Investigating the Influence of a Pre-Existing Shear Band on the Seismic Response of Ideal Step-like Slopes Subjected to Weak Motions: Preliminary Results
The assessment of slope susceptibility to seismically-induced displacements receives wide attention in the geotechnical earthquake engineering field, but the alteration of the seismic wave inside the slope and at the ground surface due to the presence of a shear band confining a quiescent landslide...
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MDPI AG
2023-05-01
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| Series: | Geosciences |
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| Online Access: | https://www.mdpi.com/2076-3263/13/5/148 |
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| author | Gaetano Falcone Gaetano Elia Annamaria di Lernia |
| author_facet | Gaetano Falcone Gaetano Elia Annamaria di Lernia |
| author_sort | Gaetano Falcone |
| collection | DOAJ |
| description | The assessment of slope susceptibility to seismically-induced displacements receives wide attention in the geotechnical earthquake engineering field, but the alteration of the seismic wave inside the slope and at the ground surface due to the presence of a shear band confining a quiescent landslide body is rarely investigated. This paper describes the preliminary results of the numerical analysis of two step-like FE models, reproducing a gentle slope and steep cutting subjected to weak earthquakes, thus focusing on seismic wave amplification processes only. The results show that the higher the thickness of the weakened zone, the higher the maximum value of the amplification factors predicted at the ground surface. For gentle slopes affected by a landslide body confined by a thick shear band, the highest amplification factors are expected in the longer period range of 0.7–1.1 s, while the highest level of amplification is achieved in the intermediate period interval of 0.4–0.8 s in the case of steep slopes. In addition, the parasitic vertical component of acceleration can be considerably amplified beyond the crest and at the toe of the slope for increasing band thickness, especially in the case of steep topography, for which the effects of the shear band morphology enhance those related to the topographic profile. Finally, the fundamental frequency of the sloping deposit is not particularly affected by the presence of the shear band, while the amplitude of the amplification function at the fundamental frequency is clearly related to its thickness. |
| first_indexed | 2024-03-11T03:41:08Z |
| format | Article |
| id | doaj.art-00986270af9145a4a2145e2f5af578d5 |
| institution | Directory Open Access Journal |
| issn | 2076-3263 |
| language | English |
| last_indexed | 2024-03-11T03:41:08Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Geosciences |
| spelling | doaj.art-00986270af9145a4a2145e2f5af578d52023-11-18T01:31:07ZengMDPI AGGeosciences2076-32632023-05-0113514810.3390/geosciences13050148Investigating the Influence of a Pre-Existing Shear Band on the Seismic Response of Ideal Step-like Slopes Subjected to Weak Motions: Preliminary ResultsGaetano Falcone0Gaetano Elia1Annamaria di Lernia2Department of Civil, Environmental, Land, Building Engineering and Chemistry (DICATECh), Technical University of Bari, Via Orabona 4, 70125 Bari, ItalyDepartment of Civil, Environmental, Land, Building Engineering and Chemistry (DICATECh), Technical University of Bari, Via Orabona 4, 70125 Bari, ItalyDepartment of Civil, Environmental, Land, Building Engineering and Chemistry (DICATECh), Technical University of Bari, Via Orabona 4, 70125 Bari, ItalyThe assessment of slope susceptibility to seismically-induced displacements receives wide attention in the geotechnical earthquake engineering field, but the alteration of the seismic wave inside the slope and at the ground surface due to the presence of a shear band confining a quiescent landslide body is rarely investigated. This paper describes the preliminary results of the numerical analysis of two step-like FE models, reproducing a gentle slope and steep cutting subjected to weak earthquakes, thus focusing on seismic wave amplification processes only. The results show that the higher the thickness of the weakened zone, the higher the maximum value of the amplification factors predicted at the ground surface. For gentle slopes affected by a landslide body confined by a thick shear band, the highest amplification factors are expected in the longer period range of 0.7–1.1 s, while the highest level of amplification is achieved in the intermediate period interval of 0.4–0.8 s in the case of steep slopes. In addition, the parasitic vertical component of acceleration can be considerably amplified beyond the crest and at the toe of the slope for increasing band thickness, especially in the case of steep topography, for which the effects of the shear band morphology enhance those related to the topographic profile. Finally, the fundamental frequency of the sloping deposit is not particularly affected by the presence of the shear band, while the amplitude of the amplification function at the fundamental frequency is clearly related to its thickness.https://www.mdpi.com/2076-3263/13/5/148seismic slope analysispre-existing shear bandsamplification factorsseismic hazardFE numerical modelling |
| spellingShingle | Gaetano Falcone Gaetano Elia Annamaria di Lernia Investigating the Influence of a Pre-Existing Shear Band on the Seismic Response of Ideal Step-like Slopes Subjected to Weak Motions: Preliminary Results Geosciences seismic slope analysis pre-existing shear bands amplification factors seismic hazard FE numerical modelling |
| title | Investigating the Influence of a Pre-Existing Shear Band on the Seismic Response of Ideal Step-like Slopes Subjected to Weak Motions: Preliminary Results |
| title_full | Investigating the Influence of a Pre-Existing Shear Band on the Seismic Response of Ideal Step-like Slopes Subjected to Weak Motions: Preliminary Results |
| title_fullStr | Investigating the Influence of a Pre-Existing Shear Band on the Seismic Response of Ideal Step-like Slopes Subjected to Weak Motions: Preliminary Results |
| title_full_unstemmed | Investigating the Influence of a Pre-Existing Shear Band on the Seismic Response of Ideal Step-like Slopes Subjected to Weak Motions: Preliminary Results |
| title_short | Investigating the Influence of a Pre-Existing Shear Band on the Seismic Response of Ideal Step-like Slopes Subjected to Weak Motions: Preliminary Results |
| title_sort | investigating the influence of a pre existing shear band on the seismic response of ideal step like slopes subjected to weak motions preliminary results |
| topic | seismic slope analysis pre-existing shear bands amplification factors seismic hazard FE numerical modelling |
| url | https://www.mdpi.com/2076-3263/13/5/148 |
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