Analysis of Negative Skin Friction on a Single Pile Based on the Effective Stress Method and the Finite Element Method
Negative skin friction (NSF) of piles in recent filling or soft area is an important effect factor of pile bearing capacity. Since field experiments on NSF are time consuming and it is difficult to large surcharge loads in experimental research, a unified calculation method of pile positive/negative...
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MDPI AG
2022-04-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/9/4125 |
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| author | Yuedong Wu Yuzhe Ren Jian Liu Lu Ma |
| author_facet | Yuedong Wu Yuzhe Ren Jian Liu Lu Ma |
| author_sort | Yuedong Wu |
| collection | DOAJ |
| description | Negative skin friction (NSF) of piles in recent filling or soft area is an important effect factor of pile bearing capacity. Since field experiments on NSF are time consuming and it is difficult to large surcharge loads in experimental research, a unified calculation method of pile positive/negative skin friction was established based on the effective stress method for investigation. The closed-form analytical solutions for calculating the pile skin friction corresponding to the plastic and elastic state were derived respectively. Meanwhile, the axial load of a single pile under different distribution forms of the pile skin friction was deduced. The calculation method was verified by comparing with an in-situ test. Furthermore, a computer model, which was established by the finite element method, was used to study the effect of the friction coefficient, consolidation time, consolidation pressure, drainage condition, and pressure ratio on the distribution of NSF and the location of neutral point. The results show that the effect of the friction coefficient, consolidation time, and pressure ratio on the NSF were significant. The friction coefficient increased from 0.05 to 0.4, the position of the neutral point rose by 22%, and the drag load of pile shaft was obviously increased. The effect of consolidation pressure and drainage conditions on the neutral point were relatively less, but they had a great influence on the distribution and magnitude of NSF. Furthermore, under different consolidation pressures, the normalized maximum axial load, <i>F<sub>max</sub></i>/<i>p</i>, of the pile shaft had a good linear relationship with the pressure ratio, <i>n</i>, and the slopes were the same. |
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| format | Article |
| id | doaj.art-42ad8b2e9dcc4db1b2fbe381f5f3d380 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T04:23:44Z |
| publishDate | 2022-04-01 |
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| series | Applied Sciences |
| spelling | doaj.art-42ad8b2e9dcc4db1b2fbe381f5f3d3802023-11-23T07:44:36ZengMDPI AGApplied Sciences2076-34172022-04-01129412510.3390/app12094125Analysis of Negative Skin Friction on a Single Pile Based on the Effective Stress Method and the Finite Element MethodYuedong Wu0Yuzhe Ren1Jian Liu2Lu Ma3Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210098, ChinaKey Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210098, ChinaKey Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210098, ChinaCollege of Architecture, Anhui Science and Technology University, Bengbu 232002, ChinaNegative skin friction (NSF) of piles in recent filling or soft area is an important effect factor of pile bearing capacity. Since field experiments on NSF are time consuming and it is difficult to large surcharge loads in experimental research, a unified calculation method of pile positive/negative skin friction was established based on the effective stress method for investigation. The closed-form analytical solutions for calculating the pile skin friction corresponding to the plastic and elastic state were derived respectively. Meanwhile, the axial load of a single pile under different distribution forms of the pile skin friction was deduced. The calculation method was verified by comparing with an in-situ test. Furthermore, a computer model, which was established by the finite element method, was used to study the effect of the friction coefficient, consolidation time, consolidation pressure, drainage condition, and pressure ratio on the distribution of NSF and the location of neutral point. The results show that the effect of the friction coefficient, consolidation time, and pressure ratio on the NSF were significant. The friction coefficient increased from 0.05 to 0.4, the position of the neutral point rose by 22%, and the drag load of pile shaft was obviously increased. The effect of consolidation pressure and drainage conditions on the neutral point were relatively less, but they had a great influence on the distribution and magnitude of NSF. Furthermore, under different consolidation pressures, the normalized maximum axial load, <i>F<sub>max</sub></i>/<i>p</i>, of the pile shaft had a good linear relationship with the pressure ratio, <i>n</i>, and the slopes were the same.https://www.mdpi.com/2076-3417/12/9/4125negative skin frictionpile–soil interactioneffective stress methodfinite element method |
| spellingShingle | Yuedong Wu Yuzhe Ren Jian Liu Lu Ma Analysis of Negative Skin Friction on a Single Pile Based on the Effective Stress Method and the Finite Element Method Applied Sciences negative skin friction pile–soil interaction effective stress method finite element method |
| title | Analysis of Negative Skin Friction on a Single Pile Based on the Effective Stress Method and the Finite Element Method |
| title_full | Analysis of Negative Skin Friction on a Single Pile Based on the Effective Stress Method and the Finite Element Method |
| title_fullStr | Analysis of Negative Skin Friction on a Single Pile Based on the Effective Stress Method and the Finite Element Method |
| title_full_unstemmed | Analysis of Negative Skin Friction on a Single Pile Based on the Effective Stress Method and the Finite Element Method |
| title_short | Analysis of Negative Skin Friction on a Single Pile Based on the Effective Stress Method and the Finite Element Method |
| title_sort | analysis of negative skin friction on a single pile based on the effective stress method and the finite element method |
| topic | negative skin friction pile–soil interaction effective stress method finite element method |
| url | https://www.mdpi.com/2076-3417/12/9/4125 |
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