Analysis of the Liquefaction Potential at the Base of the San Marcos Dam (Cayambe, Ecuador)—A Validation in the Use of the Horizontal-to-Vertical Spectral Ratio

Ground liquefaction potential analysis is a fundamental characterization in areas with continuous seismic activity, such as Ecuador. Geotechnical liquefaction studies are usually approached from dynamic penetration tests, which pose problems both in their correct execution and in their evaluation. O...

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Main Authors: Olegario Alonso-Pandavenes, Francisco Javier Torrijo, Gabriela Torres
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Geosciences
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Online Access:https://www.mdpi.com/2076-3263/14/11/306
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author Olegario Alonso-Pandavenes
Francisco Javier Torrijo
Gabriela Torres
author_facet Olegario Alonso-Pandavenes
Francisco Javier Torrijo
Gabriela Torres
author_sort Olegario Alonso-Pandavenes
collection DOAJ
description Ground liquefaction potential analysis is a fundamental characterization in areas with continuous seismic activity, such as Ecuador. Geotechnical liquefaction studies are usually approached from dynamic penetration tests, which pose problems both in their correct execution and in their evaluation. Our research involves analyzing dynamic penetration tests and microtremor geophysical surveys (horizontal-to-vertical spectral ratio technique, HVSR) for analyzing the liquefaction potential at the base of the San Marcos dam, a reservoir located in Cayambe canton (Ecuador). Based on the investigations performed at the time of construction of the dam (drilling and geophysical refraction profiles) and the application of 20 microtremor observation stations via the HVSR technique, an analysis of the safety factor of liquefaction (<i>SF<sub>liq</sub></i>) was conducted using the 2001 Youd and Idriss formulation and the values of the standard penetration test (SPT) applied in granular materials (sands). In addition, the vulnerability index (<i>K<sub>g</sub></i>) proposed by Nakamura in 1989 was analyzed through the HVSR records related to the ground shear strain (<i>GSS</i>). The results obtained in the HVSR analysis indicate the presence of a zone of about 100 m length in the central part of the foot of the dam, whose <i>GSS</i> values identified a condition of susceptibility to liquefaction. In the same area, the SPT essays analysis in the P-8A drill hole also shows a potential susceptibility to liquefaction in earthquake conditions greater than a moment magnitude (<i>M<sub>w</sub></i>) of 4.5. That seismic event could occur in the area, for example, with a new activity condition of the nearby Cayambe volcano or even from an earthquake from the vicinity of the fractured zone.
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spelling doaj-art-98e2cb394e8042489f7ecde079f3f87c2024-11-26T18:05:41ZengMDPI AGGeosciences2076-32632024-11-01141130610.3390/geosciences14110306Analysis of the Liquefaction Potential at the Base of the San Marcos Dam (Cayambe, Ecuador)—A Validation in the Use of the Horizontal-to-Vertical Spectral RatioOlegario Alonso-Pandavenes0Francisco Javier Torrijo1Gabriela Torres2Faculty of Geology, Mining, Petroleum and Environmental Engineering-FIGEMPA, Universidad Central del Ecuador, Gilberto Gatto Sobral s/n, Quito 170521, EcuadorDepartment of Geotechnical Engineering, Research Centre for Architecture, Heritage and Management for Sustainable Development (PEGASO), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, SpainGEOTOP Ecuatorial Consulting, Quito 170507, EcuadorGround liquefaction potential analysis is a fundamental characterization in areas with continuous seismic activity, such as Ecuador. Geotechnical liquefaction studies are usually approached from dynamic penetration tests, which pose problems both in their correct execution and in their evaluation. Our research involves analyzing dynamic penetration tests and microtremor geophysical surveys (horizontal-to-vertical spectral ratio technique, HVSR) for analyzing the liquefaction potential at the base of the San Marcos dam, a reservoir located in Cayambe canton (Ecuador). Based on the investigations performed at the time of construction of the dam (drilling and geophysical refraction profiles) and the application of 20 microtremor observation stations via the HVSR technique, an analysis of the safety factor of liquefaction (<i>SF<sub>liq</sub></i>) was conducted using the 2001 Youd and Idriss formulation and the values of the standard penetration test (SPT) applied in granular materials (sands). In addition, the vulnerability index (<i>K<sub>g</sub></i>) proposed by Nakamura in 1989 was analyzed through the HVSR records related to the ground shear strain (<i>GSS</i>). The results obtained in the HVSR analysis indicate the presence of a zone of about 100 m length in the central part of the foot of the dam, whose <i>GSS</i> values identified a condition of susceptibility to liquefaction. In the same area, the SPT essays analysis in the P-8A drill hole also shows a potential susceptibility to liquefaction in earthquake conditions greater than a moment magnitude (<i>M<sub>w</sub></i>) of 4.5. That seismic event could occur in the area, for example, with a new activity condition of the nearby Cayambe volcano or even from an earthquake from the vicinity of the fractured zone.https://www.mdpi.com/2076-3263/14/11/306liquefactionHVSRSan Marcos damCayambe volcano<i>K<sub>g</sub></i> vulnerability indexground shear strain (<i>GSS</i>)
spellingShingle Olegario Alonso-Pandavenes
Francisco Javier Torrijo
Gabriela Torres
Analysis of the Liquefaction Potential at the Base of the San Marcos Dam (Cayambe, Ecuador)—A Validation in the Use of the Horizontal-to-Vertical Spectral Ratio
Geosciences
liquefaction
HVSR
San Marcos dam
Cayambe volcano
<i>K<sub>g</sub></i> vulnerability index
ground shear strain (<i>GSS</i>)
title Analysis of the Liquefaction Potential at the Base of the San Marcos Dam (Cayambe, Ecuador)—A Validation in the Use of the Horizontal-to-Vertical Spectral Ratio
title_full Analysis of the Liquefaction Potential at the Base of the San Marcos Dam (Cayambe, Ecuador)—A Validation in the Use of the Horizontal-to-Vertical Spectral Ratio
title_fullStr Analysis of the Liquefaction Potential at the Base of the San Marcos Dam (Cayambe, Ecuador)—A Validation in the Use of the Horizontal-to-Vertical Spectral Ratio
title_full_unstemmed Analysis of the Liquefaction Potential at the Base of the San Marcos Dam (Cayambe, Ecuador)—A Validation in the Use of the Horizontal-to-Vertical Spectral Ratio
title_short Analysis of the Liquefaction Potential at the Base of the San Marcos Dam (Cayambe, Ecuador)—A Validation in the Use of the Horizontal-to-Vertical Spectral Ratio
title_sort analysis of the liquefaction potential at the base of the san marcos dam cayambe ecuador a validation in the use of the horizontal to vertical spectral ratio
topic liquefaction
HVSR
San Marcos dam
Cayambe volcano
<i>K<sub>g</sub></i> vulnerability index
ground shear strain (<i>GSS</i>)
url https://www.mdpi.com/2076-3263/14/11/306
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AT franciscojaviertorrijo analysisoftheliquefactionpotentialatthebaseofthesanmarcosdamcayambeecuadoravalidationintheuseofthehorizontaltoverticalspectralratio
AT gabrielatorres analysisoftheliquefactionpotentialatthebaseofthesanmarcosdamcayambeecuadoravalidationintheuseofthehorizontaltoverticalspectralratio