Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on Sand
The presence of minor details of the ground, including soil or rock masses, occurs more frequently than what is normally believed. Thin weak layers, shear bands, and slickensided surfaces can substantially affect the behaviour of foundations, as well as that of other geostructures. In fact, they can...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-09-01
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| Series: | Geosciences |
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| Online Access: | https://www.mdpi.com/2076-3263/11/9/392 |
| _version_ | 1797519146981785600 |
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| author | Maurizio Ziccarelli Marco Rosone |
| author_facet | Maurizio Ziccarelli Marco Rosone |
| author_sort | Maurizio Ziccarelli |
| collection | DOAJ |
| description | The presence of minor details of the ground, including soil or rock masses, occurs more frequently than what is normally believed. Thin weak layers, shear bands, and slickensided surfaces can substantially affect the behaviour of foundations, as well as that of other geostructures. In fact, they can affect the failure mechanisms, the ultimate bearing capacity of footings, and the safety factor of the geotechnical system. In this research, numerically conducted through Finite Element Code Plaxis 2D, the influence of a horizontal thin weak layer on the mechanical behaviour of shallow footings was evaluated. The obtained results prove that the weak layer strongly influences both the failure mechanism and the ultimate bearing capacity if its depth is lower than two to four times the footing width. In fact, under these circumstances, the failure mechanisms are always mixtilinear in shape because the shear strains largely develop on the weak layer. However, the reduction in the ultimate bearing capacity is a function of the difference between the shear strength of the foundation soil and the layer. The presence of a thin weak layer decreases the ultimate bearing capacity up to 90%. In conclusion, this research suggests that particular attention must be paid during detailed ground investigations to find thin weak layers. Based on the obtained results, it is convenient to increase the soil volume investigation to a depth equal to four times the width of the foundation. |
| first_indexed | 2024-03-10T07:38:57Z |
| format | Article |
| id | doaj.art-b63274a9b90447f29fa4245d0e829ae8 |
| institution | Directory Open Access Journal |
| issn | 2076-3263 |
| language | English |
| last_indexed | 2024-03-10T07:38:57Z |
| publishDate | 2021-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Geosciences |
| spelling | doaj.art-b63274a9b90447f29fa4245d0e829ae82023-11-22T13:16:16ZengMDPI AGGeosciences2076-32632021-09-0111939210.3390/geosciences11090392Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on SandMaurizio Ziccarelli0Marco Rosone1Department of Engineering, University of Palermo, 90128 Palermo, ItalyDepartment of Engineering, University of Palermo, 90128 Palermo, ItalyThe presence of minor details of the ground, including soil or rock masses, occurs more frequently than what is normally believed. Thin weak layers, shear bands, and slickensided surfaces can substantially affect the behaviour of foundations, as well as that of other geostructures. In fact, they can affect the failure mechanisms, the ultimate bearing capacity of footings, and the safety factor of the geotechnical system. In this research, numerically conducted through Finite Element Code Plaxis 2D, the influence of a horizontal thin weak layer on the mechanical behaviour of shallow footings was evaluated. The obtained results prove that the weak layer strongly influences both the failure mechanism and the ultimate bearing capacity if its depth is lower than two to four times the footing width. In fact, under these circumstances, the failure mechanisms are always mixtilinear in shape because the shear strains largely develop on the weak layer. However, the reduction in the ultimate bearing capacity is a function of the difference between the shear strength of the foundation soil and the layer. The presence of a thin weak layer decreases the ultimate bearing capacity up to 90%. In conclusion, this research suggests that particular attention must be paid during detailed ground investigations to find thin weak layers. Based on the obtained results, it is convenient to increase the soil volume investigation to a depth equal to four times the width of the foundation.https://www.mdpi.com/2076-3263/11/9/392strip footingbearing capacityweak layerfailure mechanismsFEM |
| spellingShingle | Maurizio Ziccarelli Marco Rosone Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on Sand Geosciences strip footing bearing capacity weak layer failure mechanisms FEM |
| title | Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on Sand |
| title_full | Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on Sand |
| title_fullStr | Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on Sand |
| title_full_unstemmed | Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on Sand |
| title_short | Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on Sand |
| title_sort | influence of a thin horizontal weak layer on the mechanical behaviour of shallow foundations resting on sand |
| topic | strip footing bearing capacity weak layer failure mechanisms FEM |
| url | https://www.mdpi.com/2076-3263/11/9/392 |
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