Geotechnical Science and Engineering, Civil, Surveying and Environmental Engineering, The University of Newcastle, Callaghan, NSW 2308, AustraliaThe crack characteristic and permeability change in six compacted clay liners (CCLs) under dry-wet cycles were studied. Results show that as soil liquid limit (LL) increases, the crack block (CB) number, crack ratio (CR), and crack length (CL) of the CCLs increase under the dry state. The CB sizes of all the six CCLs correspond to normal distribution. A piecewise linear relationship exists between crack parameters and soil LL, and the slope at LL < 50 is larger than the slope at LL > 50. The size of the representative elementary volume (REV) of cracked CCL decreases linearly with the increase in soil LL when LL < 50. The linear fitting result is REV = 90.5 – 1.6 LL, whereas REV change is inconspicuous with a mean value of approximately 10 cm when LL > 50. The sample size of the CCLs for the permeability test must be larger than REV. Before and after three dry-wet cycles, the permeability ratio (K3/k0) initially increases and eventually decreases as soil LL increases, and LL at the peak value of K3/k0 is 36.1%. However, linear relationships exist between permeability D-value (K3 − k0) and soil LL in a semilog coordinate system when LL < 50%, whereas the change in the permeability D-value is inconspicuous with a mean value of approximately 1.67 × 10−8 cm/s when LL > 50%. The volume and mean width of unclosed cracks are two main factors that determine the increase in permeability after dry-wet cycles. After three dry-wet cycles, these factors decrease as soil LL increases, thereby reducing the permeability D-value.http://dx.doi.org/10.1155/2018/5796086 |
| spellingShingle | Yong Wan Qiang Xue Lei Liu ShanYong Wang Crack Characteristic and Permeability Change of Compacted Clay Liners with Different Liquid Limits under Dry-Wet Cycles Advances in Civil Engineering |
| title | Crack Characteristic and Permeability Change of Compacted Clay Liners with Different Liquid Limits under Dry-Wet Cycles |
| title_full | Crack Characteristic and Permeability Change of Compacted Clay Liners with Different Liquid Limits under Dry-Wet Cycles |
| title_fullStr | Crack Characteristic and Permeability Change of Compacted Clay Liners with Different Liquid Limits under Dry-Wet Cycles |
| title_full_unstemmed | Crack Characteristic and Permeability Change of Compacted Clay Liners with Different Liquid Limits under Dry-Wet Cycles |
| title_short | Crack Characteristic and Permeability Change of Compacted Clay Liners with Different Liquid Limits under Dry-Wet Cycles |
| title_sort | crack characteristic and permeability change of compacted clay liners with different liquid limits under dry wet cycles |
| url | http://dx.doi.org/10.1155/2018/5796086 |
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